The logging.Logger.warn() method was deprecated in Python 3.3 by issue #57444 and commit 04d5bc0. This method is not documented and emits a DeprecationWarning since Python 3.3.

#57444 (comment):

That's deliberate. The original code (before incorporation into Python) had warn(), which was kept for backward compatibility. The docs refer to warning() because that's what everyone is supposed to use. The method names map to the lower case of the appropriate logging level name.

I propose to remove this logging.Logger.warn() method in Python 3.13.

Linked PRs

• gh-105376: Remove logging.Logger.warn() method #105377
• gh-105376: Remove logging.warn() and LoggerAdapter.warn() #106553
• gh-105376: Restore deprecated logging warn() method #122775
• [3.13] gh-105376: Restore deprecated logging warn() method (GH-122775) #122856