Added __class_getitem__ (#4695)

Resolves #4682

Co-authored-by: hauntsaninja <>

stdlib/2and3/_weakref.pyi

@@ -1,6 +1,9 @@
 import sys
 from typing import Any, Callable, Generic, Optional, TypeVar, overload
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _C = TypeVar("_C", bound=Callable[..., Any])
 _T = TypeVar("_T")
 
@@ -16,6 +19,8 @@ class ReferenceType(Generic[_T]):
     def __init__(self, o: _T, callback: Optional[Callable[[ReferenceType[_T]], Any]] = ...) -> None: ...
     def __call__(self) -> Optional[_T]: ...
     def __hash__(self) -> int: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 ref = ReferenceType
 

stdlib/2and3/_weakrefset.pyi

@@ -1,5 +1,9 @@
+import sys
 from typing import Any, Generic, Iterable, Iterator, MutableSet, Optional, TypeVar, Union
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _S = TypeVar("_S")
 _T = TypeVar("_T")
 _SelfT = TypeVar("_SelfT", bound=WeakSet[Any])
@@ -39,3 +43,5 @@ class WeakSet(MutableSet[_T], Generic[_T]):
     def union(self, other: Iterable[_S]) -> WeakSet[Union[_S, _T]]: ...
     def __or__(self, other: Iterable[_S]) -> WeakSet[Union[_S, _T]]: ...
     def isdisjoint(self, other: Iterable[_T]) -> bool: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...

stdlib/2and3/ctypes/__init__.pyi

@@ -21,6 +21,9 @@ from typing import (
     overload,
 )
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _T = TypeVar("_T")
 _DLLT = TypeVar("_DLLT", bound=CDLL)
 _CT = TypeVar("_CT", bound=_CData)
@@ -58,6 +61,8 @@ class LibraryLoader(Generic[_DLLT]):
     def __getattr__(self, name: str) -> _DLLT: ...
     def __getitem__(self, name: str) -> _DLLT: ...
     def LoadLibrary(self, name: str) -> _DLLT: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 cdll: LibraryLoader[CDLL] = ...
 if sys.platform == "win32":
@@ -302,3 +307,5 @@ class Array(Generic[_CT], _CData):
     # Can't inherit from Sized because the metaclass conflict between
     # Sized and _CData prevents using _CDataMeta.
     def __len__(self) -> int: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...

stdlib/2and3/difflib.pyi

@@ -19,6 +19,9 @@ from typing import (
     overload,
 )
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _T = TypeVar("_T")
 
 if sys.version_info >= (3,):
@@ -53,6 +56,8 @@ class SequenceMatcher(Generic[_T]):
     def ratio(self) -> float: ...
     def quick_ratio(self) -> float: ...
     def real_quick_ratio(self) -> float: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 # mypy thinks the signatures of the overloads overlap, but the types still work fine
 @overload

stdlib/2and3/filecmp.pyi

@@ -1,10 +1,13 @@
 # Stubs for filecmp (Python 2/3)
 import sys
-from typing import AnyStr, Callable, Dict, Generic, Iterable, List, Optional, Sequence, Text, Tuple, Union
+from typing import Any, AnyStr, Callable, Dict, Generic, Iterable, List, Optional, Sequence, Text, Tuple, Union
 
 if sys.version_info >= (3, 6):
     from os import PathLike
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 DEFAULT_IGNORES: List[str]
 
 if sys.version_info >= (3, 6):
@@ -41,7 +44,6 @@ class dircmp(Generic[AnyStr]):
     right: AnyStr
     hide: Sequence[AnyStr]
     ignore: Sequence[AnyStr]
-
     # These properties are created at runtime by __getattr__
     subdirs: Dict[AnyStr, dircmp[AnyStr]]
     same_files: List[AnyStr]
@@ -65,6 +67,8 @@ class dircmp(Generic[AnyStr]):
     def phase3(self) -> None: ...
     def phase4(self) -> None: ...
     def phase4_closure(self) -> None: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 if sys.version_info >= (3,):
     def clear_cache() -> None: ...

