argparse module handles argument parsement out of global variable sys.argv. It can also generate help and error messages if the user gives invalid arguments. argparse module located at "Lib/argparse.py".

Let's see a file named "test.py" with code:

import argparse
ps = argparse.ArgumentParser()
ps.add_argument('--elements',help='strings to be concatenated')
args = ps.parse_args()

C:\> python test.py --help

usage: test.py [-h] [--elements ELEMENTS]
optional arguments:
-h, --help show this help message and exit
--elements ELEMENTS strings to be concatenated