arg parser

argparser.py

import argparse
parser = argparse.ArgumentParser()
parser.add_argument("square", type=int,
                    help="display a square of a given number")
parser.add_argument("-v", "--verbosity", action="count", default=0,
                    help="increase output verbosity")
args = parser.parse_args()
answer = args.square**2
if args.verbosity >= 2:
    print "the square of {} equals {}".format(args.square, answer)
elif args.verbosity >= 1:
    print "{}^2 == {}".format(args.square, answer)
else:
    print answer

output

➜  ~  python test.py 4 -v 1
4^2 == 16
➜  ~  python test.py 4 -v 2
the square of 4 equals 16
➜  ~  python test.py 4 -v 3
16
➜  ~  python test.py -h    
usage: test.py [-h] [-v {1,2,3}] square

positional arguments:
  square                display a square of a given number

optional arguments:
  -h, --help            show this help message and exit
  -v {1,2,3}, --verbosity {1,2,3}
                        increase output verbosity