Docs: Fix some semantic usages of iterator.__iter__

[koyuki7w]

The reference to __iter__ method seems to mean object.__iter__, not iterator.__iter__.

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📚 Documentation preview 📚: https://cpython-previews--130172.org.readthedocs.build/

[picnixz]

In the iterator term, we have:

Iterator are required to have an :meth:`~iterator.__iter__` method that returns the iterator

which is correct. Can you check if there are other mentions to iterator.__iter__ when we actually mean object.__iter__?

[koyuki7w]

glossary.rst has three links to __iter__, and the remaining one refers to iterator.__iter__ correctly.

I also looked for some other files and found some incorrect links in library/abc.rst and library/stdtypes.rst.

[picnixz]

I hope we don't have more __iter__ usages. If you want, you can perhaps look at the other __iter__ usages that were actually iterator.__iter__ and not object.__iter__ or not !__iter__ and vice-versa?

[koyuki7w]

__iter__ is used in the following files:

glossary.rst
extending/newtypes.rst
howto/enum.rst
reference/expressions.rst
reference/datamodel.rst
tutorial/classes.rst
library/mailbox.rst
library/abc.rst
library/stdtypes.rst
library/zipfile.rst
library/unittest.rst
library/unittest.mock.rst
library/functions.rst
library/collections.abc.rst
library/unittest.mock-examples.rst

All of these usages are correct except as corrected in this PR.

(Some of them are container.__iter__, which is equivalent to object.__iter__.)

[miss-islington-app]

Thanks @koyuki7w for the PR, and @encukou for merging it 🌮🎉.. I'm working now to backport this PR to: 3.12, 3.13.
🐍🍒⛏🤖

[bedevere-app]

GH-130543 is a backport of this pull request to the 3.13 branch.

[bedevere-app]

GH-130544 is a backport of this pull request to the 3.12 branch.