Add asyncio.taskgroups and new Task methods (#7240)

Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>

stdlib/asyncio/__init__.pyi

@@ -107,6 +107,9 @@ if sys.version_info >= (3, 7):
         current_task as current_task,
     )
 
+if sys.version_info >= (3, 11):
+    from .taskgroups import TaskGroup as TaskGroup
+
 DefaultEventLoopPolicy: type[AbstractEventLoopPolicy]
 
 if sys.platform == "win32":

stdlib/asyncio/taskgroups.pyi

@@ -0,0 +1,16 @@
+# This only exists in 3.11+. See VERSIONS.
+
+from _typeshed import Self
+from types import TracebackType
+from typing import Any, Coroutine, Generator, TypeVar
+
+from .tasks import Task
+
+_T = TypeVar("_T")
+
+class TaskGroup:
+    def __init__(self, *, name: str | None = ...) -> None: ...
+    def get_name(self) -> str: ...
+    async def __aenter__(self: Self) -> Self: ...
+    async def __aexit__(self, et: type[BaseException] | None, exc: BaseException | None, tb: TracebackType | None) -> None: ...
+    def create_task(self, coro: Generator[Any, None, _T] | Coroutine[Any, Any, _T]) -> Task[_T]: ...

stdlib/asyncio/tasks.pyi

@@ -276,6 +276,9 @@ class Task(Future[_T], Generic[_T]):
         def cancel(self, msg: Any | None = ...) -> bool: ...
     else:
         def cancel(self) -> bool: ...
+    if sys.version_info >= (3, 11):
+        def cancelling(self) -> bool: ...
+        def uncancel(self) -> bool: ...
     if sys.version_info < (3, 9):
         @classmethod
         def current_task(cls, loop: AbstractEventLoop | None = ...) -> Task[Any] | None: ...