Juraj: Is the example behavior from Py2 or Py3? The meaning of 'range' changed. In Py2, xrange would be the correct choice for 'choice'.

Does argparse actually convert (x)range objects to a list or set (the help indicates the latter) for internal use? That would be foolish as 'n in <range>' is an O(1) operation. (I don't remember is that works for xrange.) For instance, range(0, 1000, 2) is a nice way to say 'even count less than 1000'.

If it is not so converted, converting for display is also foolish.
'range(0, 1000, 2)' is clearer than an explicit sequence.