Use new(er)-style string formatting, {} instead of {0}

13 files changed, 28 insertions, 28 deletions

diff --git a/paramiko/auth_handler.py b/paramiko/auth_handler.py
index d2dab3d8..b6d07f65 100644
--- a/paramiko/auth_handler.py
+++ b/paramiko/auth_handler.py
@@ -475,7 +475,7 @@ class AuthHandler (object):
                     'Auth rejected: public key: %s' % str(e))
                 key = None
             except Exception as e:
-                msg = 'Auth rejected: unsupported or mangled public key ({0}: {1})' # noqa
+                msg = 'Auth rejected: unsupported or mangled public key ({}: {})' # noqa
                 self.transport._log(INFO, msg.format(e.__class__.__name__, e))
                 key = None
             if key is None:
diff --git a/paramiko/channel.py b/paramiko/channel.py
index c6016a0e..f3572c66 100644
--- a/paramiko/channel.py
+++ b/paramiko/channel.py
@@ -315,7 +315,7 @@ class Channel (ClosingContextManager):
             try:
                 self.set_environment_variable(name, value)
             except SSHException as e:
-                err = "Failed to set environment variable \"{0}\"."
+                err = "Failed to set environment variable \"{}\"."
                 raise SSHException(err.format(name), e)
 
     @open_only
diff --git a/paramiko/client.py b/paramiko/client.py
index 75d295ea..e5931d09 100644
--- a/paramiko/client.py
+++ b/paramiko/client.py
@@ -544,14 +544,14 @@ class SSHClient (ClosingContextManager):
         # TODO: change this to 'Loading' instead of 'Trying' sometime; probably
         # when #387 is released, since this is a critical log message users are
         # likely testing/filtering for (bah.)
-        msg = "Trying discovered key {0} in {1}".format(
+        msg = "Trying discovered key {} in {}".format(
             hexlify(key.get_fingerprint()), key_path,
         )
         self._log(DEBUG, msg)
         # Attempt to load cert if it exists.
         if os.path.isfile(cert_path):
             key.load_certificate(cert_path)
-            self._log(DEBUG, "Adding public certificate {0}".format(cert_path))
+            self._log(DEBUG, "Adding public certificate {}".format(cert_path))
         return key
 
     def _auth(self, username, password, pkey, key_filenames, allow_agent,
diff --git a/paramiko/ecdsakey.py b/paramiko/ecdsakey.py
index 1bb5676f..819e1d6a 100644
--- a/paramiko/ecdsakey.py
+++ b/paramiko/ecdsakey.py
@@ -134,7 +134,7 @@ class ECDSAKey(PKey):
             )
             key_types = self._ECDSA_CURVES.get_key_format_identifier_list()
             cert_types = [
-                '{0}-cert-v01@openssh.com'.format(x)
+                '{}-cert-v01@openssh.com'.format(x)
                 for x in key_types
             ]
             self._check_type_and_load_cert(
diff --git a/paramiko/pkey.py b/paramiko/pkey.py
index 67723be2..533d0797 100644
--- a/paramiko/pkey.py
+++ b/paramiko/pkey.py
@@ -409,7 +409,7 @@ class PKey(object):
             # (requires going back into per-type subclasses.)
             msg.get_string()
         else:
-            err = 'Invalid key (class: {0}, data type: {1}'
+            err = 'Invalid key (class: {}, data type: {}'
             raise SSHException(err.format(self.__class__.__name__, type_))
 
     def load_certificate(self, value):
@@ -439,7 +439,7 @@ class PKey(object):
             constructor = 'from_string'
         blob = getattr(PublicBlob, constructor)(value)
         if not blob.key_type.startswith(self.get_name()):
-            err = "PublicBlob type {0} incompatible with key type {1}"
+            err = "PublicBlob type {} incompatible with key type {}"
             raise ValueError(err.format(blob.key_type, self.get_name()))
         self.public_blob = blob
 
