Added __class_getitem__ (#4695)

Resolves #4682

Co-authored-by: hauntsaninja <>

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,