Checking the number of command line arguments in python

Question

I\'m new to python. Still getting my feet wet. I\'m trying to do something like this:

import sys

if ((len(sys.argv) < 3 or < len(sys.argv > 3)):
             


        

Answer 1

Use sys.exit() to exit from a script.

import sys

if len(sys.argv) != 3:
    print """\
This script will compare two files for something
and print out matches

Usage:  theScript firstfile secondfile
"""
    sys.exit(0)

Answer 2

sys has a function called exit:

sys.exit(1)

is probably what you want. Using 1 tells the program calling your program that there was an error. You should probably consider writing to sys.stderr the reason for the error.