don't abuse __dict__ attribute

There are built-in functions to handle attribute like hasattr.
Use standard functions instead of abusing __dict__.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

3 files changed, 9 insertions, 12 deletions

diff --git a/ryu/base/app_manager.py b/ryu/base/app_manager.py
index 5a35a6e6..4a29c95d 100644
--- a/ryu/base/app_manager.py
+++ b/ryu/base/app_manager.py
@@ -14,6 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import inspect
 import itertools
 import logging
 
@@ -72,12 +73,10 @@ class AppManager(object):
 
     def load_app(self, name):
         mod = utils.import_module(name)
-        for k, v in mod.__dict__.items():
-            try:
-                if issubclass(v, RyuApp):
-                    return getattr(mod, k)
-            except TypeError:
-                pass
+        clses = inspect.getmembers(mod, lambda cls: (inspect.isclass(cls) and
+                                                     issubclass(cls, RyuApp)))
+        if clses:
+            return clses[0][1]
         return None
 
     def load_apps(self, app_lists):
@@ -113,7 +112,7 @@ class AppManager(object):
             # Yes, maybe for slicing.
             LOG.info('instantiating app %s', app_name)
 
-            if 'OFP_VERSIONS' in cls.__dict__:
+            if hasattr(cls, 'OFP_VERSIONS'):
                 for k in Datapath.supported_ofp_version.keys():
                     if not k in cls.OFP_VERSIONS:
                         del Datapath.supported_ofp_version[k]
diff --git a/ryu/controller/handler.py b/ryu/controller/handler.py
index 4566cd5a..ede27df0 100644
--- a/ryu/controller/handler.py
+++ b/ryu/controller/handler.py
@@ -44,7 +44,7 @@ def set_ev_cls(ev_cls, dispatchers):
 
 
 def _is_ev_handler(meth):
-    return 'ev_cls' in meth.__dict__
+    return hasattr(meth, 'ev_cls')
 
 
 def _listify(may_list):
diff --git a/ryu/controller/ofp_event.py b/ryu/controller/ofp_event.py
index ed9f1b38..e5becac0 100644
--- a/ryu/controller/ofp_event.py
+++ b/ryu/controller/ofp_event.py
@@ -59,10 +59,8 @@ def _create_ofp_msg_ev_class(msg_cls):
 def _create_ofp_msg_ev_from_module(modname):
     mod = utils.import_module(modname)
     # print mod
-    for _k, cls in mod.__dict__.items():
-        if not inspect.isclass(cls):
-            continue
-        if 'cls_msg_type' not in cls.__dict__:
+    for _k, cls in inspect.getmembers(mod, inspect.isclass):
+        if not hasattr(cls, 'cls_msg_type'):
             continue
         _create_ofp_msg_ev_class(cls)