sw test tool: Improve readability of tcp options

    option='\\x00\\x00\\x00\\x00'
->  option=str('\\x00' * 4)

    option='\\x11\\x11\\x11\\x11'
->  option=str('\\x11' * 4)

Signed-off-by: Yuichi Ito <ito.yuichi0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

82 files changed, 848 insertions, 848 deletions

diff --git a/ryu/tests/switch/of13/action/00_OUTPUT.json b/ryu/tests/switch/of13/action/00_OUTPUT.json
index 65b4f6ff..afcc1571 100644
--- a/ryu/tests/switch/of13/action/00_OUTPUT.json
+++ b/ryu/tests/switch/of13/action/00_OUTPUT.json
@@ -28,13 +28,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
 
@@ -69,13 +69,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/11_COPY_TTL_OUT.json b/ryu/tests/switch/of13/action/11_COPY_TTL_OUT.json
index 9783ddbb..eb0f6142 100644
--- a/ryu/tests/switch/of13/action/11_COPY_TTL_OUT.json
+++ b/ryu/tests/switch/of13/action/11_COPY_TTL_OUT.json
@@ -44,14 +44,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=32)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -101,14 +101,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=32, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=32)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=32, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/12_COPY_TTL_IN.json b/ryu/tests/switch/of13/action/12_COPY_TTL_IN.json
index f9f0b583..678d362a 100644
--- a/ryu/tests/switch/of13/action/12_COPY_TTL_IN.json
+++ b/ryu/tests/switch/of13/action/12_COPY_TTL_IN.json
@@ -44,14 +44,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -101,14 +101,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=32, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/15_SET_MPLS_TTL.json b/ryu/tests/switch/of13/action/15_SET_MPLS_TTL.json
index f6658072..5ee372a6 100644
--- a/ryu/tests/switch/of13/action/15_SET_MPLS_TTL.json
+++ b/ryu/tests/switch/of13/action/15_SET_MPLS_TTL.json
@@ -46,14 +46,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=127)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -105,14 +105,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=127)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/16_DEC_MPLS_TTL.json b/ryu/tests/switch/of13/action/16_DEC_MPLS_TTL.json
index 7c88f450..c0f907a3 100644
--- a/ryu/tests/switch/of13/action/16_DEC_MPLS_TTL.json
+++ b/ryu/tests/switch/of13/action/16_DEC_MPLS_TTL.json
@@ -44,14 +44,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=63)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -101,14 +101,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=63)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/17_PUSH_VLAN.json b/ryu/tests/switch/of13/action/17_PUSH_VLAN.json
index b2e15feb..a5694126 100644
--- a/ryu/tests/switch/of13/action/17_PUSH_VLAN.json
+++ b/ryu/tests/switch/of13/action/17_PUSH_VLAN.json
@@ -45,14 +45,14 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -103,14 +103,14 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/17_PUSH_VLAN_multiple.json b/ryu/tests/switch/of13/action/17_PUSH_VLAN_multiple.json
index 62daffe3..ad7b5781 100644
--- a/ryu/tests/switch/of13/action/17_PUSH_VLAN_multiple.json
+++ b/ryu/tests/switch/of13/action/17_PUSH_VLAN_multiple.json
@@ -46,7 +46,7 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
@@ -54,7 +54,7 @@
                     "svlan(pcp=3, cfi=0, vid=100, ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -106,7 +106,7 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
@@ -114,7 +114,7 @@
                     "svlan(pcp=3, cfi=0, vid=100, ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/18_POP_VLAN.json b/ryu/tests/switch/of13/action/18_POP_VLAN.json
index aface7ff..c185dd83 100644
--- a/ryu/tests/switch/of13/action/18_POP_VLAN.json
+++ b/ryu/tests/switch/of13/action/18_POP_VLAN.json
@@ -51,13 +51,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -114,13 +114,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/19_PUSH_MPLS.json b/ryu/tests/switch/of13/action/19_PUSH_MPLS.json
index 2eee31cb..4f87a93f 100644
--- a/ryu/tests/switch/of13/action/19_PUSH_MPLS.json
+++ b/ryu/tests/switch/of13/action/19_PUSH_MPLS.json
@@ -45,14 +45,14 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -103,14 +103,14 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/19_PUSH_MPLS_multiple.json b/ryu/tests/switch/of13/action/19_PUSH_MPLS_multiple.json
index 95910621..2694e9de 100644
--- a/ryu/tests/switch/of13/action/19_PUSH_MPLS_multiple.json
+++ b/ryu/tests/switch/of13/action/19_PUSH_MPLS_multiple.json
@@ -46,7 +46,7 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
@@ -54,7 +54,7 @@
                     "mpls(bsb=0, label=100, exp=3, ttl=64)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -106,7 +106,7 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
@@ -114,7 +114,7 @@
                     "mpls(bsb=0, label=100, exp=3, ttl=64)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/20_POP_MPLS.json b/ryu/tests/switch/of13/action/20_POP_MPLS.json
index 8bc70a5c..9d042cee 100644
--- a/ryu/tests/switch/of13/action/20_POP_MPLS.json
+++ b/ryu/tests/switch/of13/action/20_POP_MPLS.json
@@ -46,13 +46,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -104,13 +104,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/23_SET_NW_TTL_IPv4.json b/ryu/tests/switch/of13/action/23_SET_NW_TTL_IPv4.json
index 7a540e4a..94a7cbe9 100644
--- a/ryu/tests/switch/of13/action/23_SET_NW_TTL_IPv4.json
+++ b/ryu/tests/switch/of13/action/23_SET_NW_TTL_IPv4.json
@@ -45,13 +45,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -103,14 +103,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -198,13 +198,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -291,13 +291,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/23_SET_NW_TTL_IPv6.json b/ryu/tests/switch/of13/action/23_SET_NW_TTL_IPv6.json
index dd0bfd37..51ad3835 100644
--- a/ryu/tests/switch/of13/action/23_SET_NW_TTL_IPv6.json
+++ b/ryu/tests/switch/of13/action/23_SET_NW_TTL_IPv6.json
@@ -45,13 +45,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=32, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -103,14 +103,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=32, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -198,13 +198,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=32, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -291,13 +291,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=32, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/24_DEC_NW_TTL_IPv4.json b/ryu/tests/switch/of13/action/24_DEC_NW_TTL_IPv4.json
index 28d4ef58..456b7e6e 100644
--- a/ryu/tests/switch/of13/action/24_DEC_NW_TTL_IPv4.json
+++ b/ryu/tests/switch/of13/action/24_DEC_NW_TTL_IPv4.json
@@ -43,13 +43,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=63)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -99,14 +99,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=63)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -192,13 +192,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=63)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -283,13 +283,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=63)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/24_DEC_NW_TTL_IPv6.json b/ryu/tests/switch/of13/action/24_DEC_NW_TTL_IPv6.json
index 86650270..c6fa6fad 100644
--- a/ryu/tests/switch/of13/action/24_DEC_NW_TTL_IPv6.json
+++ b/ryu/tests/switch/of13/action/24_DEC_NW_TTL_IPv6.json
