3 ms·

That turned out to be not that great of an idea, and it's changed in Python 3.5: https://www.python.org/dev/peps/pep-0479/ https://www.python.org/dev/peps/pep-0

• dalke 11y ago
  That's not a change to the iterator protocol. It's a change to 'StopIteration handling inside generators'. The following will still raise a StopIteration in Python 3.5+: >>> next(iter([]))
  • pvg 11y ago
    Yep, the fundamental termination mechanism seems to be the same. Years and years ago I got into some silly irc nerdgument with a python expert (I think one of the twisted people) about the ugliness of this design and for a moment I thought I got to triumphantly yell 'Told you so!' a decade later. Alas, not the case.
    • dalke 11y ago
      I take it you prefer the explicit test for the end of iteration? As an historic note, the StopIteration form grew out of the earlier iterator form, which called __getitem__ with successive integers until there was an IndexError. That may explain a bias towards an exception-based approach.
      • pvg 11y ago
        I probably do, although in practice, given how well (and composable) python comprehensions/iterators/generators have turned out, getting all worked up about some implementation detail now seems a bit churlish and pointless.