stdlib/2and3/mailbox.pyi

@@ -1,4 +1,5 @@
 import email.message
+import sys
 from _typeshed import AnyPath
 from types import TracebackType
 from typing import (
@@ -24,6 +25,9 @@ from typing import (
 )
 from typing_extensions import Literal
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _T = TypeVar("_T")
 _MessageType = TypeVar("_MessageType", bound=Message)
 _MessageData = Union[email.message.Message, bytes, str, IO[str], IO[bytes]]
@@ -76,6 +80,8 @@ class Mailbox(Generic[_MessageType]):
     def lock(self) -> None: ...
     def unlock(self) -> None: ...
     def close(self) -> None: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 class Maildir(Mailbox[MaildirMessage]):
 
@@ -188,6 +194,8 @@ class _ProxyFile(Generic[AnyStr]):
     def flush(self) -> None: ...
     @property
     def closed(self) -> bool: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 class _PartialFile(_ProxyFile[AnyStr]):
     def __init__(self, f: IO[AnyStr], start: Optional[int] = ..., stop: Optional[int] = ...) -> None: ...

stdlib/3.7/contextvars.pyi

@@ -1,5 +1,9 @@
+import sys
 from typing import Any, Callable, ClassVar, Generic, Iterator, Mapping, TypeVar
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _T = TypeVar("_T")
 
 class ContextVar(Generic[_T]):
@@ -9,6 +13,8 @@ class ContextVar(Generic[_T]):
     def get(self, default: _T = ...) -> _T: ...
     def set(self, value: _T) -> Token[_T]: ...
     def reset(self, token: Token[_T]) -> None: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 class Token(Generic[_T]):
     @property
@@ -16,6 +22,8 @@ class Token(Generic[_T]):
     @property
     def old_value(self) -> Any: ...  # returns either _T or MISSING, but that's hard to express
     MISSING: ClassVar[object]
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 def copy_context() -> Context: ...
 

stdlib/3.7/dataclasses.pyi

@@ -1,5 +1,9 @@
+import sys
 from typing import Any, Callable, Dict, Generic, Iterable, List, Mapping, Optional, Tuple, Type, TypeVar, Union, overload
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _T = TypeVar("_T")
 
 class _MISSING_TYPE: ...
@@ -32,6 +36,8 @@ class Field(Generic[_T]):
     init: bool
     compare: bool
     metadata: Mapping[str, Any]
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 # NOTE: Actual return type is 'Field[_T]', but we want to help type checkers
 # to understand the magic that happens at runtime.
@@ -68,7 +74,10 @@ def fields(class_or_instance: Any) -> Tuple[Field[Any], ...]: ...
 def is_dataclass(obj: Any) -> bool: ...
 
 class FrozenInstanceError(AttributeError): ...
-class InitVar(Generic[_T]): ...
+
+class InitVar(Generic[_T]):
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, type: Any) -> GenericAlias: ...
 
 def make_dataclass(
     cls_name: str,

stdlib/3/asyncio/futures.pyi

@@ -11,6 +11,9 @@ if sys.version_info < (3, 8):
 if sys.version_info >= (3, 7):
     from contextvars import Context
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _T = TypeVar("_T")
 _S = TypeVar("_S")
 
@@ -58,5 +61,7 @@ class Future(Awaitable[_T], Iterable[_T]):
     def __await__(self) -> Generator[Any, None, _T]: ...
     @property
     def _loop(self) -> AbstractEventLoop: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 def wrap_future(future: Union[_ConcurrentFuture[_T], Future[_T]], *, loop: Optional[AbstractEventLoop] = ...) -> Future[_T]: ...