@@ -43,13 +43,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=63, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -99,14 +99,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=63, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -192,13 +192,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=63, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -283,13 +283,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=63, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/03_ETH_DST.json b/ryu/tests/switch/of13/action/25_SET_FIELD/03_ETH_DST.json
index db9e3b51..ae1414e7 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/03_ETH_DST.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/03_ETH_DST.json
@@ -50,13 +50,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -112,13 +112,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/04_ETH_SRC.json b/ryu/tests/switch/of13/action/25_SET_FIELD/04_ETH_SRC.json
index 56d34ac4..fcc57fa8 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/04_ETH_SRC.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/04_ETH_SRC.json
@@ -50,13 +50,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -112,13 +112,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/05_ETH_TYPE.json b/ryu/tests/switch/of13/action/25_SET_FIELD/05_ETH_TYPE.json
index f88fda8c..980a6bb3 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/05_ETH_TYPE.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/05_ETH_TYPE.json
@@ -50,13 +50,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34888)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -112,13 +112,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34888)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/06_VLAN_VID.json b/ryu/tests/switch/of13/action/25_SET_FIELD/06_VLAN_VID.json
index 389426e9..72b02085 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/06_VLAN_VID.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/06_VLAN_VID.json
@@ -51,14 +51,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=203, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -115,14 +115,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=203, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/07_VLAN_PCP.json b/ryu/tests/switch/of13/action/25_SET_FIELD/07_VLAN_PCP.json
index 888503da..d43ca781 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/07_VLAN_PCP.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/07_VLAN_PCP.json
@@ -57,14 +57,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -127,14 +127,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/08_IP_DSCP_IPv4.json b/ryu/tests/switch/of13/action/25_SET_FIELD/08_IP_DSCP_IPv4.json
index a4bf2bfd..5127614f 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/08_IP_DSCP_IPv4.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/08_IP_DSCP_IPv4.json
@@ -56,13 +56,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=64, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -125,14 +125,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=64, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -231,13 +231,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=64, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -335,13 +335,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=64, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/08_IP_DSCP_IPv6.json b/ryu/tests/switch/of13/action/25_SET_FIELD/08_IP_DSCP_IPv6.json
index 46ec48a4..c23a224e 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/08_IP_DSCP_IPv6.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/08_IP_DSCP_IPv6.json
@@ -56,13 +56,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -125,14 +125,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -231,13 +231,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -335,13 +335,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/09_IP_ECN_IPv4.json b/ryu/tests/switch/of13/action/25_SET_FIELD/09_IP_ECN_IPv4.json
index 68ccb592..a262e06b 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/09_IP_ECN_IPv4.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/09_IP_ECN_IPv4.json
@@ -56,13 +56,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=33, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -125,14 +125,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=33, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -231,13 +231,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=33, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -335,13 +335,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=33, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/09_IP_ECN_IPv6.json b/ryu/tests/switch/of13/action/25_SET_FIELD/09_IP_ECN_IPv6.json
index 5b9e48f3..1efff538 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/09_IP_ECN_IPv6.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/09_IP_ECN_IPv6.json
@@ -56,13 +56,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=33)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -125,14 +125,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=33)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -231,13 +231,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=33)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -335,13 +335,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=33)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/10_IP_PROTO_IPv4.json b/ryu/tests/switch/of13/action/25_SET_FIELD/10_IP_PROTO_IPv4.json
index 9d885168..d208f625 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/10_IP_PROTO_IPv4.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/10_IP_PROTO_IPv4.json
@@ -56,13 +56,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=17, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -125,14 +125,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=17, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -231,13 +231,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=17, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -335,13 +335,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=17, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/10_IP_PROTO_IPv6.json b/ryu/tests/switch/of13/action/25_SET_FIELD/10_IP_PROTO_IPv6.json
index 466ed507..c3e0a66a 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/10_IP_PROTO_IPv6.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/10_IP_PROTO_IPv6.json
@@ -56,13 +56,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=17, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -125,14 +125,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=17, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -231,13 +231,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=17, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -335,13 +335,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=17, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/11_IPV4_SRC.json b/ryu/tests/switch/of13/action/25_SET_FIELD/11_IPV4_SRC.json
index a9e1d71e..af7a048a 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/11_IPV4_SRC.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/11_IPV4_SRC.json
@@ -56,13 +56,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='10.10.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -125,14 +125,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='10.10.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -231,13 +231,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='10.10.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -335,13 +335,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='10.10.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/12_IPV4_DST.json b/ryu/tests/switch/of13/action/25_SET_FIELD/12_IPV4_DST.json
