introduce direction literal / import consolidation #582

drf_spectacular/drainage.py

@@ -4,6 +4,13 @@
 from collections import defaultdict
 from typing import DefaultDict
 
+if sys.version_info >= (3, 8):
+    from typing import Final, Literal, _TypedDictMeta  # type: ignore[attr-defined] # noqa: F401
+else:
+    from typing_extensions import (  # type: ignore[attr-defined] # noqa: F401
+        Final, Literal, _TypedDictMeta,
+    )
+
 
 class GeneratorStats:
     _warn_cache: DefaultDict[str, int] = defaultdict(int)

drf_spectacular/extensions.py

@@ -2,6 +2,7 @@
 from typing import TYPE_CHECKING, Any, Dict, List, Optional, Type, Union
 
 from drf_spectacular.plumbing import OpenApiGeneratorExtension
+from drf_spectacular.utils import Direction
 
 if TYPE_CHECKING:
     from rest_framework.views import APIView
@@ -58,7 +59,7 @@ def get_name(self) -> Optional[str]:
         """ return str for overriding default name extraction """
         return None
 
-    def map_serializer(self, auto_schema: 'AutoSchema', direction):
+    def map_serializer(self, auto_schema: 'AutoSchema', direction: Direction):
         """ override for customized serializer mapping """
         return auto_schema._map_serializer(self.target_class, direction, bypass_extensions=True)
 
@@ -82,7 +83,7 @@ def get_name(self) -> Optional[str]:
         return None
 
     @abstractmethod
-    def map_serializer_field(self, auto_schema: 'AutoSchema', direction):
+    def map_serializer_field(self, auto_schema: 'AutoSchema', direction: Direction):
         """ override for customized serializer field mapping """
         pass  # pragma: no cover
 

drf_spectacular/plumbing.py

@@ -13,11 +13,6 @@
 from enum import Enum
 from typing import DefaultDict, Generic, List, Optional, Type, TypeVar, Union
 
-if sys.version_info >= (3, 8):
-    from typing import Literal, _TypedDictMeta  # type: ignore[attr-defined]
-else:
-    from typing_extensions import Literal, _TypedDictMeta  # type: ignore[attr-defined]
-
 import inflection
 import uritemplate
 from django.apps import apps
@@ -42,7 +37,7 @@
 from rest_framework.utils.mediatypes import _MediaType
 from uritemplate import URITemplate
 
-from drf_spectacular.drainage import cache, error, warn
+from drf_spectacular.drainage import Literal, _TypedDictMeta, cache, error, warn
 from drf_spectacular.settings import spectacular_settings
 from drf_spectacular.types import (
     DJANGO_PATH_CONVERTER_MAPPING, OPENAPI_TYPE_MAPPING, PYTHON_TYPE_MAPPING, OpenApiTypes,

drf_spectacular/utils.py

@@ -1,26 +1,19 @@
 import inspect
-import sys
 from typing import Any, Callable, Dict, List, Optional, Tuple, Type, TypeVar, Union
 
 from rest_framework.fields import Field, empty
 from rest_framework.serializers import Serializer
 from rest_framework.settings import api_settings
 
 from drf_spectacular.drainage import (
-    error, get_view_method_names, isolate_view_method, set_override, warn,
+    Final, Literal, error, get_view_method_names, isolate_view_method, set_override, warn,
 )
 from drf_spectacular.types import OpenApiTypes, _KnownPythonTypes
 
-if sys.version_info >= (3, 8):
-    from typing import Final, Literal
-else:
-    from typing_extensions import Final, Literal
-
-
 _SerializerType = Union[Serializer, Type[Serializer]]
 _FieldType = Union[Field, Type[Field]]
-
 _ParameterLocationType = Literal['query', 'path', 'header', 'cookie']
+Direction = Literal['request', 'response']
 
 
 class PolymorphicProxySerializer(Serializer):