how to command a line in python code example

Example 1: pass argument to a py file

import sys

def hello(a,b):
    print "hello and that's your sum:", a + b

if __name__ == "__main__":
    a = int(sys.argv[1])
    b = int(sys.argv[2])
    hello(a, b)
# If you type : py main.py 1 5
# It should give you "hello and that's your sum:6"

Example 2: run python with options

import argparse
import sys

parser = argparse.ArgumentParser(description="Does some awesome things.")
parser.add_argument('message', type=str, help="pass a message into the script")

if __name__ == '__main__':
    args = parser.parse_args(sys.argv[1:])
    print args.message

Example 3: python main args

#!/usr/bin/python

import sys, getopt

def main(argv):
   inputfile = ''
   outputfile = ''
   try:
      opts, args = getopt.getopt(argv,"hi:o:",["ifile=","ofile="])
   except getopt.GetoptError:
      print 'test.py -i <inputfile> -o <outputfile>'
      sys.exit(2)
   for opt, arg in opts:
      if opt == '-h':
         print 'test.py -i <inputfile> -o <outputfile>'
         sys.exit()
      elif opt in ("-i", "--ifile"):
         inputfile = arg
      elif opt in ("-o", "--ofile"):
         outputfile = arg
   print 'Input file is "', inputfile
   print 'Output file is "', outputfile

if __name__ == "__main__":
   main(sys.argv[1:])