index 9c084ae9..c476c8bf 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/12_IPV4_DST.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/12_IPV4_DST.json
@@ -56,13 +56,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='10.10.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -125,14 +125,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='10.10.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -231,13 +231,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='10.10.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -335,13 +335,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='10.10.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/13_TCP_SRC_IPv4.json b/ryu/tests/switch/of13/action/25_SET_FIELD/13_TCP_SRC_IPv4.json
index f6cb679e..420ce485 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/13_TCP_SRC_IPv4.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/13_TCP_SRC_IPv4.json
@@ -62,13 +62,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=12345)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -137,14 +137,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=12345)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -249,13 +249,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=12345)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -359,13 +359,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=12345)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/13_TCP_SRC_IPv6.json b/ryu/tests/switch/of13/action/25_SET_FIELD/13_TCP_SRC_IPv6.json
index 4863f9b5..9e17530f 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/13_TCP_SRC_IPv6.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/13_TCP_SRC_IPv6.json
@@ -62,13 +62,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=12345)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -137,14 +137,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=12345)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -249,13 +249,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=12345)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -359,13 +359,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=12345)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/14_TCP_DST_IPv4.json b/ryu/tests/switch/of13/action/25_SET_FIELD/14_TCP_DST_IPv4.json
index 0f954ef8..a89f8257 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/14_TCP_DST_IPv4.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/14_TCP_DST_IPv4.json
@@ -62,13 +62,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=6789, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=6789, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -137,14 +137,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=6789, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=6789, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -249,13 +249,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=6789, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=6789, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -359,13 +359,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=6789, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=6789, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/14_TCP_DST_IPv6.json b/ryu/tests/switch/of13/action/25_SET_FIELD/14_TCP_DST_IPv6.json
index fc8704ba..d045801c 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/14_TCP_DST_IPv6.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/14_TCP_DST_IPv6.json
@@ -62,13 +62,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=6789, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=6789, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -137,14 +137,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=6789, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=6789, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -249,13 +249,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=6789, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=6789, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -359,13 +359,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=6789, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=6789, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/26_IPV6_SRC.json b/ryu/tests/switch/of13/action/25_SET_FIELD/26_IPV6_SRC.json
index 9f73b0bf..2ae45a91 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/26_IPV6_SRC.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/26_IPV6_SRC.json
@@ -56,13 +56,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='a0::a0', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -125,14 +125,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='a0::a0', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -231,13 +231,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='a0::a0', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -335,13 +335,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='a0::a0', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/27_IPV6_DST.json b/ryu/tests/switch/of13/action/25_SET_FIELD/27_IPV6_DST.json
index 2d5aafda..c2e4cef6 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/27_IPV6_DST.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/27_IPV6_DST.json
@@ -56,13 +56,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -125,14 +125,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -231,13 +231,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -335,13 +335,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/28_IPV6_FLABEL.json b/ryu/tests/switch/of13/action/25_SET_FIELD/28_IPV6_FLABEL.json
index 36aa5452..b77a9ebe 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/28_IPV6_FLABEL.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/28_IPV6_FLABEL.json
@@ -56,13 +56,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=203, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -125,14 +125,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=203, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -231,13 +231,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=203, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -335,13 +335,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=203, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/34_MPLS_LABEL.json b/ryu/tests/switch/of13/action/25_SET_FIELD/34_MPLS_LABEL.json
index c5c5184f..da1bc7ec 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/34_MPLS_LABEL.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/34_MPLS_LABEL.json
@@ -57,14 +57,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -127,14 +127,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/35_MPLS_TC.json b/ryu/tests/switch/of13/action/25_SET_FIELD/35_MPLS_TC.json
index f82dc305..0d564ead 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/35_MPLS_TC.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/35_MPLS_TC.json
@@ -57,14 +57,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=5, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -127,14 +127,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=5, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/36_MPLS_BOS.json b/ryu/tests/switch/of13/action/25_SET_FIELD/36_MPLS_BOS.json
index 344d5a0d..54abdb0e 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/36_MPLS_BOS.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/36_MPLS_BOS.json
