import argparse
parser = argparse.ArgumentParser()
parser.add_argument("argumentName", help="display help msg", type=int) # no --
parser.add_argument("-v","--verbosity", help="increase output verbosity", action="store_true") # with --
args = parser.parse_args()
if args.argumentName:
	# do sth
elif args.verbosity:
	print("verbosity turned on")
  • action="store_true" This means that, if the option is specified, assign the value True to args.verbose. Not specifying it implies False.
  • action="count" to count the number of the argument. eg: -vvv, use with default=0

Sub-command Parser

argparse — Parser for command-line options, arguments and sub-commands — Python 3.10.6 documentation
Many programs split up their functionality into a number of sub-commands, for example, the svn program can invoke sub-commands like svn checkoutsvn update, and svn commit. Splitting up functionality this way can be a particularly good idea when a program performs several different functions which require different kinds of command-line arguments. ArgumentParser supports the creation of such sub-commands with the add_subparsers() method. The add_subparsers() method is normally called with no arguments and returns a special action object. This object has a single method, add_parser(), which takes a command name and any ArgumentParser constructor arguments, and returns an ArgumentParser object that can be modified as usual.

  • action
  • dest
  • help
  • default
  • nargs