bpo-42501: Revise the usage note for Enums with the choices (pythonGH…

…-23563)

Doc/library/argparse.rst

@@ -1133,20 +1133,9 @@ container should match the type_ specified::
 
 Any container can be passed as the *choices* value, so :class:`list` objects,
 :class:`set` objects, and custom containers are all supported.
-This includes :class:`enum.Enum`, which could be used to restrain
-argument's choices; if we reuse previous rock/paper/scissors game example,
-this could be as follows::
-
-   >>> from enum import Enum
-   >>> class GameMove(Enum):
-   ...     ROCK = 'rock'
-   ...     PAPER = 'paper'
-   ...     SCISSORS = 'scissors'
-   ...
-   >>> parser = argparse.ArgumentParser(prog='game.py')
-   >>> parser.add_argument('move', type=GameMove, choices=GameMove)
-   >>> parser.parse_args(['rock'])
-   Namespace(move=<GameMove.ROCK: 'rock'>)
+
+Use of :class:`enum.Enum` is not recommended because it is difficult to
+control its appearance in usage, help, and error messages.
 
 
 required