Fix CI linting issues

- Fix isort import ordering in generated gRPC stub files
- Rename loop variables to avoid shadowing imported 'enum' module
- Remove trailing comma causing useless tuple expression warning
- Add Y026 to flake8 ignore list for generated .pyi files

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: WouldYouKindly

.flake8

@@ -1,8 +1,8 @@
 [flake8]
 per-file-ignores =
   *.py: E203, E301, E302, E305, E501
-  *.pyi: E301, E302, E305, E501, E701, E741, F401, F403, F405, F822, Y037
-  *_pb2.pyi: E301, E302, E305, E501, E701, E741, F401, F403, F405, F822, Y037, Y021, Y053
-  *_pb2_grpc.pyi: E301, E302, E305, E501, E701, E741, F401, F403, F405, F822, Y037, Y021, Y023, Y053
+  *.pyi: E301, E302, E305, E501, E701, E741, F401, F403, F405, F822, Y026, Y037
+  *_pb2.pyi: E301, E302, E305, E501, E701, E741, F401, F403, F405, F822, Y026, Y021, Y037, Y053
+  *_pb2_grpc.pyi: E301, E302, E305, E501, E701, E741, F401, F403, F405, F822, Y026, Y021, Y023, Y037, Y053
 
 extend_exclude = venv*,*_pb2.py,*_pb2_grpc.py,build/

mypy_protobuf/main.py

@@ -120,9 +120,9 @@ def _add_enums(
             prefix: str,
             _fd: d.FileDescriptorProto,
         ) -> None:
-            for enum in enums:
-                self.message_to_fd[prefix + enum.name] = _fd
-                self.message_to_fd[prefix + enum.name + ".ValueType"] = _fd
+            for enum_proto in enums:
+                self.message_to_fd[prefix + enum_proto.name] = _fd
+                self.message_to_fd[prefix + enum_proto.name + ".ValueType"] = _fd
 
         def _add_messages(
             messages: "RepeatedCompositeFieldContainer[d.DescriptorProto]",
@@ -411,12 +411,12 @@ def write_enums(
         scl_prefix: SourceCodeLocation,
     ) -> None:
         wl = self._write_line
-        for i, enum in enumerate(enums):
-            class_name = enum.name if enum.name not in PYTHON_RESERVED else "_r_" + enum.name
+        for i, enum_proto in enumerate(enums):
+            class_name = enum_proto.name if enum_proto.name not in PYTHON_RESERVED else "_r_" + enum_proto.name
             value_type_fq = prefix + class_name + ".ValueType"
-            enum_helper_class = "_" + enum.name
+            enum_helper_class = "_" + enum_proto.name
             value_type_helper_fq = prefix + enum_helper_class + ".ValueType"
-            etw_helper_class = "_" + enum.name + "EnumTypeWrapper"
+            etw_helper_class = "_" + enum_proto.name + "EnumTypeWrapper"
             scl = scl_prefix + [i]
 
             wl(f"class {enum_helper_class}:")
@@ -440,13 +440,13 @@ def write_enums(
                 ed = self._import("google.protobuf.descriptor", "EnumDescriptor")
                 wl(f"DESCRIPTOR: {ed}")
                 self.write_enum_values(
-                    [(i, v) for i, v in enumerate(enum.value) if v.name not in PROTO_ENUM_RESERVED],
+                    [(i, v) for i, v in enumerate(enum_proto.value) if v.name not in PROTO_ENUM_RESERVED],
                     value_type_helper_fq,
                     scl + [d.EnumDescriptorProto.VALUE_FIELD_NUMBER],
                 )
             wl("")
 
-            if enum.options.deprecated:
+            if enum_proto.options.deprecated:
                 self._write_deprecation_warning(
                     scl + [d.EnumDescriptorProto.OPTIONS_FIELD_NUMBER] + [d.EnumOptions.DEPRECATED_FIELD_NUMBER],
                     "This enum has been marked as deprecated using proto enum options.",
@@ -462,7 +462,7 @@ def write_enums(
                     wl("")
 
             self.write_enum_values(
-                enumerate(enum.value),
+                enumerate(enum_proto.value),
                 value_type_fq,
                 scl + [d.EnumDescriptorProto.VALUE_FIELD_NUMBER],
             )
@@ -823,7 +823,7 @@ def write_grpc_iterator_type(self) -> None:
         if self.grpc_type == GRPCType.SYNC:
             self._import("collections.abc", "Iterator")
         elif self.grpc_type == GRPCType.ASYNC:
-            self._import("collections.abc", "AsyncIterator"),
+            self._import("collections.abc", "AsyncIterator")
         else:
             # _MaybeAsyncIterator[Req] is supertyped by Iterator[Req] and AsyncIterator[Req].
             # So both can be used in the contravariant function parameter position.

test/generated-async-only/testproto/grpc/dummy_pb2_grpc.py

@@ -1,8 +1,8 @@
 # Generated by the gRPC Python protocol compiler plugin. DO NOT EDIT!
 """Client and server classes corresponding to protobuf-defined services."""
-import grpc
 import warnings
 
+import grpc
 from testproto.grpc import dummy_pb2 as testproto_dot_grpc_dot_dummy__pb2
 
 GRPC_GENERATED_VERSION = '1.76.0'

test/generated-async-only/testproto/grpc/import_pb2_grpc.py

@@ -1,8 +1,8 @@
 # Generated by the gRPC Python protocol compiler plugin. DO NOT EDIT!
 """Client and server classes corresponding to protobuf-defined services."""
-import grpc
 import warnings
 
+import grpc
 from google.protobuf import empty_pb2 as google_dot_protobuf_dot_empty__pb2
 from testproto import test_pb2 as testproto_dot_test__pb2
 

test/generated-sync-only/testproto/grpc/dummy_pb2_grpc.py

@@ -1,8 +1,8 @@
 # Generated by the gRPC Python protocol compiler plugin. DO NOT EDIT!
 """Client and server classes corresponding to protobuf-defined services."""
-import grpc
 import warnings
 
+import grpc
 from testproto.grpc import dummy_pb2 as testproto_dot_grpc_dot_dummy__pb2
 
 GRPC_GENERATED_VERSION = '1.76.0'

test/generated-sync-only/testproto/grpc/import_pb2_grpc.py

@@ -1,8 +1,8 @@
 # Generated by the gRPC Python protocol compiler plugin. DO NOT EDIT!
 """Client and server classes corresponding to protobuf-defined services."""
-import grpc
 import warnings
 
+import grpc
 from google.protobuf import empty_pb2 as google_dot_protobuf_dot_empty__pb2
 from testproto import test_pb2 as testproto_dot_test__pb2