On Thu, 16 Sept 2021 at 01:30, Chris Barker via Python-Dev <python-dev@python.org> wrote: > """ > "[i]terators are required to have an __iter__() method" which neither `for` > nor `iter()` actually enforce. > """ > > I'm confused -- as far as I can tell `for` does enforce this -- well, it > doesn't enforce it, but it does require it, which is the same thing, yes? But > does it need to?
for enforces that *iterables* have an __iter__ method, not *iterators*. (for takes an iterable, not an iterator, and uses __iter__ to *get* an iterator from it). The debate here is (I think!) whether an *iterator* that is not also an *iterable* is a valid iterator. IMO it is valid (because that's what the definitions say, basically) but it may not be *useful* in certain circumstances, and it definitely may not be *expected* (because nearly all iterators are iterables). "Broken" is a strong word to use, though, and that might be why the debate is continuing this long... Paul _______________________________________________ Python-Dev mailing list -- python-dev@python.org To unsubscribe send an email to python-dev-le...@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/UIKBKWT5G4ME2LVZ3W6RYRK5ESNBEZBQ/ Code of Conduct: http://python.org/psf/codeofconduct/
