python / python/cpython

missing attribute in handler shutdown

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Description

Bug report

Bug description:

My code uses the logging handler package (https://docs.python.org/3/library/logging.handlers.html). On closing, I was getting

Exception ignored in atexit callback <function shutdown at 0x0000017934F72770>:
Traceback (most recent call last):
File "...._init_.py", line 2244, in shutdown
if getattr(h, 'flushOnClose', True):
RuntimeError: wrapped C/C++ object of type QTextEditLogger has been deleted

'QTextEditLogger' being a child class of Handler:

class QTextEditLogger(Handler, QObject):
    appendPlainText = pyqtSignal(str)

    def __init__(self, parent):
        Handler.__init__(self) 
        QObject.__init__(self)
        ....

when the program closed.
I finally traced the problem back to the shutdown() function in the getLogger class.

       if h:
           try:
              h.acquire()
              # MemoryHandlers might not want to be flushed on close,
              # but circular imports prevent us scoping this to just
              # those handlers.  hence the default to True.
              if getattr(h, 'flushOnClose', True):
                  h.flush()
              h.close()

Not all handlers have the 'flushOnClose' attribute! So it throws an exception, as per the documentation, BTW, when getattr() is called and 'flushOnClose' isn't there.

The fix is simple, I added the hasattr() function to see if the attribute exists:

       **if hasattr(h, 'flushOnClose'):**                     
             if getattr(h, 'flushOnClose', True):
                h.flush()
        h.close()

CPython versions tested on:

3.14

Operating systems tested on:

Windows

Contributor guide

Open the contributing guide

First steps

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  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start in init.py around the shutdown() code shown in the report and inspect how handler cleanup behaves for the QTextEditLogger example on CPython 3.14. Reproduce the Windows shutdown traceback, then verify that the corrected cleanup path no longer raises the reported exception while preserving normal handler flushing and closing.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
tooling
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Quiet
Clarity
Mostly clear
Newbie friendliness
52/100

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