`utcnow` deprecation note is misleading

Documentation

Currently, the deprecation notice for datetime.utcnow() reads:

Deprecated since version 3.12: Use datetime.now() with UTC instead.

Unfortunately, applying this suggestion verbatim can easily break user code – especially when applying it to libraries. (See for example https://foss.heptapod.net/openpyxl/openpyxl/-/issues/2051). These datetime-related TypeErrors are easy to introduce, and fairly hard to fix. I suggest to amend the deprecation notice:

Deprecated since version 3.12: Use datetime.now(UTC) instead. Please note that this will return an aware datetime object. If you need to remain compatible, use datetime.now(UTC).replace(tzinfo=None).

Maybe someone can come up with a better wording.

Linked PRs

• gh-118571

查看链接的 datetime 页面中关于 datetime.datetime.utcnow() 的文档，并将拟议措辞与 PR gh-118571 进行比较。当 deprecation note 明确警告 datetime.now(UTC) 返回一个 aware datetime，并说明兼容性选项 replace(tzinfo=None)，或采用已达成一致的更好措辞时，即视为完成。