gh-103791: Make contextlib.suppress also act on exceptions within an ExceptionGroup #103792
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ambv
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Apr 24, 2023
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- Issue: contextlib.suppress does not support ExceptionGroups #103791
…in an ExceptionGroup
| match, rest = excinst.split(self._exceptions) | ||
| if rest is None: | ||
| return True | ||
| raise rest |
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This isn't ideal as it makes the exception group's own traceback include the def __exit__(...) frame. For example:
File "/Volumes/RAMDisk/cpython/Lib/test/test_contextlib.py", line 1220, in test_exception_groups
with suppress(ValueError):
File "/Volumes/RAMDisk/cpython/Lib/contextlib.py", line 454, in __exit__
raise rest from excinst
File "/Volumes/RAMDisk/cpython/Lib/test/test_contextlib.py", line 1221, in test_exception_groups
raise eg_all()
in case of the newly added test.
This isn't a big problem because:
- the group's member exceptions contain pristine tracebacks, only the group itself contains extra frames; and
- the
raiseof the original group is still included in the traceback because we used.split()to create the new object.
Ideally, we wouldn't need this. However, the API of __exit__ makes it impossible to replace the ExceptionGroup instance with another one, while ExceptionGroup itself makes its exceptions read-only.
Misc/NEWS.d/next/Library/2023-04-24-23-07-56.gh-issue-103791.bBPWdS.rst
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Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com>
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When you're done making the requested changes, leave the comment: |
OK, GitHub indeed doesn't disable auto-merge when changes are requested
* main: pythongh-87729: add LOAD_SUPER_ATTR instruction for faster super() (python#103497) pythongh-103791: Make contextlib.suppress also act on exceptions within an ExceptionGroup (python#103792)
| return | ||
| if issubclass(exctype, self._exceptions): | ||
| return True | ||
| if issubclass(exctype, ExceptionGroup): |
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Was there a specific reason to handle ExceptionGroup but not BaseExceptionGroup?
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I doubt it. Want to make a PR?