@@ -57,14 +57,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=0, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -127,14 +127,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=0, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/37_PBB_ISID.json b/ryu/tests/switch/of13/action/25_SET_FIELD/37_PBB_ISID.json
index 5f680df8..a9bf9c09 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/37_PBB_ISID.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/37_PBB_ISID.json
@@ -61,7 +61,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
@@ -72,7 +72,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -139,7 +139,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
@@ -150,7 +150,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/25_SET_FIELD/38_TUNNEL_ID.json b/ryu/tests/switch/of13/action/25_SET_FIELD/38_TUNNEL_ID.json
index 64e5fcbb..dbefaf13 100644
--- a/ryu/tests/switch/of13/action/25_SET_FIELD/38_TUNNEL_ID.json
+++ b/ryu/tests/switch/of13/action/25_SET_FIELD/38_TUNNEL_ID.json
@@ -81,13 +81,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -174,13 +174,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/26_PUSH_PBB.json b/ryu/tests/switch/of13/action/26_PUSH_PBB.json
index f98ab1b4..0dd4d396 100644
--- a/ryu/tests/switch/of13/action/26_PUSH_PBB.json
+++ b/ryu/tests/switch/of13/action/26_PUSH_PBB.json
@@ -45,7 +45,7 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
@@ -53,7 +53,7 @@
                     "itag()",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -104,7 +104,7 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
@@ -112,7 +112,7 @@
                     "itag()",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/26_PUSH_PBB_multiple.json b/ryu/tests/switch/of13/action/26_PUSH_PBB_multiple.json
index 1a110d09..158f35f6 100644
--- a/ryu/tests/switch/of13/action/26_PUSH_PBB_multiple.json
+++ b/ryu/tests/switch/of13/action/26_PUSH_PBB_multiple.json
@@ -50,7 +50,7 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
@@ -60,7 +60,7 @@
                     "itag()",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -116,7 +116,7 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
@@ -126,7 +126,7 @@
                     "itag()",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/action/27_POP_PBB.json b/ryu/tests/switch/of13/action/27_POP_PBB.json
index d856761b..665e29ed 100644
--- a/ryu/tests/switch/of13/action/27_POP_PBB.json
+++ b/ryu/tests/switch/of13/action/27_POP_PBB.json
@@ -47,7 +47,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
@@ -55,7 +55,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -108,7 +108,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
@@ -116,7 +116,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
diff --git a/ryu/tests/switch/of13/match/00_IN_PORT.json b/ryu/tests/switch/of13/match/00_IN_PORT.json
index 8c277c1f..4d88eebc 100644
--- a/ryu/tests/switch/of13/match/00_IN_PORT.json
+++ b/ryu/tests/switch/of13/match/00_IN_PORT.json
@@ -40,13 +40,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -93,13 +93,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -145,7 +145,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -194,13 +194,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -247,13 +247,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -299,7 +299,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/02_METADATA.json b/ryu/tests/switch/of13/match/02_METADATA.json
index 766b9513..65e00d65 100644
--- a/ryu/tests/switch/of13/match/02_METADATA.json
+++ b/ryu/tests/switch/of13/match/02_METADATA.json
@@ -63,13 +63,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -139,13 +139,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -214,7 +214,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -286,13 +286,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -362,13 +362,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -437,7 +437,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/02_METADATA_Mask.json b/ryu/tests/switch/of13/match/02_METADATA_Mask.json
index 3f6fedeb..59b63aef 100644
--- a/ryu/tests/switch/of13/match/02_METADATA_Mask.json
+++ b/ryu/tests/switch/of13/match/02_METADATA_Mask.json
@@ -64,13 +64,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -141,13 +141,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -217,7 +217,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -290,13 +290,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -367,13 +367,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -443,7 +443,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/03_ETH_DST.json b/ryu/tests/switch/of13/match/03_ETH_DST.json
index 6e898186..52db0c96 100644
--- a/ryu/tests/switch/of13/match/03_ETH_DST.json
+++ b/ryu/tests/switch/of13/match/03_ETH_DST.json
@@ -40,13 +40,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -93,13 +93,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -145,7 +145,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -194,13 +194,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -247,13 +247,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -299,7 +299,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/03_ETH_DST_Mask.json b/ryu/tests/switch/of13/match/03_ETH_DST_Mask.json
index 60f3d93f..8376c16b 100644
--- a/ryu/tests/switch/of13/match/03_ETH_DST_Mask.json
+++ b/ryu/tests/switch/of13/match/03_ETH_DST_Mask.json
@@ -41,13 +41,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -95,13 +95,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -148,7 +148,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -198,13 +198,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -252,13 +252,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -305,7 +305,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/04_ETH_SRC.json b/ryu/tests/switch/of13/match/04_ETH_SRC.json
index 7cfda44e..29fb2c93 100644
--- a/ryu/tests/switch/of13/match/04_ETH_SRC.json
+++ b/ryu/tests/switch/of13/match/04_ETH_SRC.json
@@ -40,13 +40,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -93,13 +93,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -145,7 +145,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -194,13 +194,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -247,13 +247,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -299,7 +299,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/04_ETH_SRC_Mask.json b/ryu/tests/switch/of13/match/04_ETH_SRC_Mask.json
index d6e4847c..4f4f94b5 100644
--- a/ryu/tests/switch/of13/match/04_ETH_SRC_Mask.json
+++ b/ryu/tests/switch/of13/match/04_ETH_SRC_Mask.json
@@ -41,13 +41,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -95,13 +95,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -148,7 +148,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -198,13 +198,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -252,13 +252,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -305,7 +305,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/05_ETH_TYPE.json b/ryu/tests/switch/of13/match/05_ETH_TYPE.json
index 9013b143..8adbd702 100644
--- a/ryu/tests/switch/of13/match/05_ETH_TYPE.json
+++ b/ryu/tests/switch/of13/match/05_ETH_TYPE.json
@@ -40,13 +40,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -93,13 +93,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -145,7 +145,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -194,13 +194,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -247,13 +247,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -299,7 +299,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/06_VLAN_VID.json b/ryu/tests/switch/of13/match/06_VLAN_VID.json
