Literal: always import from typing_extensions for simplicity (#4219)

third_party/2and3/dateutil/easter.pyi

@@ -1,9 +1,5 @@
 from datetime import date
-import sys
-if sys.version_info >= (3, 8):
-    from typing import Literal
-else:
-    from typing_extensions import Literal
+from typing_extensions import Literal
 
 EASTER_JULIAN: Literal[1]
 EASTER_ORTHODOX: Literal[2]

third_party/2and3/jinja2/utils.pyi

@@ -1,5 +1,5 @@
-import sys
 from typing import Any, Callable, IO, Iterable, Optional, Protocol, Text, TypeVar, Union
+from typing_extensions import Literal
 from _typeshed import AnyPath
 
 from markupsafe import Markup as Markup, escape as escape, soft_unicode as soft_unicode
@@ -8,24 +8,18 @@ missing: Any
 internal_code: Any
 concat: Any
 
-if sys.version_info >= (3, 8):
-    from typing import Literal
-    _True = Literal[True]
-else:
-    _True = bool
-
 _CallableT = TypeVar("_CallableT", bound=Callable[..., Any])
 
 class _ContextFunction(Protocol[_CallableT]):
-    contextfunction: _True
+    contextfunction: Literal[True]
     __call__: _CallableT
 
 class _EvalContextFunction(Protocol[_CallableT]):
-    evalcontextfunction: _True
+    evalcontextfunction: Literal[True]
     __call__: _CallableT
 
 class _EnvironmentFunction(Protocol[_CallableT]):
-    environmentfunction: _True
+    environmentfunction: Literal[True]
     __call__: _CallableT
 
 def contextfunction(f: _CallableT) -> _ContextFunction[_CallableT]: ...

third_party/2and3/werkzeug/wrappers.pyi

@@ -3,6 +3,7 @@ from datetime import datetime
 from typing import (
     Any, Callable, Iterable, Iterator, Mapping, MutableMapping, Optional, Sequence, Text, Tuple, Type, TypeVar, Union, overload
 )
+from typing_extensions import Literal
 from _typeshed.wsgi import WSGIEnvironment, InputStream
 
 from .datastructures import (
@@ -12,11 +13,6 @@ from .datastructures import (
 )
 from .useragents import UserAgent
 
-if sys.version_info >= (3, 8):
-    from typing import Literal
-else:
-    from typing_extensions import Literal
-
 class BaseRequest:
     charset: str
     encoding_errors: str