stdlib/3/asyncio/queues.pyi

@@ -1,5 +1,9 @@
+import sys
 from asyncio.events import AbstractEventLoop
-from typing import Generic, Optional, TypeVar
+from typing import Any, Generic, Optional, TypeVar
+
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
 
 class QueueEmpty(Exception): ...
 class QueueFull(Exception): ...
@@ -25,6 +29,8 @@ class Queue(Generic[_T]):
     def get_nowait(self) -> _T: ...
     async def join(self) -> bool: ...
     def task_done(self) -> None: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, type: Any) -> GenericAlias: ...
 
 class PriorityQueue(Queue[_T]): ...
 class LifoQueue(Queue[_T]): ...

stdlib/3/asyncio/tasks.pyi

@@ -22,6 +22,9 @@ from typing_extensions import Literal
 from .events import AbstractEventLoop
 from .futures import Future
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _T = TypeVar("_T")
 _T1 = TypeVar("_T1")
 _T2 = TypeVar("_T2")
@@ -189,6 +192,8 @@ class Task(Future[_T], Generic[_T]):
         def all_tasks(cls, loop: Optional[AbstractEventLoop] = ...) -> Set[Task[Any]]: ...
     if sys.version_info < (3, 7):
         def _wakeup(self, fut: Future[Any]) -> None: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 if sys.version_info >= (3, 7):
     def all_tasks(loop: Optional[AbstractEventLoop] = ...) -> Set[Task[Any]]: ...

stdlib/3/builtins.pyi

@@ -858,6 +858,8 @@ class enumerate(Iterator[Tuple[int, _T]], Generic[_T]):
     def __init__(self, iterable: Iterable[_T], start: int = ...) -> None: ...
     def __iter__(self) -> Iterator[Tuple[int, _T]]: ...
     def __next__(self) -> Tuple[int, _T]: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 class range(Sequence[int]):
     start: int

stdlib/3/concurrent/futures/_base.pyi

@@ -5,6 +5,9 @@ from logging import Logger
 from types import TracebackType
 from typing import Any, Callable, Container, Generic, Iterable, Iterator, List, Optional, Protocol, Set, Tuple, TypeVar
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 FIRST_COMPLETED: str
 FIRST_EXCEPTION: str
 ALL_COMPLETED: str
@@ -54,6 +57,8 @@ class Future(Generic[_T]):
         def exception_info(self, timeout: Optional[float] = ...) -> Tuple[Any, Optional[TracebackType]]: ...
         def set_exception(self, exception: Any) -> None: ...
         def set_exception_info(self, exception: Any, traceback: Optional[TracebackType]) -> None: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 class Executor:
     if sys.version_info >= (3, 9):

stdlib/3/concurrent/futures/thread.pyi

@@ -7,6 +7,9 @@ if sys.version_info >= (3, 7):
     from ._base import BrokenExecutor
     class BrokenThreadPool(BrokenExecutor): ...
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _S = TypeVar("_S")
 
 class ThreadPoolExecutor(Executor):
@@ -30,3 +33,5 @@ class _WorkItem(Generic[_S]):
     kwargs: Mapping[str, Any]
     def __init__(self, future: Future[_S], fn: Callable[..., _S], args: Iterable[Any], kwargs: Mapping[str, Any]) -> None: ...
     def run(self) -> None: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...

stdlib/3/functools.pyi

@@ -18,6 +18,9 @@ from typing import (
     overload,
 )
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _AnyCallable = Callable[..., Any]
 