index 5ef10282..44daf01c 100644
--- a/ryu/tests/switch/of13/match/06_VLAN_VID.json
+++ b/ryu/tests/switch/of13/match/06_VLAN_VID.json
@@ -41,14 +41,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -96,14 +96,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -150,7 +150,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -200,14 +200,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -255,14 +255,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -309,7 +309,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/06_VLAN_VID_Mask.json b/ryu/tests/switch/of13/match/06_VLAN_VID_Mask.json
index 193afc7d..e1a5b0b3 100644
--- a/ryu/tests/switch/of13/match/06_VLAN_VID_Mask.json
+++ b/ryu/tests/switch/of13/match/06_VLAN_VID_Mask.json
@@ -42,14 +42,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -98,14 +98,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -153,7 +153,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -204,14 +204,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -260,14 +260,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -315,7 +315,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/07_VLAN_PCP.json b/ryu/tests/switch/of13/match/07_VLAN_PCP.json
index 3cf79de0..2c2ea24a 100644
--- a/ryu/tests/switch/of13/match/07_VLAN_PCP.json
+++ b/ryu/tests/switch/of13/match/07_VLAN_PCP.json
@@ -48,14 +48,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -110,14 +110,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -171,7 +171,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -228,14 +228,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -290,14 +290,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -351,7 +351,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/08_IP_DSCP_IPv4.json b/ryu/tests/switch/of13/match/08_IP_DSCP_IPv4.json
index fcb5770f..019f1b43 100644
--- a/ryu/tests/switch/of13/match/08_IP_DSCP_IPv4.json
+++ b/ryu/tests/switch/of13/match/08_IP_DSCP_IPv4.json
@@ -46,13 +46,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -105,13 +105,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -163,7 +163,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -219,14 +219,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -280,14 +280,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -340,7 +340,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -432,13 +432,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -528,13 +528,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -623,7 +623,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -714,13 +714,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -809,13 +809,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -903,7 +903,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/08_IP_DSCP_IPv6.json b/ryu/tests/switch/of13/match/08_IP_DSCP_IPv6.json
index 65a120f8..b4273dc0 100644
--- a/ryu/tests/switch/of13/match/08_IP_DSCP_IPv6.json
+++ b/ryu/tests/switch/of13/match/08_IP_DSCP_IPv6.json
@@ -46,13 +46,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -105,13 +105,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -163,7 +163,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -219,14 +219,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -280,14 +280,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -340,7 +340,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -432,13 +432,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -528,13 +528,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -623,7 +623,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -714,13 +714,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -809,13 +809,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -903,7 +903,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/09_IP_ECN_IPv4.json b/ryu/tests/switch/of13/match/09_IP_ECN_IPv4.json
index 03f10f8d..f1a9cddf 100644
--- a/ryu/tests/switch/of13/match/09_IP_ECN_IPv4.json
+++ b/ryu/tests/switch/of13/match/09_IP_ECN_IPv4.json
@@ -47,13 +47,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -106,13 +106,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -164,7 +164,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -220,14 +220,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -281,14 +281,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -341,7 +341,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -433,13 +433,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -529,13 +529,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -624,7 +624,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -715,13 +715,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -810,13 +810,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -904,7 +904,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/09_IP_ECN_IPv6.json b/ryu/tests/switch/of13/match/09_IP_ECN_IPv6.json
index 694457cb..c32c3cb4 100644
--- a/ryu/tests/switch/of13/match/09_IP_ECN_IPv6.json
+++ b/ryu/tests/switch/of13/match/09_IP_ECN_IPv6.json
@@ -46,13 +46,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -105,13 +105,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -163,7 +163,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -219,14 +219,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -280,14 +280,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -340,7 +340,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -432,13 +432,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -528,13 +528,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -623,7 +623,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -714,13 +714,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -809,13 +809,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -903,7 +903,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/10_IP_PROTO_IPv4.json b/ryu/tests/switch/of13/match/10_IP_PROTO_IPv4.json
index c64f6527..f3cc41e1 100644
--- a/ryu/tests/switch/of13/match/10_IP_PROTO_IPv4.json
+++ b/ryu/tests/switch/of13/match/10_IP_PROTO_IPv4.json
@@ -46,13 +46,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -105,13 +105,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -163,7 +163,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -219,14 +219,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -280,14 +280,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -340,7 +340,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -432,13 +432,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -528,13 +528,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -623,7 +623,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -714,13 +714,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -809,13 +809,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -903,7 +903,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/10_IP_PROTO_IPv6.json b/ryu/tests/switch/of13/match/10_IP_PROTO_IPv6.json
index f3013263..de93cd09 100644
--- a/ryu/tests/switch/of13/match/10_IP_PROTO_IPv6.json
+++ b/ryu/tests/switch/of13/match/10_IP_PROTO_IPv6.json
@@ -46,13 +46,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -105,13 +105,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -163,7 +163,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -219,14 +219,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -280,14 +280,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -340,7 +340,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -432,13 +432,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -528,13 +528,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -623,7 +623,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -714,13 +714,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -809,13 +809,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -903,7 +903,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/11_IPV4_SRC.json b/ryu/tests/switch/of13/match/11_IPV4_SRC.json
