[Python-Dev] Re: anonymous blocks (original) (raw)

Guido van Rossum gvanrossum at gmail.com
Wed Apr 27 23:57:01 CEST 2005

If the iterator fails to re-raise the StopIteration exception (the spec only says it should, not that it must) I think the return would be ignored but a subsquent exception would then get converted into a return value. I think the flag needs reset to avoid this case.

Good catch. I've fixed this in the PEP.

Also, I wonder whether other exceptions from next() shouldn't be handled a bit differently. If BLOCK1 throws an exception, and this causes the iterator to also throw an exception then one exception will be lost. I think it would be better to propogate the original exception rather than the second exception.

I don't think so. It's similar to this case:

try:
    raise Foo
except:
    raise Bar

Here, Foo is also lost.

-- --Guido van Rossum (home page: http://www.python.org/~guido/)

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