A trivial example, consuming one command line argument

#!/usr/bin/env python
"""
one command line argument is consumed
"""
import argparse

def main():

    parser = argparse.ArgumentParser( 
        formatter_class = argparse.RawDescriptionHelpFormatter,
        usage='%(prog)s [options]')
    
    parser.add_argument( 'hostName', nargs="?", default = "None", help='hostname to check')  
    args = parser.parse_args()
        
    if args.hostName != 'None':
        nodes = [args.hostName]
    else:
        nodes = ...
...