index f1c528fe..dd9798cf 100644
--- a/ryu/tests/switch/of13/match/11_IPV4_SRC.json
+++ b/ryu/tests/switch/of13/match/11_IPV4_SRC.json
@@ -46,13 +46,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -105,13 +105,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -163,7 +163,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -219,14 +219,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -280,14 +280,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -340,7 +340,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -432,13 +432,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -528,13 +528,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -623,7 +623,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -714,13 +714,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -809,13 +809,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -903,7 +903,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/11_IPV4_SRC_Mask.json b/ryu/tests/switch/of13/match/11_IPV4_SRC_Mask.json
index b5d11dad..48ce171d 100644
--- a/ryu/tests/switch/of13/match/11_IPV4_SRC_Mask.json
+++ b/ryu/tests/switch/of13/match/11_IPV4_SRC_Mask.json
@@ -47,13 +47,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -107,13 +107,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -166,7 +166,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -223,14 +223,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -285,14 +285,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -346,7 +346,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -439,13 +439,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -536,13 +536,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -632,7 +632,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -724,13 +724,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -820,13 +820,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -915,7 +915,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/12_IPV4_DST.json b/ryu/tests/switch/of13/match/12_IPV4_DST.json
index 70b9dbfb..e976ae52 100644
--- a/ryu/tests/switch/of13/match/12_IPV4_DST.json
+++ b/ryu/tests/switch/of13/match/12_IPV4_DST.json
@@ -46,13 +46,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -105,13 +105,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -163,7 +163,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -219,14 +219,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -280,14 +280,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -340,7 +340,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -432,13 +432,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -528,13 +528,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -623,7 +623,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -714,13 +714,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -809,13 +809,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -903,7 +903,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/12_IPV4_DST_Mask.json b/ryu/tests/switch/of13/match/12_IPV4_DST_Mask.json
index 696786fb..61fa1c6c 100644
--- a/ryu/tests/switch/of13/match/12_IPV4_DST_Mask.json
+++ b/ryu/tests/switch/of13/match/12_IPV4_DST_Mask.json
@@ -48,13 +48,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -108,13 +108,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -167,7 +167,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -224,14 +224,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -286,14 +286,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -347,7 +347,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -440,13 +440,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -537,13 +537,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -633,7 +633,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -725,13 +725,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -821,13 +821,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -916,7 +916,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/13_TCP_SRC_IPv4.json b/ryu/tests/switch/of13/match/13_TCP_SRC_IPv4.json
index 7527c29a..4654a03d 100644
--- a/ryu/tests/switch/of13/match/13_TCP_SRC_IPv4.json
+++ b/ryu/tests/switch/of13/match/13_TCP_SRC_IPv4.json
@@ -52,13 +52,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -117,13 +117,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -181,7 +181,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -243,14 +243,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -310,14 +310,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -376,7 +376,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -474,13 +474,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -576,13 +576,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -677,7 +677,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -774,13 +774,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -875,13 +875,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -975,7 +975,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/13_TCP_SRC_IPv6.json b/ryu/tests/switch/of13/match/13_TCP_SRC_IPv6.json
index b7fa7d28..1615f8c0 100644
--- a/ryu/tests/switch/of13/match/13_TCP_SRC_IPv6.json
+++ b/ryu/tests/switch/of13/match/13_TCP_SRC_IPv6.json
@@ -52,13 +52,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -117,13 +117,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -181,7 +181,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -243,14 +243,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -310,14 +310,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -376,7 +376,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -474,13 +474,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -576,13 +576,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -677,7 +677,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -774,13 +774,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -875,13 +875,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -975,7 +975,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/14_TCP_DST_IPv4.json b/ryu/tests/switch/of13/match/14_TCP_DST_IPv4.json
index 25e8f384..7e0d09a7 100644
--- a/ryu/tests/switch/of13/match/14_TCP_DST_IPv4.json
+++ b/ryu/tests/switch/of13/match/14_TCP_DST_IPv4.json
@@ -52,13 +52,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -117,13 +117,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -181,7 +181,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -243,14 +243,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -310,14 +310,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -376,7 +376,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -474,13 +474,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -576,13 +576,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -677,7 +677,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -774,13 +774,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -875,13 +875,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -975,7 +975,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/14_TCP_DST_IPv6.json b/ryu/tests/switch/of13/match/14_TCP_DST_IPv6.json
index 0f4f6a96..8f85f967 100644
--- a/ryu/tests/switch/of13/match/14_TCP_DST_IPv6.json
