bpo-41024: doc: Explicitly mention use of 'enum.Enum' as a valid container for '… (GH-20964)
…choices' argument of 'argparse.ArgumentParser.add_argument'.
Here's a short first proposal of doc. enhancement addressing [bpo-41024]().
Automerge-Triggered-By: @csabella
diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst
index 5e0096c..0b64dfe 100644
--- a/Doc/library/argparse.rst
+++ b/Doc/library/argparse.rst
@@ -1133,6 +1133,20 @@
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'>)
required