 _T = TypeVar("_T")
@@ -68,6 +71,8 @@ class partial(Generic[_T]):
     keywords: Dict[str, Any]
     def __init__(self, func: Callable[..., _T], *args: Any, **kwargs: Any) -> None: ...
     def __call__(self, *args: Any, **kwargs: Any) -> _T: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 # With protocols, this could change into a generic protocol that defines __get__ and returns _T
 _Descriptor = Any
@@ -83,6 +88,8 @@ class partialmethod(Generic[_T]):
     def __get__(self, obj: Any, cls: Type[Any]) -> Callable[..., _T]: ...
     @property
     def __isabstractmethod__(self) -> bool: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 class _SingleDispatchCallable(Generic[_T]):
     registry: Mapping[Any, Callable[..., _T]]
@@ -115,6 +122,8 @@ if sys.version_info >= (3, 8):
         @overload
         def __get__(self, instance: _S, owner: Optional[Type[Any]] = ...) -> _T: ...
         def __set_name__(self, owner: Type[Any], name: str) -> None: ...
+        if sys.version_info >= (3, 9):
+            def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 if sys.version_info >= (3, 9):
     def cache(__user_function: Callable[..., _T]) -> _lru_cache_wrapper[_T]: ...

stdlib/3/multiprocessing/managers.pyi

@@ -30,6 +30,9 @@ if sys.version_info >= (3, 8):
     _SharedMemory = SharedMemory
     _ShareableList = ShareableList
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _T = TypeVar("_T")
 _KT = TypeVar("_KT")
 _VT = TypeVar("_VT")
@@ -89,6 +92,8 @@ class ValueProxy(BaseProxy, Generic[_T]):
     def get(self) -> _T: ...
     def set(self, value: _T) -> None: ...
     value: _T
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 # Returned by BaseManager.get_server()
 class Server:

stdlib/3/multiprocessing/pool.pyi

@@ -1,5 +1,9 @@
+import sys
 from typing import Any, Callable, ContextManager, Generic, Iterable, Iterator, List, Mapping, Optional, TypeVar
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _PT = TypeVar("_PT", bound=Pool)
 _S = TypeVar("_S")
 _T = TypeVar("_T")
@@ -9,6 +13,8 @@ class ApplyResult(Generic[_T]):
     def wait(self, timeout: Optional[float] = ...) -> None: ...
     def ready(self) -> bool: ...
     def successful(self) -> bool: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 # alias created during issue #17805
 AsyncResult = ApplyResult

stdlib/3/multiprocessing/queues.pyi

@@ -1,6 +1,10 @@
 import queue
+import sys
 from typing import Any, Generic, Optional, TypeVar
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _T = TypeVar("_T")
 
 class Queue(queue.Queue[_T]):
@@ -27,3 +31,5 @@ class SimpleQueue(Generic[_T]):
     def empty(self) -> bool: ...
     def get(self) -> _T: ...
     def put(self, item: _T) -> None: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...

stdlib/3/multiprocessing/shared_memory.pyi

@@ -1,5 +1,8 @@
 import sys
-from typing import Generic, Iterable, Optional, Tuple, TypeVar
+from typing import Any, Generic, Iterable, Optional, Tuple, TypeVar
+
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
 
 _S = TypeVar("_S")
 _SLT = TypeVar("_SLT", int, float, bool, str, bytes, None)
@@ -26,3 +29,5 @@ if sys.version_info >= (3, 8):
         def format(self) -> str: ...
         def count(self, value: _SLT) -> int: ...
         def index(self, value: _SLT) -> int: ...
+        if sys.version_info >= (3, 9):
+            def __class_getitem__(cls, item: Any) -> GenericAlias: ...

stdlib/3/os/__init__.pyi

@@ -38,6 +38,9 @@ from typing_extensions import Literal
 
 from . import path as path
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 # We need to use something from path, or flake8 and pytype get unhappy
 _supports_unicode_filenames = path.supports_unicode_filenames
 
@@ -288,6 +291,8 @@ if sys.version_info >= (3, 6):
         def is_symlink(self) -> bool: ...
         def stat(self, *, follow_symlinks: bool = ...) -> stat_result: ...
         def __fspath__(self) -> AnyStr: ...
+        if sys.version_info >= (3, 9):
+            def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 else:
     class DirEntry(Generic[AnyStr]):

stdlib/3/pathlib.pyi

@@ -6,6 +6,9 @@ from types import TracebackType
 from typing import IO, Any, BinaryIO, Generator, List, Optional, Sequence, Text, TextIO, Tuple, Type, TypeVar, Union, overload
 from typing_extensions import Literal
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _P = TypeVar("_P", bound=PurePath)
 
 if sys.version_info >= (3, 6):
@@ -52,6 +55,8 @@ class PurePath(_PurePathBase):
     def parents(self: _P) -> Sequence[_P]: ...
     @property
     def parent(self: _P) -> _P: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, type: Any) -> GenericAlias: ...
 
