mypy m2m iterator fix (#655)

* feat: add type hint for items in iterators for m2m relations

* chore: make flake8 happy
- rename some variables
- reorder some imports

* switch to typing.List

Co-authored-by: Benjamin Mollier <benjamin.mollier@meetap.de>
Co-authored-by: collerek <collerek@gmail.com>

ormar/fields/model_fields.py

@@ -1,7 +1,7 @@
 import datetime
 import decimal
 import uuid
-from enum import EnumMeta, Enum as E
+from enum import Enum as E, EnumMeta
 from typing import Any, Optional, Set, TYPE_CHECKING, Type, TypeVar, Union, overload
 
 import pydantic

ormar/models/mixins/save_mixin.py

@@ -79,9 +79,9 @@ class SavePrepareMixin(RelationMixin, AliasMixin):
 
     @classmethod
     def translate_enum_columns(cls, new_kwargs: dict) -> dict:
-        for k, v in new_kwargs.items():
+        for key, value in new_kwargs.items():
-            if isinstance(v, Enum):
+            if isinstance(value, Enum):
-                new_kwargs[k] = v.name
+                new_kwargs[key] = value.name
         return new_kwargs
 
     @classmethod

ormar/models/newbasemodel.py

@@ -22,8 +22,6 @@ from typing import (
 import databases
 import pydantic
 import sqlalchemy
-
-
 from pydantic import BaseModel
 
 

ormar/relations/relation_proxy.py

@@ -1,4 +1,4 @@
-from typing import Any, Generic, Optional, TYPE_CHECKING, Type, TypeVar
+from typing import Any, Generic, List, Optional, TYPE_CHECKING, Type, TypeVar
 
 import ormar
 from ormar.exceptions import NoMatch, RelationshipInstanceError
@@ -13,7 +13,7 @@ else:
     T = TypeVar("T", bound="Model")
 
 
-class RelationProxy(Generic[T], list):
+class RelationProxy(Generic[T], List[T]):
     """
     Proxy of the Relation that is a list with special methods.
     """

tests/test_types.py

@@ -86,6 +86,7 @@ async def test_types() -> None:
         #     reveal_type(publisher)  # model method
         #     reveal_type(publishers)  # many to many
         #     reveal_type(publishers[0])  # item in m2m list
+        #     reveal_type(next(p for p in publishers))  # item in m2m iterator
         #     # getting relation without __getattribute__
         #     reveal_type(authors)  # reverse many to many  # TODO: wrong
         #     reveal_type(book2)  # queryset get