move OpenTextMode and friends to _typeshed (#4213)

stdlib/2and3/_typeshed/__init__.pyi

@@ -14,6 +14,7 @@
 
 import sys
 from typing import Text, Union
+from typing_extensions import Literal
 
 # StrPath and AnyPath can be used in places where a
 # path can be used instead of a string, starting with Python 3.6.
@@ -26,3 +27,27 @@ else:
     StrPath = Text
     BytesPath = bytes
     AnyPath = Union[Text, bytes]
+
+OpenTextMode = Literal[
+    'r', 'r+', '+r', 'rt', 'tr', 'rt+', 'r+t', '+rt', 'tr+', 't+r', '+tr',
+    'w', 'w+', '+w', 'wt', 'tw', 'wt+', 'w+t', '+wt', 'tw+', 't+w', '+tw',
+    'a', 'a+', '+a', 'at', 'ta', 'at+', 'a+t', '+at', 'ta+', 't+a', '+ta',
+    'x', 'x+', '+x', 'xt', 'tx', 'xt+', 'x+t', '+xt', 'tx+', 't+x', '+tx',
+    'U', 'rU', 'Ur', 'rtU', 'rUt', 'Urt', 'trU', 'tUr', 'Utr',
+]
+OpenBinaryModeUpdating = Literal[
+    'rb+', 'r+b', '+rb', 'br+', 'b+r', '+br',
+    'wb+', 'w+b', '+wb', 'bw+', 'b+w', '+bw',
+    'ab+', 'a+b', '+ab', 'ba+', 'b+a', '+ba',
+    'xb+', 'x+b', '+xb', 'bx+', 'b+x', '+bx',
+]
+OpenBinaryModeWriting = Literal[
+    'wb', 'bw',
+    'ab', 'ba',
+    'xb', 'bx',
+]
+OpenBinaryModeReading = Literal[
+    'rb', 'br',
+    'rbU', 'rUb', 'Urb', 'brU', 'bUr', 'Ubr',
+]
+OpenBinaryMode = Union[OpenBinaryModeUpdating, OpenBinaryModeReading, OpenBinaryModeWriting]

stdlib/2and3/builtins.pyi

@@ -12,20 +12,16 @@ from typing import (
 from abc import ABCMeta
 from ast import mod, AST
 from io import (
-    _OpenBinaryMode, _OpenTextMode, _OpenBinaryModeUpdating, _OpenBinaryModeWriting, _OpenBinaryModeReading,
     TextIOWrapper, FileIO, BufferedRandom, BufferedReader, BufferedWriter
 )
 from types import TracebackType, CodeType
+from _typeshed import AnyPath, OpenBinaryMode, OpenTextMode, OpenBinaryModeUpdating, OpenBinaryModeWriting, OpenBinaryModeReading
+from typing_extensions import Literal
 import sys
 
 if sys.version_info >= (3,):
     from typing import SupportsBytes, SupportsRound
 
-if sys.version_info >= (3, 8):
-    from typing import Literal
-else:
-    from typing_extensions import Literal
-
 if sys.version_info >= (3, 9):
     from types import GenericAlias
 
@@ -1384,18 +1380,14 @@ def next(__i: Iterator[_T], default: _VT) -> Union[_T, _VT]: ...
 def oct(__number: Union[int, _SupportsIndex]) -> str: ...
 
 if sys.version_info >= (3,):
-    if sys.version_info >= (3, 6):
-        # Changed in version 3.6: Support added to accept objects implementing os.PathLike.
-        _OpenFile = Union[str, bytes, int, _PathLike[Any]]
-    else:
-        _OpenFile = Union[str, bytes, int]
+    _OpenFile = Union[AnyPath, int]
     _Opener = Callable[[str, int], int]
 
     # Text mode: always returns a TextIOWrapper
     @overload
     def open(
         file: _OpenFile,
-        mode: _OpenTextMode = ...,
+        mode: OpenTextMode = ...,
         buffering: int = ...,
         encoding: Optional[str] = ...,
         errors: Optional[str] = ...,
@@ -1408,7 +1400,7 @@ if sys.version_info >= (3,):
     @overload
     def open(
         file: _OpenFile,
-        mode: _OpenBinaryMode,
+        mode: OpenBinaryMode,
         buffering: Literal[0],
         encoding: None = ...,
         errors: None = ...,
@@ -1421,7 +1413,7 @@ if sys.version_info >= (3,):
     @overload
     def open(
         file: _OpenFile,
-        mode: _OpenBinaryModeUpdating,
+        mode: OpenBinaryModeUpdating,
         buffering: Literal[-1, 1] = ...,
         encoding: None = ...,
         errors: None = ...,
@@ -1432,7 +1424,7 @@ if sys.version_info >= (3,):
     @overload
     def open(
         file: _OpenFile,
-        mode: _OpenBinaryModeWriting,
+        mode: OpenBinaryModeWriting,
         buffering: Literal[-1, 1] = ...,
         encoding: None = ...,
         errors: None = ...,
@@ -1443,7 +1435,7 @@ if sys.version_info >= (3,):
     @overload
     def open(
         file: _OpenFile,
-        mode: _OpenBinaryModeReading,
+        mode: OpenBinaryModeReading,
         buffering: Literal[-1, 1] = ...,
         encoding: None = ...,
         errors: None = ...,
@@ -1456,7 +1448,7 @@ if sys.version_info >= (3,):
     @overload
     def open(
         file: _OpenFile,
-        mode: _OpenBinaryMode,
+        mode: OpenBinaryMode,
         buffering: int,
         encoding: None = ...,
         errors: None = ...,