locale module example is wrong for some platforms

[smarie]

BPO	47187
Nosy	@smarie

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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assignee = None
closed_at = None
created_at = <Date 2022-04-01.13:45:07.191>
labels = ['3.10', 'docs']
title = 'locale module example is wrong for some platforms'
updated_at = <Date 2022-04-01.13:45:07.191>
user = 'https://github.com/smarie'

bugs.python.org fields:

activity = <Date 2022-04-01.13:45:07.191>
actor = 'smarie'
assignee = 'docs@python'
closed = False
closed_date = None
closer = None
components = ['Documentation']
creation = <Date 2022-04-01.13:45:07.191>
creator = 'smarie'
dependencies = []
files = []
hgrepos = []
issue_num = 47187
keywords = []
message_count = 1.0
messages = ['416487']
nosy_count = 2.0
nosy_names = ['docs@python', 'smarie']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = None
url = 'https://bugs.python.org/issue47187'
versions = ['Python 3.10']

[smarie]

The example in the doc shows

>>> import locale
>>> loc = locale.getlocale()  # get current locale
# use German locale; name might vary with platform
>>> locale.setlocale(locale.LC_ALL, 'de_DE')
>>> locale.strcoll('f\xe4n', 'foo')  # compare a string containing an umlaut
>>> locale.setlocale(locale.LC_ALL, '')   # use user's preferred locale
>>> locale.setlocale(locale.LC_ALL, 'C')  # use default (C) locale
>>> locale.setlocale(locale.LC_ALL, loc)  # restore saved locale

However locale.getlocale() does not return the locale for all categories (locale.LC_ALL is even not allowed) but the locale for the LC_CTYPE category.

Therefore restoring it using locale.setlocale(locale.LC_ALL, loc) does not actually restore the initial settings, and may even fail on some platforms (on mine it does).

The correct example should have the first line of code replaced with

>>> loc = locale.setlocale(locale.LC_ALL)  # get current locale

Note: this issue was first reported in the pandas library at pandas-dev/pandas#46595