[Python-Dev] Problems with GeneratorExit deriving from Exception

Georg Brandl g.brandl at gmx.net
Sun Dec 2 19:43:01 CET 2007

Antoine Pitrou schrieb:
> Hi,
> (I was asked to forward this from the bug tracker)
>> We have also run into problems where a task tries to "return" (yield Return())
>> from within a try: except Exception: block.  Since returning from a coroutine is
>> roughly equivalent to "raise GeneratorExit", the exception can be caught and
>> ignored, with the same consequences as above.
> I may be missing something but why don't you just catch StandardError
> instead? If I believe Python 2.5's exception hierarchy it would catch
> anything under Exception except for GeneratorExit, StopIteration and the
> various Warnings.

Problem is, many (most?) third-party modules derive their exceptions from
Exception, not StandardError, so you'd have to add special cases for them


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Four shall be the number of spaces thou shalt indent, and the number of thy
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