handle BaseExceptionGroup in contextlib.suppress()

Author: Zac-HD

Doc/library/contextlib.rst

@@ -304,8 +304,8 @@ Functions and classes provided:
 
    This context manager is :ref:`reentrant <reentrant-cms>`.
 
-   If the code within the :keyword:`!with` block raises an
-   :exc:`ExceptionGroup`, suppressed exceptions are removed from the
+   If the code within the :keyword:`!with` block raises a
+   :exc:`BaseExceptionGroup`, suppressed exceptions are removed from the
    group.  If any exceptions in the group are not suppressed, a group containing them is re-raised.
 
    .. versionadded:: 3.4
@@ -314,6 +314,10 @@ Functions and classes provided:
       ``suppress`` now supports suppressing exceptions raised as
       part of an :exc:`ExceptionGroup`.
 
+   .. versionchanged:: 3.12.1
+      ``suppress`` now supports suppressing exceptions raised as
+      part of an :exc:`BaseExceptionGroup`.
+
 .. function:: redirect_stdout(new_target)
 
    Context manager for temporarily redirecting :data:`sys.stdout` to

Lib/contextlib.py

@@ -461,7 +461,7 @@ def __exit__(self, exctype, excinst, exctb):
             return
         if issubclass(exctype, self._exceptions):
             return True
-        if issubclass(exctype, ExceptionGroup):
+        if issubclass(exctype, BaseExceptionGroup):
             match, rest = excinst.split(self._exceptions)
             if rest is None:
                 return True

Lib/test/test_contextlib.py

@@ -1297,6 +1297,10 @@ def test_exception_groups(self):
                 [KeyError("ke1"), KeyError("ke2")],
             ),
         )
+        # Check handling of BaseExceptionGroup, using GeneratorExit so that
+        # we don't accidentally discard a ctrl-c with KeyboardInterrupt.
+        with suppress(GeneratorExit):
+            raise BaseExceptionGroup("message", [GeneratorExit()])
 
 
 class TestChdir(unittest.TestCase):

Misc/NEWS.d/next/Library/2023-11-09-10-45-56.gh-issue-103791.sdfkja.rst

@@ -0,0 +1,3 @@
+:class:`contextlib.suppress` now supports suppressing exceptions raised as
+part of a :exc:`BaseExceptionGroup`, in addition to the recent support for
+:exc:`ExceptionGroup`.