Argparse error when inputting values

[bowlofred]

First, put your code inside python tags so it is easily readable (and so indentation can be seen).

Second, how are you running it? Are you giving an argument to -n? When I do I get a str error instead of a NoneType error.

You haven't told argparse that -n is required, so it will let you run without the argument. Also, the default is to read the argument as a string. So num_nums is a string and the print won't work when you ask it to format a string with %d.

You can modify the add_argument to resolve both. Something like

parser.add_argument("-n", type=int, required=True, help="Number to add")