`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

查看連結的 datetime 頁面中關於 datetime.datetime.utcnow() 的文件，並將提議的措辭與 PR gh-118571 進行比較。當 deprecation note 明確警告 datetime.now(UTC) 會回傳一個 aware datetime，並說明相容性選項 replace(tzinfo=None)，或採用已達成共識的更佳措辭時，即視為完成。