 class PurePosixPath(PurePath): ...
 class PureWindowsPath(PurePath): ...

stdlib/3/queue.pyi

@@ -6,6 +6,9 @@ import sys
 from threading import Condition, Lock
 from typing import Any, Generic, Optional, TypeVar
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _T = TypeVar("_T")
 
 class Empty(Exception): ...
@@ -34,6 +37,8 @@ class Queue(Generic[_T]):
     def qsize(self) -> int: ...
     def _qsize(self) -> int: ...
     def task_done(self) -> None: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 class PriorityQueue(Queue[_T]): ...
 class LifoQueue(Queue[_T]): ...
@@ -47,3 +52,5 @@ if sys.version_info >= (3, 7):
         def put(self, item: _T, block: bool = ..., timeout: Optional[float] = ...) -> None: ...
         def put_nowait(self, item: _T) -> None: ...
         def qsize(self) -> int: ...
+        if sys.version_info >= (3, 9):
+            def __class_getitem__(cls, item: Any) -> GenericAlias: ...

stdlib/3/subprocess.pyi

@@ -4,6 +4,9 @@ from types import TracebackType
 from typing import IO, Any, AnyStr, Callable, Generic, Mapping, Optional, Sequence, Tuple, Type, TypeVar, Union, overload
 from typing_extensions import Literal
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 # We prefer to annotate inputs to methods (eg subprocess.check_call) with these
 # union types.
 # For outputs we use laborious literal based overloads to try to determine
@@ -38,6 +41,8 @@ class CompletedProcess(Generic[_T]):
     stderr: _T
     def __init__(self, args: _CMD, returncode: int, stdout: Optional[_T] = ..., stderr: Optional[_T] = ...) -> None: ...
     def check_returncode(self) -> None: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 if sys.version_info >= (3, 7):
     # Nearly the same args as for 3.6, except for capture_output and text
@@ -1211,6 +1216,8 @@ class Popen(Generic[AnyStr]):
     def __exit__(
         self, type: Optional[Type[BaseException]], value: Optional[BaseException], traceback: Optional[TracebackType]
     ) -> None: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 # The result really is always a str.
 def getstatusoutput(cmd: _TXT) -> Tuple[int, str]: ...

stdlib/3/tempfile.pyi

@@ -4,6 +4,9 @@ from types import TracebackType
 from typing import IO, Any, AnyStr, Generic, Iterable, Iterator, List, Optional, Tuple, Type, TypeVar, Union, overload
 from typing_extensions import Literal
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 # global variables
 TMP_MAX: int
 tempdir: Optional[str]
@@ -287,6 +290,8 @@ class TemporaryDirectory(Generic[AnyStr]):
     def __exit__(
         self, exc_type: Optional[Type[BaseException]], exc_val: Optional[BaseException], exc_tb: Optional[TracebackType]
     ) -> None: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 def mkstemp(
     suffix: Optional[AnyStr] = ..., prefix: Optional[AnyStr] = ..., dir: Optional[_DirT[AnyStr]] = ..., text: bool = ...

stdlib/3/typing.pyi

@@ -3,6 +3,9 @@ import sys
 from abc import ABCMeta, abstractmethod
 from types import CodeType, FrameType, TracebackType
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 # Definitions of special type checking related constructs.  Their definitions
 # are not used, so their value does not matter.
 
