Adopt reviewer's suggestion

src/python/grpcio/grpc/__init__.py

@@ -1746,21 +1746,29 @@ def dynamic_ssl_server_credentials(initial_certificate_configuration,
 
 @enum.unique
 class LocalConnectionType(enum.Enum):
-    """Type of local connections for which local channel/server credentials will be applied.
+    """Types of local connection for local credential creation.
 
     Attributes:
       UDS: Unix domain socket connections
       LOCAL_TCP: Local TCP connections.
     """
-    UDS = _cygrpc.LocalConnectType.uds
-    LOCAL_TCP = _cygrpc.LocalConnectType.local_tcp
+    UDS = _cygrpc.LocalConnectionType.uds
+    LOCAL_TCP = _cygrpc.LocalConnectionType.local_tcp
 
 
 def local_channel_credentials(local_connect_type=LocalConnectionType.LOCAL_TCP):
     """Creates a local ChannelCredentials used for local connections.
 
+    Local credentials are used by local TCP endpoints (e.g. localhost:10000)
+    also UDS connections. It allows them to create secure channel, hence
+    transmitting call credentials become possible.
+
+    It is useful for 1) eliminating insecure_channel usage; 2) enable unit
+    testing for call credentials without setting up secrets.
+
     Args:
-      local_connect_type: Local connection type (either UDS or LOCAL_TCP)
+      local_connect_type: Local connection type (either
+        grpc.LocalConnectionType.UDS or grpc.LocalConnectionType.LOCAL_TCP)
 
     Returns:
       A ChannelCredentials for use with a local Channel
@@ -1772,8 +1780,16 @@ def local_channel_credentials(local_connect_type=LocalConnectionType.LOCAL_TCP):
 def local_server_credentials(local_connect_type=LocalConnectionType.LOCAL_TCP):
     """Creates a local ServerCredentials used for local connections.
 
+    Local credentials are used by local TCP endpoints (e.g. localhost:10000)
+    also UDS connections. It allows them to create secure channel, hence
+    transmitting call credentials become possible.
+
+    It is useful for 1) eliminating insecure_channel usage; 2) enable unit
+    testing for call credentials without setting up secrets.
+
     Args:
-      local_connect_type: Local connection type (either UDS or LOCAL_TCP)
+      local_connect_type: Local connection type (either
+        grpc.LocalConnectionType.UDS or grpc.LocalConnectionType.LOCAL_TCP)
 
     Returns:
       A ServerCredentials for use with a local Server

src/python/grpcio/grpc/_cython/_cygrpc/credentials.pyx.pxi

@@ -329,7 +329,7 @@ cdef grpc_ssl_certificate_config_reload_status _server_cert_config_fetcher_wrapp
   return GRPC_SSL_CERTIFICATE_CONFIG_RELOAD_NEW
 
 
-class LocalConnectType:
+class LocalConnectionType:
   uds = UDS
   local_tcp = LOCAL_TCP
 

src/python/grpcio_tests/tests/unit/_local_credentials_test.py

@@ -33,18 +33,20 @@ class LocalCredentialsTest(unittest.TestCase):
         return server
 
     def test_local_tcp(self):
-        server_addr = '[::1]:{}'
+        server_addr = 'localhost:{}'
         channel_creds = grpc.local_channel_credentials(
             grpc.LocalConnectionType.LOCAL_TCP)
         server_creds = grpc.local_server_credentials(
             grpc.LocalConnectionType.LOCAL_TCP)
+
         server = self._create_server()
         port = server.add_secure_port(server_addr.format(0), server_creds)
         server.start()
-        channel = grpc.secure_channel(server_addr.format(port), channel_creds)
-        self.assertEqual(b'abc',
-                         channel.unary_unary('/test/method')(
-                             b'abc', wait_for_ready=True))
+        with grpc.secure_channel(server_addr.format(port),
+                                 channel_creds) as channel:
+            self.assertEqual(b'abc',
+                             channel.unary_unary('/test/method')(
+                                 b'abc', wait_for_ready=True))
         server.stop(None)
 
     def test_uds(self):
@@ -53,13 +55,14 @@ class LocalCredentialsTest(unittest.TestCase):
             grpc.LocalConnectionType.UDS)
         server_creds = grpc.local_server_credentials(
             grpc.LocalConnectionType.UDS)
+
         server = self._create_server()
         server.add_secure_port(server_addr, server_creds)
         server.start()
-        channel = grpc.secure_channel(server_addr, channel_creds)
-        self.assertEqual(b'abc',
-                         channel.unary_unary('/test/method')(
-                             b'abc', wait_for_ready=True))
+        with grpc.secure_channel(server_addr, channel_creds) as channel:
+            self.assertEqual(b'abc',
+                             channel.unary_unary('/test/method')(
+                                 b'abc', wait_for_ready=True))
         server.stop(None)