Writing a help for python script

Best practice is to use argparse to handle all your commandline arguments. It includes a default --help which you can customize to your likings.

Here's the simplest example:

import argparse

parser = argparse.ArgumentParser(description='This is my help')

args = parser.parse_args()

Which results in:

% python argparse_test.py -h
usage: argparse_test.py [-h]

This is my help

optional arguments:
  -h, --help  show this help message and exit

You can define all your arguments with argparse and set a help message for each one of them. The resulting filtered/validated arguments are returned by parser.parse_args().

Use argparse.

For example, with test.py:

import argparse

parser=argparse.ArgumentParser(
    description='''My Description. And what a lovely description it is. ''',
    epilog="""All is well that ends well.""")
parser.add_argument('--foo', type=int, default=42, help='FOO!')
parser.add_argument('bar', nargs='*', default=[1, 2, 3], help='BAR!')
args=parser.parse_args()

Running

% test.py -h

yields

usage: test.py [-h] [--foo FOO] [bar [bar ...]]

My Description. And what a lovely description it is.
    
positional arguments:
  bar         BAR!
    
optional arguments:
  -h, --help  show this help message and exit
  --foo FOO   FOO!
    
All is well that ends well.