[Python-Dev] Revert #12085 fix for __del__ attribute error message
tjreedy at udel.edu
Sun Sep 22 01:55:05 CEST 2013
On 9/21/2013 6:15 PM, R. David Murray wrote:
> On Sat, 21 Sep 2013 17:16:41 -0400, Terry Reedy <tjreedy at udel.edu> wrote:
>> When an AttributeError is raised in a __del__ method, it is caught and
>> ignored, except that it is not completely ignored but is replaced by a
>> warning message sent to stderr. Example:
>> >>> class C():
>> def __del__(self): raise AttributeError
>> >>> c=C()
>> >>> del c
>> Exception AttributeError: AttributeError() in <bound method C.__del__ of
>> <__main__.C object at 0x000000000351A198>> ignored
> This is a replacement for a traceback. In later Python versions, the
> full traceback is printed.
The above is 3.3.2. In 3.4.0a2, the traceback of the ignored exception
is indeed printed.
Exception ignored in: <bound method C.__del__ of <__main__.C object at
Traceback (most recent call last):
File "<pyshell#0>", line 2, in __del__
> In the general case it represents a bug in
> the code that should be fixed. Most such errors arise from the vagaries
> of module finalization (such as your issue 19021),
Lets call that a buglet ;-). Not really harmful, but annoying. Accepting
that even such buglets 'should' be fixed in the stdllib, so that the
message does not appear, is there any reason *not* to make it a
RuntimeWarning so that users who care about clean output can filter it
out while waiting for us to fix it?
This would be a separate issue from #12085.
> but not all of them
> do: the rest represent real bugs in __del__ methods (which are executed
> asynchronously in the general case).
Which is why the message should be printed, so the developer can decide.
Terry Jan Reedy
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