+++ b/ryu/tests/switch/of13/match/14_TCP_DST_IPv6.json
@@ -52,13 +52,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -117,13 +117,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -181,7 +181,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -243,14 +243,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -310,14 +310,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -376,7 +376,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -474,13 +474,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -576,13 +576,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -677,7 +677,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -774,13 +774,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -875,13 +875,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -975,7 +975,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/26_IPV6_SRC.json b/ryu/tests/switch/of13/match/26_IPV6_SRC.json
index c68c77e2..9ffc94e7 100644
--- a/ryu/tests/switch/of13/match/26_IPV6_SRC.json
+++ b/ryu/tests/switch/of13/match/26_IPV6_SRC.json
@@ -46,13 +46,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -105,13 +105,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -163,7 +163,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -219,14 +219,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -280,14 +280,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -340,7 +340,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -432,13 +432,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -528,13 +528,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -623,7 +623,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -714,13 +714,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -809,13 +809,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -903,7 +903,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/26_IPV6_SRC_Mask.json b/ryu/tests/switch/of13/match/26_IPV6_SRC_Mask.json
index 46b0a0de..3d3df8ac 100644
--- a/ryu/tests/switch/of13/match/26_IPV6_SRC_Mask.json
+++ b/ryu/tests/switch/of13/match/26_IPV6_SRC_Mask.json
@@ -47,13 +47,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -107,13 +107,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -166,7 +166,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -223,14 +223,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -285,14 +285,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -346,7 +346,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -439,13 +439,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -536,13 +536,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -632,7 +632,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -724,13 +724,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -820,13 +820,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -915,7 +915,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/27_IPV6_DST.json b/ryu/tests/switch/of13/match/27_IPV6_DST.json
index cd2fd1cc..05a087f3 100644
--- a/ryu/tests/switch/of13/match/27_IPV6_DST.json
+++ b/ryu/tests/switch/of13/match/27_IPV6_DST.json
@@ -46,13 +46,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -105,13 +105,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -163,7 +163,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -219,14 +219,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -280,14 +280,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -340,7 +340,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -432,13 +432,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -528,13 +528,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -623,7 +623,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -714,13 +714,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -809,13 +809,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -903,7 +903,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/27_IPV6_DST_Mask.json b/ryu/tests/switch/of13/match/27_IPV6_DST_Mask.json
index cceea8ee..53f43f09 100644
--- a/ryu/tests/switch/of13/match/27_IPV6_DST_Mask.json
+++ b/ryu/tests/switch/of13/match/27_IPV6_DST_Mask.json
@@ -47,13 +47,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -107,13 +107,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -166,7 +166,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -223,14 +223,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -285,14 +285,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -346,7 +346,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -439,13 +439,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -536,13 +536,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -632,7 +632,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -724,13 +724,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -820,13 +820,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -915,7 +915,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/28_IPV6_FLABEL.json b/ryu/tests/switch/of13/match/28_IPV6_FLABEL.json
index 7999e750..13481342 100644
--- a/ryu/tests/switch/of13/match/28_IPV6_FLABEL.json
+++ b/ryu/tests/switch/of13/match/28_IPV6_FLABEL.json
@@ -46,13 +46,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -105,13 +105,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -163,7 +163,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -219,14 +219,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -280,14 +280,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -340,7 +340,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -432,13 +432,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -528,13 +528,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -623,7 +623,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -714,13 +714,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -809,13 +809,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -903,7 +903,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/34_MPLS_LABEL.json b/ryu/tests/switch/of13/match/34_MPLS_LABEL.json
index ee58c4f3..34bc8356 100644
--- a/ryu/tests/switch/of13/match/34_MPLS_LABEL.json
+++ b/ryu/tests/switch/of13/match/34_MPLS_LABEL.json
@@ -47,14 +47,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -108,14 +108,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -168,7 +168,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -224,14 +224,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -285,14 +285,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -345,7 +345,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/35_MPLS_TC.json b/ryu/tests/switch/of13/match/35_MPLS_TC.json
index 6cf4e214..df239c9b 100644
--- a/ryu/tests/switch/of13/match/35_MPLS_TC.json
+++ b/ryu/tests/switch/of13/match/35_MPLS_TC.json
@@ -47,14 +47,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -108,14 +108,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -168,7 +168,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -224,14 +224,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -285,14 +285,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -345,7 +345,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/36_MPLS_BOS.json b/ryu/tests/switch/of13/match/36_MPLS_BOS.json
index 123d22d6..997e7be6 100644
--- a/ryu/tests/switch/of13/match/36_MPLS_BOS.json
+++ b/ryu/tests/switch/of13/match/36_MPLS_BOS.json
@@ -47,14 +47,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -108,14 +108,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -169,7 +169,7 @@