@@ -490,7 +490,7 @@ class PublicBlob(object):
         """
         fields = string.split(None, 2)
         if len(fields) < 2:
-            msg = "Not enough fields for public blob: {0}"
+            msg = "Not enough fields for public blob: {}"
             raise ValueError(msg.format(fields))
         key_type = fields[0]
         key_blob = decodebytes(b(fields[1]))
@@ -503,7 +503,7 @@ class PublicBlob(object):
         m = Message(key_blob)
         blob_type = m.get_text()
         if blob_type != key_type:
-            msg = "Invalid PublicBlob contents: key type={0!r}, but blob type={1!r}" # noqa
+            msg = "Invalid PublicBlob contents: key type={!r}, but blob type={!r}" # noqa
             raise ValueError(msg.format(key_type, blob_type))
         # All good? All good.
         return cls(type_=key_type, blob=key_blob, comment=comment)
@@ -520,9 +520,9 @@ class PublicBlob(object):
         return cls(type_=type_, blob=message.asbytes())
 
     def __str__(self):
-        ret = '{0} public key/certificate'.format(self.key_type)
+        ret = '{} public key/certificate'.format(self.key_type)
         if self.comment:
-            ret += "- {0}".format(self.comment)
+            ret += "- {}".format(self.comment)
         return ret
 
     def __eq__(self, other):
diff --git a/paramiko/server.py b/paramiko/server.py
index c96126e9..1f96451e 100644
--- a/paramiko/server.py
+++ b/paramiko/server.py
@@ -672,7 +672,7 @@ class SubsystemHandler (threading.Thread):
         except Exception as e:
             self.__transport._log(
                 ERROR,
-                'Exception in subsystem handler for "{0}": {1}'.format(
+                'Exception in subsystem handler for "{}": {}'.format(
                     self.__name, e
                 )
             )
diff --git a/paramiko/sftp_server.py b/paramiko/sftp_server.py
index f7d1c657..103081dd 100644
--- a/paramiko/sftp_server.py
+++ b/paramiko/sftp_server.py
@@ -200,7 +200,7 @@ class SFTPServer (BaseSFTP, SubsystemHandler):
                 item._pack(msg)
             else:
                 raise Exception(
-                    'unknown type for {0!r} type {1!r}'.format(
+                    'unknown type for {!r} type {!r}'.format(
                         item, type(item)))
         self._send_packet(t, msg)
 
diff --git a/paramiko/ssh_exception.py b/paramiko/ssh_exception.py
index e9ab8d66..f8405a31 100644
--- a/paramiko/ssh_exception.py
+++ b/paramiko/ssh_exception.py
@@ -63,7 +63,7 @@ class BadAuthenticationType (AuthenticationException):
         self.args = (explanation, types, )
 
     def __str__(self):
-        return '{0} (allowed_types={1!r})'.format(
+        return '{} (allowed_types={!r})'.format(
             SSHException.__str__(self), self.allowed_types
         )
 
@@ -107,7 +107,7 @@ class BadHostKeyException (SSHException):
     .. versionadded:: 1.6
     """
     def __init__(self, hostname, got_key, expected_key):
-        message = 'Host key for server {0} does not match: got {1}, expected {2}' # noqa
+        message = 'Host key for server {} does not match: got {}, expected {}' # noqa
         message = message.format(
             hostname, got_key.get_base64(),
             expected_key.get_base64())
diff --git a/paramiko/ssh_gss.py b/paramiko/ssh_gss.py
index 4d9aaa55..88dedf7e 100644
--- a/paramiko/ssh_gss.py
+++ b/paramiko/ssh_gss.py
@@ -284,7 +284,7 @@ class _SSH_GSSAPI(_SSH_GSSAuth):
             else:
                 token = self._gss_ctxt.step(recv_token)
         except gssapi.GSSException:
-            message = "{0} Target: {1}".format(
+            message = "{} Target: {}".format(
                 sys.exc_info()[1], self._gss_host)
             raise gssapi.GSSException(message)
         self._gss_ctxt_status = self._gss_ctxt.established
diff --git a/paramiko/transport.py b/paramiko/transport.py
index 9df34caf..544ecf0f 100644
--- a/paramiko/transport.py
+++ b/paramiko/transport.py
@@ -1965,11 +1965,11 @@ class Transport(threading.Thread, ClosingContextManager):
         # Log useful, non-duplicative line re: an agreed-upon algorithm.
         # Old code implied algorithms could be asymmetrical (different for
         # inbound vs outbound) so we preserve that possibility.
-        msg = "{0} agreed: ".format(which)
+        msg = "{} agreed: ".format(which)
         if local == remote:
             msg += local
         else:
-            msg += "local={0}, remote={1}".format(local, remote)
+            msg += "local={}, remote={}".format(local, remote)
         self._log(DEBUG, msg)
 
