[issue37913] Document that __length_hint__ may return NotImplemented

[Jeroen Demeyer]

New submission from Jeroen Demeyer <jeroen.k.demeyer at gmail.com>:

The special method __length_hint__ can return NotImplemented. In this case, the result is as if the __length_hint__ method didn't exist at all. This behaviour is implemented and tested but not documented.

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assignee: docs at python
components: Documentation
messages: 350180
nosy: docs at python, jdemeyer
priority: normal
severity: normal
status: open
title: Document that __length_hint__ may return NotImplemented
type: enhancement
versions: Python 3.7, Python 3.8, Python 3.9

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue37913>
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