<human>:  Python's argparse to show program's version with prog and version string formatting
<bot>: Here is some code to argparse add argument with flag '--version' and version action of '%(prog)s 2.0' to parser `parser`

parser.add_argument('--version', action='version', version='%(prog)s 2.0')

#Warning: this code generation is experimental. Please inspect the code for any bugs before executing.