@@ -167,6 +170,8 @@ class Hashable(Protocol, metaclass=ABCMeta):
 class Iterable(Protocol[_T_co]):
     @abstractmethod
     def __iter__(self) -> Iterator[_T_co]: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 @runtime_checkable
 class Iterator(Iterable[_T_co], Protocol[_T_co]):
@@ -201,6 +206,8 @@ class Generator(Iterator[_T_co], Generic[_T_co, _T_contra, _V_co]):
 class Awaitable(Protocol[_T_co]):
     @abstractmethod
     def __await__(self) -> Generator[Any, None, _T_co]: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 class Coroutine(Awaitable[_V_co], Generic[_T_co, _T_contra, _V_co]):
     __name__: str
@@ -236,6 +243,8 @@ class AwaitableGenerator(
 class AsyncIterable(Protocol[_T_co]):
     @abstractmethod
     def __aiter__(self) -> AsyncIterator[_T_co]: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 @runtime_checkable
 class AsyncIterator(AsyncIterable[_T_co], Protocol[_T_co]):
@@ -274,6 +283,8 @@ if sys.version_info >= (3, 6):
 class Container(Protocol[_T_co]):
     @abstractmethod
     def __contains__(self, __x: object) -> bool: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 if sys.version_info >= (3, 6):
     @runtime_checkable
@@ -364,6 +375,8 @@ class MutableSet(AbstractSet[_T], Generic[_T]):
 class MappingView(Sized):
     def __init__(self, mapping: Mapping[_KT_co, _VT_co]) -> None: ...  # undocumented
     def __len__(self) -> int: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 class ItemsView(MappingView, AbstractSet[Tuple[_KT_co, _VT_co]], Generic[_KT_co, _VT_co]):
     def __init__(self, mapping: Mapping[_KT_co, _VT_co]) -> None: ...  # undocumented
@@ -568,6 +581,8 @@ class Match(Generic[AnyStr]):
     def regs(self) -> Tuple[Tuple[int, int], ...]: ...  # undocumented
     if sys.version_info >= (3, 6):
         def __getitem__(self, g: Union[int, str]) -> AnyStr: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 class Pattern(Generic[AnyStr]):
     flags: int
@@ -589,6 +604,8 @@ class Pattern(Generic[AnyStr]):
     def subn(self, repl: AnyStr, string: AnyStr, count: int = ...) -> Tuple[AnyStr, int]: ...
     @overload
     def subn(self, repl: Callable[[Match[AnyStr]], AnyStr], string: AnyStr, count: int = ...) -> Tuple[AnyStr, int]: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 # Functions
 

stdlib/3/unittest/case.pyi

@@ -28,6 +28,9 @@ from typing import (
 )
 from warnings import WarningMessage
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _E = TypeVar("_E", bound=BaseException)
 _FT = TypeVar("_FT", bound=Callable[..., Any])
 
@@ -258,6 +261,8 @@ class _AssertRaisesContext(Generic[_E]):
     def __exit__(
         self, exc_type: Optional[Type[BaseException]], exc_val: Optional[BaseException], exc_tb: Optional[TracebackType]
     ) -> bool: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 class _AssertWarnsContext:
     warning: WarningMessage

stdlib/3/urllib/parse.pyi

@@ -2,6 +2,9 @@
 import sys
 from typing import Any, AnyStr, Callable, Dict, Generic, List, Mapping, NamedTuple, Optional, Sequence, Tuple, Union, overload
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _Str = Union[bytes, str]
 
 uses_relative: List[str]
@@ -27,6 +30,8 @@ class _NetlocResultMixinBase(Generic[AnyStr]):
     password: Optional[AnyStr]
     hostname: Optional[AnyStr]
     port: Optional[int]
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 class _NetlocResultMixinStr(_NetlocResultMixinBase[str], _ResultMixinStr): ...
 class _NetlocResultMixinBytes(_NetlocResultMixinBase[bytes], _ResultMixinBytes): ...