     # protocol stages
@@ -2025,9 +2025,9 @@ class Transport(threading.Thread, ClosingContextManager):
         version = segs[1]
         client = segs[2]
         if version != '1.99' and version != '2.0':
-            msg = 'Incompatible version ({0} instead of 2.0)'
+            msg = 'Incompatible version ({} instead of 2.0)'
             raise SSHException(msg.format(version))
-        msg = 'Connected (version {0}, client {1})'.format(version, client)
+        msg = 'Connected (version {}, client {})'.format(version, client)
         self._log(INFO, msg)
 
     def _send_kex_init(self):
@@ -2223,7 +2223,7 @@ class Transport(threading.Thread, ClosingContextManager):
             len(agreed_local_compression) == 0 or
             len(agreed_remote_compression) == 0
         ):
-            msg = 'Incompatible ssh server (no acceptable compression) {0!r} {1!r} {2!r}' # noqa
+            msg = 'Incompatible ssh server (no acceptable compression) {!r} {!r} {!r}' # noqa
             raise SSHException(msg.format(
                 agreed_local_compression, agreed_remote_compression,
                 self._preferred_compression,
@@ -2583,7 +2583,7 @@ class Transport(threading.Thread, ClosingContextManager):
         m.get_boolean()  # always_display
         msg = m.get_string()
         m.get_string()  # language
-        self._log(DEBUG, 'Debug msg: {0}'.format(util.safe_string(msg)))
+        self._log(DEBUG, 'Debug msg: {}'.format(util.safe_string(msg)))
 
     def _get_subsystem_handler(self, name):
         try:
diff --git a/tasks.py b/tasks.py
index 4ddeeee3..a45b4efc 100644
--- a/tasks.py
+++ b/tasks.py
@@ -21,7 +21,7 @@ def test(ctx, coverage=False, flags=""):
     env = dict(os.environ)
     if 'SSH_AUTH_SOCK' in env:
         del env['SSH_AUTH_SOCK']
-    cmd = "{0} test.py {1}".format(runner, flags)
+    cmd = "{} test.py {}".format(runner, flags)
     ctx.run(cmd, pty=True, env=env, replace_env=True)
 
 
diff --git a/tests/test_client.py b/tests/test_client.py
index 7058f394..21b00b68 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -238,7 +238,7 @@ class SSHClientTest (unittest.TestCase):
             try:
                 self._test_connection(
                     key_filename=[
-                        test_path('test_{0}.key'.format(x)) for x in attempt
+                        test_path('test_{}.key'.format(x)) for x in attempt
                     ],
                     allowed_keys=[types_[x] for x in accept],
                 )
@@ -266,7 +266,7 @@ class SSHClientTest (unittest.TestCase):
         # server-side behavior is 100% identical.)
         # NOTE: only bothered whipping up one cert per overall class/family.
         for type_ in ('rsa', 'dss', 'ecdsa_256', 'ed25519'):
-            cert_name = 'test_{0}.key-cert.pub'.format(type_)
+            cert_name = 'test_{}.key-cert.pub'.format(type_)
             cert_path = test_path(os.path.join('cert_support', cert_name))
             self._test_connection(
                 key_filename=cert_path,
@@ -281,12 +281,12 @@ class SSHClientTest (unittest.TestCase):
         # that a specific cert was found, along with regular authorization
         # succeeding proving that the overall flow works.
         for type_ in ('rsa', 'dss', 'ecdsa_256', 'ed25519'):
-            key_name = 'test_{0}.key'.format(type_)
+            key_name = 'test_{}.key'.format(type_)
             key_path = test_path(os.path.join('cert_support', key_name))
             self._test_connection(
                 key_filename=key_path,
                 public_blob=PublicBlob.from_file(
-                    '{0}-cert.pub'.format(key_path)
+                    '{}-cert.pub'.format(key_path)
                 ),
             )
 
diff --git a/tests/test_util.py b/tests/test_util.py
index 7880e156..633c3345 100644
--- a/tests/test_util.py
+++ b/tests/test_util.py
@@ -474,7 +474,7 @@ Host param3 parara
         safe_vanilla = safe_string(vanilla)
         safe_has_bytes = safe_string(has_bytes)
         expected_bytes = b("has %07%03 bytes")
-        err = "{0!r} != {1!r}"
+        err = "{!r} != {!r}"
         msg = err.format(safe_vanilla, vanilla)
         assert safe_vanilla == vanilla, msg
         msg = err.format(safe_has_bytes, expected_bytes)