My view of this is: A. It's not an iterator if it doesn't define `__next__`. B. It is strongly recommended that iterators also define `__iter__`. In "standards" language, I think (A) is MUST and (B) is merely OUGHT or maybe SHOULD. On Tue, Sep 14, 2021 at 12:30 PM Brett Cannon <brett@python.org> wrote:
Over in https://github.com/python/typeshed/issues/6030 I have managed to kick up a discussion over what exactly an "iterator" is. If you look at https://docs.python.org/3/library/functions.html#iter you will see the docs say it "Return[s] an iterator <https://docs.python.org/3/glossary.html#term-iterator> object." Great, but you go the glossary definition of "iterator" at https://docs.python.org/3/glossary.html#term-iterator you will see it says "[i]terators are required to have an __iter__() <https://docs.python.org/3/reference/datamodel.html#object.__iter__> method" which neither `for` nor `iter()` actually enforce.
Is there something to do here? Do we loosen the definition of "iterator" to say they *should* define __iter__? Leave it as-is with an understanding that we know that it's technically inaccurate for iter() but that we want to encourage people to define __iter__? I'm assuming people don't want to change `for` and `iter()` to start requiring __iter__ be defined if we decided to go down the "remove the __aiter__ requirement" from aiter() last week.
BTW all of this applies to async iterators as well. _______________________________________________ Python-Dev mailing list -- python-dev@python.org To unsubscribe send an email to python-dev-leave@python.org https://mail.python.org/mailman3/lists/python-dev.python.org/ Message archived at https://mail.python.org/archives/list/python-dev@python.org/message/3W7TDX5K... Code of Conduct: http://python.org/psf/codeofconduct/
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