third_party/2/concurrent/futures/_base.pyi

@@ -5,6 +5,9 @@ from logging import Logger
 from types import TracebackType
 from typing import Any, Callable, Container, Generic, Iterable, Iterator, List, Optional, Protocol, Set, Tuple, TypeVar
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 FIRST_COMPLETED: str
 FIRST_EXCEPTION: str
 ALL_COMPLETED: str
@@ -54,6 +57,8 @@ class Future(Generic[_T]):
         def exception_info(self, timeout: Optional[float] = ...) -> Tuple[Any, Optional[TracebackType]]: ...
         def set_exception(self, exception: Any) -> None: ...
         def set_exception_info(self, exception: Any, traceback: Optional[TracebackType]) -> None: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 class Executor:
     if sys.version_info >= (3, 9):

third_party/2/concurrent/futures/thread.pyi

@@ -7,6 +7,9 @@ if sys.version_info >= (3, 7):
     from ._base import BrokenExecutor
     class BrokenThreadPool(BrokenExecutor): ...
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _S = TypeVar("_S")
 
 class ThreadPoolExecutor(Executor):
@@ -30,3 +33,5 @@ class _WorkItem(Generic[_S]):
     kwargs: Mapping[str, Any]
     def __init__(self, future: Future[_S], fn: Callable[..., _S], args: Iterable[Any], kwargs: Mapping[str, Any]) -> None: ...
     def run(self) -> None: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...

third_party/2/pathlib2.pyi

@@ -6,6 +6,9 @@ from types import TracebackType
 from typing import IO, Any, BinaryIO, Generator, List, Optional, Sequence, Text, TextIO, Tuple, Type, TypeVar, Union, overload
 from typing_extensions import Literal
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _P = TypeVar("_P", bound=PurePath)
 
 if sys.version_info >= (3, 6):
@@ -52,6 +55,8 @@ class PurePath(_PurePathBase):
     def parents(self: _P) -> Sequence[_P]: ...
     @property
     def parent(self: _P) -> _P: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, type: Any) -> GenericAlias: ...
 
 class PurePosixPath(PurePath): ...
 class PureWindowsPath(PurePath): ...

third_party/3/contextvars.pyi

@@ -1,5 +1,9 @@
+import sys
 from typing import Any, Callable, ClassVar, Generic, Iterator, Mapping, TypeVar
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _T = TypeVar("_T")
 
 class ContextVar(Generic[_T]):
@@ -9,6 +13,8 @@ class ContextVar(Generic[_T]):
     def get(self, default: _T = ...) -> _T: ...
     def set(self, value: _T) -> Token[_T]: ...
     def reset(self, token: Token[_T]) -> None: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 class Token(Generic[_T]):
     @property
@@ -16,6 +22,8 @@ class Token(Generic[_T]):
     @property
     def old_value(self) -> Any: ...  # returns either _T or MISSING, but that's hard to express
     MISSING: ClassVar[object]
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 def copy_context() -> Context: ...
 

third_party/3/dataclasses.pyi

@@ -1,5 +1,9 @@
+import sys
 from typing import Any, Callable, Dict, Generic, Iterable, List, Mapping, Optional, Tuple, Type, TypeVar, Union, overload
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _T = TypeVar("_T")
 
 class _MISSING_TYPE: ...
@@ -32,6 +36,8 @@ class Field(Generic[_T]):
     init: bool
     compare: bool
     metadata: Mapping[str, Any]
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 # NOTE: Actual return type is 'Field[_T]', but we want to help type checkers
 # to understand the magic that happens at runtime.
@@ -68,7 +74,10 @@ def fields(class_or_instance: Any) -> Tuple[Field[Any], ...]: ...
 def is_dataclass(obj: Any) -> bool: ...
 
 class FrozenInstanceError(AttributeError): ...
-class InitVar(Generic[_T]): ...
+
+class InitVar(Generic[_T]):
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, type: Any) -> GenericAlias: ...
 
 def make_dataclass(
     cls_name: str,