python · belm0 · Apr 26, 2026 · Apr 27, 2026 · picnixz · Apr 27, 2026
@@ -394,8 +394,8 @@ Example::
 The ``async with`` statement will wait for all tasks in the group to finish.
 While waiting, new tasks may still be added to the group
 (for example, by passing ``tg`` into one of the coroutines
-and calling ``tg.create_task()`` in that coroutine).  There is also opportunity
-to short-circuit the entire task group with ``tg.cancel()``, based on some condition.
+and calling ``tg.create_task()`` in that coroutine).  There is also opportunity to
+request termination of the entire task group with ``tg.cancel()``, based on some condition.
 Once the last task has finished and the ``async with`` block is exited,
 no new tasks may be added to the group.
 

@@ -717,6 +717,14 @@ ast
   This can be :ref:`controlled using environment variables <using-on-controlling-color>`.
   (Contributed by Stan Ulbrych in :gh:`148981`.)
 
+asyncio
+-------
+
+* Added :meth:`~asyncio.TaskGroup.cancel` to allow early termination of a task group --
+  e.g. when the goal of the tasks has been achieved or their services no longer needed.
+  Previously this would involve unintuitive boilerplate such as an extra task raising
+  a custom exception which is then suppressed as it exits TaskGroup.
+  (Contributed by John Belmonte in :gh:`127214`.)
 
 base64
-  (Contributed by Stan Ulbrych in :gh:`148981`.)
-
-asyncio
-------
-
-* Added :meth:`~asyncio.TaskGroup.cancel` to allow early termination of a task group --
-  e.g. when the goal of the tasks has been achieved or their services no longer needed.
-  Previously this would involve unintuitive boilerplate such as an extra task raising
-  a custom exception which is then suppressed as it exits TaskGroup.
-  (Contributed by John Belmonte in :gh:`127214`.)
-
-base64
+  (Contributed by Stan Ulbrych in :gh:`148981`.)
+
+
+asyncio
+-------
+
+* Added :meth:`~asyncio.TaskGroup.cancel` to allow early termination of a task group,
+  for instance, when the goal of the tasks has been achieved or their services
+  no longer needed. Previously this would involve unintuitive boilerplate such
+  as an extra task raising a custom exception which is then suppressed as it
+  exits the task group.
+  (Contributed by John Belmonte in :gh:`127214`.)
+
+
+base64
-  (Contributed by Stan Ulbrych in :gh:`148981`.)
-
-asyncio
-------
-
-* Added :meth:`~asyncio.TaskGroup.cancel` to allow early termination of a task group --
-  e.g. when the goal of the tasks has been achieved or their services no longer needed.
-  Previously this would involve unintuitive boilerplate such as an extra task raising
-  a custom exception which is then suppressed as it exits TaskGroup.
-  (Contributed by John Belmonte in :gh:`127214`.)
-
-base64
+  (Contributed by Stan Ulbrych in :gh:`148981`.)
+
+
+asyncio
+-------
+
+* Added :meth:`~asyncio.TaskGroup.cancel` to allow early termination of a task group,
+  for instance, when the goal of the tasks has been achieved or their services
+  no longer needed. Previously this would involve unintuitive boilerplate such
+  as an extra task raising a custom exception which is then suppressed as it
+  exits the task group.
+  (Contributed by John Belmonte in :gh:`127214`.)
+
+
+base64
 ------

diff --git a/Misc/NEWS.d/next/Library/2024-11-24-07-18-40.gh-issue-108951.jyKygP.rst b/Misc/NEWS.d/next/Library/2024-11-24-07-18-40.gh-issue-108951.jyKygP.rst
@@ -1 +1 @@
-Add :meth:`~asyncio.TaskGroup.cancel` which cancels unfinished tasks and exits the group without error.
+Add :meth:`~asyncio.TaskGroup.cancel` which cancels unfinished tasks and exits the group without raising :exc:`asyncio.CancelledError`.
Original file line number	Diff line number	Diff line change
		@@ -1 +1 @@
		Add :meth:`~asyncio.TaskGroup.cancel` which cancels unfinished tasks and exits the group without error.
		Add :meth:`~asyncio.TaskGroup.cancel` which cancels unfinished tasks and exits the group without raising :exc:`asyncio.CancelledError`.
Copy link Copy Markdown Contributor agronholm Apr 26, 2026 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others. Learn more. I'm still not sure if the explicit "and exits the group without raising :exc:`asyncio.CancelledError`" makes sense. All this does is 1) cancel all current tasks in the group and 2) set the task group into aborted mode which causes creation of further tasks to fail. With that in mind, I'm not sure why you chose to explicitly mention exiting the task group. Copy link Copy Markdown Contributor agronholm Apr 26, 2026 • edited Loading Choose a reason for hiding this comment The reason will be displayed to describe this comment to others. Learn more. Further, this still begs to question why you said "without raising :exc:`asyncio.CancelledError`". This implies that otherwise it would raise a `CancelledError`, yes? Copy link Copy Markdown Contributor Author belm0 Apr 27, 2026 • edited Loading Choose a reason for hiding this comment The reason will be displayed to describe this comment to others. Learn more. well, if you check the long discussions in the impl PR, there was quite a bit made about possible confusion from expecting TaskGroup.cancel() to behave like Task.cancel(). So this is being explicit that unlike the latter, TaskGroup.cancel() does not cause anything to raise CancelledError. Copy link Copy Markdown Contributor agronholm Apr 27, 2026 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others. Learn more. I think this could be reworded: Add :meth:`~asyncio.TaskGroup.cancel` which cancels unfinished tasks in the group and prevents new ones from being created. If this requires cancellation of the host task, the task group will swallow the :exc:`asyncio.CancelledError`, unless the task was also cancelled from elsewhere. Thoughts?