Add a _typeshed.pyi file and a PathLike alias (#4161)

stdlib/2and3/_typeshed/__init__.pyi

@@ -0,0 +1,28 @@
+# Utility types for typeshed
+
+# This module contains various common types to be used by typeshed. The
+# module and its types do not exist at runtime. You can use this module
+# outside of typeshed, but no API stability guarantees are made. To use
+# it in implementation (.py) files, the following construct must be used:
+#
+#     from typing import TYPE_CHECKING
+#     if TYPE_CHECKING:
+#         from _typeshed import ...
+#
+# If on Python versions < 3.10 and "from __future__ import annotations"
+# is not used, types from this module must be quoted.
+
+import sys
+from typing import Text, Union
+
+# StrPath and AnyPath can be used in places where a
+# path can be used instead of a string, starting with Python 3.6.
+if sys.version_info >= (3, 6):
+    from os import PathLike
+    StrPath = Union[str, PathLike[str]]
+    BytesPath = Union[bytes, PathLike[bytes]]
+    AnyPath = Union[str, bytes, PathLike[str], PathLike[bytes]]
+else:
+    StrPath = Text
+    BytesPath = bytes
+    AnyPath = Union[Text, bytes]

tests/stubtest_whitelists/py3_common.txt

@@ -5,6 +5,7 @@ _importlib_modulespec
 _operator.methodcaller
 _threading_local.local.__new__
 _types
+_typeshed
 _weakref.CallableProxyType.__getattr__
 _weakref.ProxyType.__getattr__
 _weakref.ReferenceType.__call__

third_party/2and3/atomicwrites/__init__.pyi

@@ -1,22 +1,17 @@
 import sys
 from typing import Any, AnyStr, Callable, ContextManager, Generic, IO, Optional, Text, Type, Union
-
-if sys.version_info >= (3, 6):
-    from os import PathLike
-    _Path = Union[str, bytes, PathLike[str], PathLike[bytes]]
-else:
-    _Path = Union[Text, bytes]
+from _typeshed import AnyPath
 
 def replace_atomic(src: AnyStr, dst: AnyStr) -> None: ...
 def move_atomic(src: AnyStr, dst: AnyStr) -> None: ...
 class AtomicWriter(object):
-    def __init__(self, path: _Path, mode: Text = ..., overwrite: bool = ...) -> None: ...
+    def __init__(self, path: AnyPath, mode: Text = ..., overwrite: bool = ...) -> None: ...
     def open(self) -> ContextManager[IO[Any]]: ...
     def _open(self, get_fileobject: Callable[..., IO[AnyStr]]) -> ContextManager[IO[AnyStr]]: ...
-    def get_fileobject(self, dir: Optional[_Path] = ..., **kwargs: Any) -> IO[Any]: ...
+    def get_fileobject(self, dir: Optional[AnyPath] = ..., **kwargs: Any) -> IO[Any]: ...
     def sync(self, f: IO[Any]) -> None: ...
     def commit(self, f: IO[Any]) -> None: ...
     def rollback(self, f: IO[Any]) -> None: ...
 def atomic_write(
-    path: _Path, writer_cls: Type[AtomicWriter] = ..., **cls_kwargs: object,
+    path: AnyPath, writer_cls: Type[AtomicWriter] = ..., **cls_kwargs: object,
 ) -> ContextManager[IO[Any]]: ...

third_party/2and3/jinja2/utils.pyi

@@ -1,5 +1,6 @@
 import sys
 from typing import Any, Callable, IO, Iterable, Optional, Protocol, Text, TypeVar, Union
+from _typeshed import AnyPath
 
 from markupsafe import Markup as Markup, escape as escape, soft_unicode as soft_unicode
 
@@ -13,12 +14,6 @@ if sys.version_info >= (3, 8):
 else:
     _True = bool
 
-if sys.version_info >= (3, 6):
-    from builtins import _PathLike
-    _PathType = Union[bytes, Text, _PathLike]
-else:
-    _PathType = Union[bytes, Text]
-
 _CallableT = TypeVar("_CallableT", bound=Callable[..., Any])
 
 class _ContextFunction(Protocol[_CallableT]):
@@ -42,7 +37,7 @@ def select_autoescape(enabled_extensions: Iterable[str] = ..., disabled_extensio
 def consume(iterable: Iterable[object]) -> None: ...
 def clear_caches() -> None: ...
 def import_string(import_name: str, silent: bool = ...) -> Any: ...
-def open_if_exists(filename: _PathType, mode: str = ...) -> Optional[IO[Any]]: ...
+def open_if_exists(filename: AnyPath, mode: str = ...) -> Optional[IO[Any]]: ...
 def object_type_repr(obj: object) -> str: ...
 def pformat(obj: object, verbose: bool = ...) -> str: ...
 def urlize(text: Union[Markup, Text], trim_url_limit: Optional[int] = ..., rel: Optional[Union[Markup, Text]] = ..., target: Optional[Union[Markup, Text]] = ...) -> str: ...

third_party/2and3/toml.pyi

@@ -1,16 +1,15 @@
 from typing import Any, IO, List, Mapping, MutableMapping, Optional, Protocol, Text, Type, Union
+from _typeshed import StrPath
 import datetime
 import sys
 
-if sys.version_info >= (3, 4):
+if sys.version_info >= (3, 6):
+    _PathLike = StrPath
+elif sys.version_info >= (3, 4):
     import pathlib
-    if sys.version_info >= (3, 6):
-        import os
-        _PathLike = Union[Text, pathlib.PurePath, os.PathLike]
-    else:
-        _PathLike = Union[Text, pathlib.PurePath]
+    _PathLike = Union[StrPath, pathlib.PurePath]
 else:
-    _PathLike = Text
+    _PathLike = StrPath
 
 class _Writable(Protocol):
     def write(self, obj: str) -> Any: ...