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Author gvanrossum
Recipients Rosuav, gvanrossum, python-dev, schlamar
Date 2014-11-21.18:11:13
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If all examples were just using "raise StopIteration" instead of "return"
in a generator I would be very happy. Such code can be trivially fixed by
using "return" and the __future__ import will help the eventual transition.

It's sad that apparently this use of return hasn't been better advertised
-- it has existed since generators were first introduced.

On Fri, Nov 21, 2014 at 9:44 AM, Chris Angelico <>

> Chris Angelico added the comment:
> Yep, the question is whether any of the "raise StopIteration" lines are
> actually non-local flow control. If they're local, then it's easy:
> mechanical replacement with "return" and it becomes compatible with all
> versions (unless it has a value attached to it, as "return x" doesn't work
> in Py2). But if they're non-local, some refactoring will need to be done.
> In any case, my line of argument is: A generator function is not an
> iterator's __next__ method, ergo iterator protocol does not apply. Use of
> StopIteration is a hack that happens to work because of how generator
> functions are implemented (a thin wrapper around an iterator), but it's not
> part of the *concept* of a generator function.
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Date User Action Args
2014-11-21 18:11:13gvanrossumsetrecipients: + gvanrossum, python-dev, schlamar, Rosuav
2014-11-21 18:11:13gvanrossumlinkissue22906 messages
2014-11-21 18:11:13gvanrossumcreate