How can I pass a list as a command-line argument with argparse?

In Python's argparse module, you can pass a list as a command-line argument using the nargs or append options.

nargs

Use nargs to specify the number of arguments to expect. For example, nargs=' indicates one or more arguments, and nargs='*' indicates zero or more arguments. Here's how to use it:

parser.add_argument('-l', '--list', nargs=' ', help=' Set flag', required=True)
# Use like:
# python test.py -l 1234 2345 3456 4567

append

Use append to create a list by adding each argument as an element. Here's how to use it:

parser.add_argument('-l', '--list', action='append', help=' Set flag', required=True)
# Use like:
# python test.py -l 1234 -l 2345 -l 3456 -l 4567

IMPORTANT:

• Do not use type=list with argparse. It creates a list of lists which is not the desired behavior.
• When passing a list as an argument, avoid using quotes.