[Python-Dev] PEP 340: Deterministic Finalisation (new PEP draft, either a competitor or update to PEP 340)

[Delaney, Timothy C (Timothy)]

Greg Ewing wrote:

> Nick Coghlan wrote:
>> Hmm, with that approach, a code inspection tool like pychecker could
>> be used to pick up the slack, and flag generators which have a yield
>> inside a try/finally or a user defined statement without applying
>> the "needs finalisation" decorator 
> 
> What about giving them an __exit__ method if and only
> if they have a yield inside a try/finally? Old generators
> won't be doing that, because it's currently illegal.

It's possible to create a generator that does not contain a finally, but
still needs cleanup.

    def gen():
        try:
            yield
        except:
            print 'cleanup'
            raise

Tim Delaney