Python Programming

If you look at the documentation (you still have it open, do you not? 😀), ArgumentParser.add_argument() also provides the nargs keyword argument.

This allows you to specify how many values each argument is expecting. Note that argparse will return a list for an argument when you specify nargs.

Here are the available options:

• nargs=N: returns a list of N arguments
• nargs="?": returns zero or one argument (i.e. optional)
• nargs="*": returns a list of zero or more arguments
• nargs="+": returns a list of one or more arguments
• nargs=argparse.REMAINDER: returns a list from the remainding arguments

Try playing around with these, and examine the output yourself! Try adding multiple arguments or mixing positional and optional arguments too, to see how argparse behaves with multiple arguments (it is actually pretty smart!)

parser.add_argument("a", nargs=3)
parser.add_argument("b", nargs="?")
parser.add_argument("c", nargs="*")
parser.add_argument("d", nargs="+")
parser.add_argument("e", nargs=argparse.REMAINDER)