                     "mpls(bsb=0, label=203, exp=5, ttl=127)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -225,14 +225,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -286,14 +286,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -347,7 +347,7 @@
                     "mpls(bsb=0, label=203, exp=5, ttl=127)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/37_PBB_ISID.json b/ryu/tests/switch/of13/match/37_PBB_ISID.json
index de345d10..015c8e3e 100644
--- a/ryu/tests/switch/of13/match/37_PBB_ISID.json
+++ b/ryu/tests/switch/of13/match/37_PBB_ISID.json
@@ -51,7 +51,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
@@ -62,7 +62,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -120,7 +120,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
@@ -131,7 +131,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -188,7 +188,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -248,7 +248,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
@@ -259,7 +259,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -317,7 +317,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
@@ -328,7 +328,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -385,7 +385,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/37_PBB_ISID_Mask.json b/ryu/tests/switch/of13/match/37_PBB_ISID_Mask.json
index c8d8f151..a855f5a9 100644
--- a/ryu/tests/switch/of13/match/37_PBB_ISID_Mask.json
+++ b/ryu/tests/switch/of13/match/37_PBB_ISID_Mask.json
@@ -52,7 +52,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
@@ -63,7 +63,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -122,7 +122,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
@@ -133,7 +133,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -191,7 +191,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=2048)",
                     "ipv4(tos=65, proto=6, src='10.10.10.10', dst='10.10.20.20', ttl=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -252,7 +252,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
@@ -263,7 +263,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -322,7 +322,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
@@ -333,7 +333,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -391,7 +391,7 @@
                     "svlan(ethertype=33024, vid=10)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127, traffic_class=65)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/38_TUNNEL_ID.json b/ryu/tests/switch/of13/match/38_TUNNEL_ID.json
index 1460a300..86d3f623 100644
--- a/ryu/tests/switch/of13/match/38_TUNNEL_ID.json
+++ b/ryu/tests/switch/of13/match/38_TUNNEL_ID.json
@@ -81,13 +81,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -175,13 +175,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -268,7 +268,7 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -358,13 +358,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -452,13 +452,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -545,7 +545,7 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/38_TUNNEL_ID_Mask.json b/ryu/tests/switch/of13/match/38_TUNNEL_ID_Mask.json
index 161be1b7..b7e91c6c 100644
--- a/ryu/tests/switch/of13/match/38_TUNNEL_ID_Mask.json
+++ b/ryu/tests/switch/of13/match/38_TUNNEL_ID_Mask.json
@@ -82,13 +82,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -177,13 +177,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -271,7 +271,7 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=2048)",
                     "ipv4(tos=32, proto=6, src='192.168.10.10', dst='192.168.20.20', ttl=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -362,13 +362,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -457,13 +457,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -551,7 +551,7 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20', flow_label=100, src='10::10', nxt=6, hop_limit=64, traffic_class=32)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/39_IPV6_EXTHDR.json b/ryu/tests/switch/of13/match/39_IPV6_EXTHDR.json
index 44360b10..a65c6f2b 100644
--- a/ryu/tests/switch/of13/match/39_IPV6_EXTHDR.json
+++ b/ryu/tests/switch/of13/match/39_IPV6_EXTHDR.json
@@ -46,13 +46,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -105,13 +105,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -163,7 +163,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -219,14 +219,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -280,14 +280,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -340,7 +340,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -432,13 +432,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -528,13 +528,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -623,7 +623,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -714,13 +714,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -809,13 +809,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -903,7 +903,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
diff --git a/ryu/tests/switch/of13/match/39_IPV6_EXTHDR_Mask.json b/ryu/tests/switch/of13/match/39_IPV6_EXTHDR_Mask.json
index 636bd6ff..e4d48fb1 100644
--- a/ryu/tests/switch/of13/match/39_IPV6_EXTHDR_Mask.json
+++ b/ryu/tests/switch/of13/match/39_IPV6_EXTHDR_Mask.json
@@ -47,13 +47,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -107,13 +107,13 @@
                 "ingress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -166,7 +166,7 @@
                 "ingress":[
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -223,14 +223,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -285,14 +285,14 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=33024)",
                     "vlan(pcp=3, cfi=0, vid=100, ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -346,7 +346,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=33024)",
                     "vlan(pcp=5, cfi=0, vid=203, ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -439,13 +439,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -536,13 +536,13 @@
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34887)",
                     "mpls(bsb=1, label=100, exp=3, ttl=64)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -632,7 +632,7 @@
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34887)",
                     "mpls(bsb=1, label=203, exp=5, ttl=127)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[
@@ -724,13 +724,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "egress":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -820,13 +820,13 @@
                     "itag(sid=100)",
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "PACKET_IN":[
                     "ethernet(dst='22:22:22:22:22:22', src='12:11:11:11:11:11', ethertype=34525)",
                     "ipv6(dst='20::20',ext_hdrs=[hop_opts(nxt=51), auth(nxt=6)],flow_label=100, src='10::10', nxt=0, hop_limit=64)",
-                    "tcp(dst_port=2222, option='\\x00\\x00\\x00\\x00', src_port=11111)",
+                    "tcp(dst_port=2222, option=str('\\x00' * 4), src_port=11111)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ]
             }
@@ -915,7 +915,7 @@
                     "itag(sid=203)",
                     "ethernet(dst='ba:bb:bb:bb:bb:bb', src='aa:aa:aa:aa:aa:aa', ethertype=34525)",
                     "ipv6(dst='b0::b0', flow_label=203, src='a0::a0', nxt=6, hop_limit=127)",
-                    "tcp(dst_port=6789, option='\\x11\\x11\\x11\\x11', src_port=12345)",
+                    "tcp(dst_port=6789, option=str('\\x11' * 4), src_port=12345)",
                     "'\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f'"
                 ],
                 "table-miss":[