[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Antoine Pitrou added the comment: This is all fixed in the Python 3 branches now. I won't bother with Python 2 as it has quite a different code structure and backporting would take too much of my time. Pox TheGreat, thanks for reporting and the initial patch! --

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Antoine Pitrou added the comment: New changeset 069b8d20be8018fbd49ed5aaf64c4caba311e48f by Antoine Pitrou in branch '3.6': [3.6] bpo-31804: Fix multiprocessing.Process with broken standard streams (GH-6079) (GH-6081)

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Antoine Pitrou added the comment: New changeset ff5d21331ec6cefec6ba5b78d256d8dbcd67a069 by Antoine Pitrou (Miss Islington (bot)) in branch '3.7': bpo-31804: Fix multiprocessing.Process with broken standard streams (GH-6079) (GH-6080)

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Change by Antoine Pitrou : -- versions: +Python 3.8 -Python 2.7 ___ Python tracker ___ ___

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Change by Antoine Pitrou : -- pull_requests: +5842 ___ Python tracker ___ ___

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Change by miss-islington : -- pull_requests: +5841 ___ Python tracker ___

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Antoine Pitrou added the comment: New changeset e756f66c83786ee82f5f7d45931ae50a6931dd7f by Antoine Pitrou in branch 'master': bpo-31804: Fix multiprocessing.Process with broken standard streams (#6079)

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Change by Antoine Pitrou : -- superseder: multiprocessing.Process depends on sys.stdout being open -> ___ Python tracker ___

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Change by Antoine Pitrou : -- pull_requests: +5840 ___ Python tracker ___ ___

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Change by Roundup Robot : -- pull_requests: +5325 stage: resolved -> patch review ___ Python tracker ___

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Pox TheGreat added the comment: I have already uploaded a patch file but it is not in the required format. Also I realize that most of the confusion was because I forgot to provide the OS version. Perhaps it would be good to have a separate field for that. I will

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Antoine Pitrou added the comment: I'm not using Windows, so I'm unable to test using pythonw. You'll have to provide a fix, or someone else will have to. -- ___ Python tracker

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Pox TheGreat added the comment: Retested it with a freshly installed 3.6.4 version. Used the following code to test: import sys import multiprocessing def foo(): return 'bar' if __name__ == '__main__': proc = multiprocessing.Process(target=foo)

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Terry J. Reedy added the comment: Pox, please retest with either 3.6.4 or 3.7.0a3 (or .0a4 when released, soon). Both were released after the merge that should fix this. -- ___ Python tracker

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Antoine Pitrou added the comment: @Pox, nevertheless, the fix committed in https://github.com/python/cpython/pull/4073 should also fix this issue. Do you disagree? -- ___ Python tracker

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Pox TheGreat added the comment: Unfortunately this is NOT a duplicate of https://bugs.python.org/issue28326. That issue is about a closed output stream. In that case sys.stdout and sys.stderr are file like objects which have been closed. This issue is about sys.stdout

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Antoine Pitrou added the comment: This looks to be a duplicate of https://bugs.python.org/issue28326 -- resolution: -> duplicate stage: -> resolved status: open -> closed superseder: -> multiprocessing.Process depends on sys.stdout being open

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Change by Terry J. Reedy : -- versions: +Python 2.7, Python 3.6, Python 3.7 -Python 3.5 ___ Python tracker ___

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

Change by Terry J. Reedy : -- nosy: +davin, pitrou, terry.reedy ___ Python tracker ___ ___

[issue31804] multiprocessing calls flush on sys.stdout at exit even if it is None (pythonw)

New submission from Pox TheGreat : If you start Python by pythonw then sys.stdout and sys.stderr are set to None. If you also use multiprocessing then when the child process finishes BaseProcess._bootstrap calls sys.stdout.flush() and sys.stderr.flush() finally. This