diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst index a03d88092dbf1f..7447395947d530 100644 --- a/Doc/library/argparse.rst +++ b/Doc/library/argparse.rst @@ -1156,16 +1156,20 @@ if the argument was not one of the acceptable values:: game.py: error: argument move: invalid choice: 'fire' (choose from 'rock', 'paper', 'scissors') -Note that inclusion in the *choices* sequence is checked after any type_ -conversions have been performed, so the type of the objects in the *choices* -sequence should match the type_ specified. - Any sequence can be passed as the *choices* value, so :class:`list` objects, :class:`tuple` objects, and custom sequences are all supported. Use of :class:`enum.Enum` is not recommended because it is difficult to control its appearance in usage, help, and error messages. +Note that *choices* are checked after any type_ +conversions have been performed, so objects in *choices* +should match the type_ specified. This can make *choices* +appear unfamiliar in usage, help, or error messages. + +To keep *choices* user-friendly, consider a custom type wrapper that +converts and formats values, or omit type_ and handle conversion in +your application code. Formatted choices override the default *metavar* which is normally derived from *dest*. This is usually what you want because the user never sees the *dest* parameter. If this display isn't desirable (perhaps because there are