[docs] [issue37145] collections.abc.MappingView mixins rely on undocumented _mapping

[Geoffrey Sneddon]

New submission from Geoffrey Sneddon <geoffers+pythonbugs at gmail.com>:

The mixin methods on MappingView and its subclasses all rely on the undocumented MappingView._mapping (set in the undocumented MappingView.__init__).

This should probably be documented at least insofar as Set._from_iterable is.

----------
assignee: docs at python
components: Documentation
messages: 344447
nosy: docs at python, gsnedders
priority: normal
severity: normal
status: open
title: collections.abc.MappingView mixins rely on undocumented _mapping
type: behavior
versions: Python 2.7, Python 3.5, Python 3.6, Python 3.7, Python 3.8, Python 3.9

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue37145>
_______________________________________