Refomat with black

aiohttp/client_exceptions.py

@@ -168,8 +168,10 @@ class UnixClientConnectorError(ClientConnectorError):
     Raised in :py:class:`aiohttp.connector.UnixConnector`
     if connection to unix socket can not be established.
     """
-    def __init__(self, path: str, connection_key: ConnectionKey,
-                 os_error: OSError) -> None:
+
+    def __init__(
+        self, path: str, connection_key: ConnectionKey, os_error: OSError
+    ) -> None:
         self._path = path
         super().__init__(connection_key, os_error)
 
@@ -178,9 +180,9 @@ def path(self) -> str:
         return self._path
 
     def __str__(self) -> str:
-        return ('Cannot connect to unix socket {0.path} ssl:{1} [{2}]'
-                .format(self, self.ssl if self.ssl is not None else 'default',
-                        self.strerror))
+        return "Cannot connect to unix socket {0.path} ssl:{1} [{2}]".format(
+            self, self.ssl if self.ssl is not None else "default", self.strerror
+        )
 
 
 class ServerConnectionError(ClientConnectionError):

aiohttp/connector.py

@@ -1163,9 +1163,7 @@ async def _create_connection(
                     self._factory, self._path
                 )
         except OSError as exc:
-            raise UnixClientConnectorError(
-                self.path, req.connection_key, exc
-            ) from exc
+            raise UnixClientConnectorError(self.path, req.connection_key, exc) from exc
 
         return cast(ResponseHandler, proto)