python - How to Check if an Argument Was Called Without an Action? -

i want able see if argument called without using store action. instead of code looking this:

parser = argparse.argumentparser()  parser.add_argument('-a', '--argument', action="store", dest="some_arg",     help='help data..', default="none")  args = parser.parse_args()  if args.some_arg == "user input":     print "argument called." 

i want user not have enter in "user input" same result print "argument called". in other words if user wanted reference argument have type:

script.py --argument 

instead of:

script.py --argument user input 

you can use store_true action. set value true if argument specified, or false otherwise:

parser = argparse.argumentparser() parser.add_argument('--foo', action='store_true')  args = parser.parse_args() if args.foo:     print('--foo specified')