Appending blocks of text to argparse help message

appending-text-to-help-example.py

""" An example of appending blocks to a help message. """

import argparse
import sys


TEXT_TO_APPEND = """
examples:
    This is how you do things

notes:
    Lots of notes
""".strip()


def display_help_and_exit(parser):
    parser.print_help()
    print(TEXT_TO_APPEND)
    exit(0)


class DisplayHelp(argparse.Action):
    def __call__(self, parser, *args, **kwargs):
        display_help_and_exit(parser)


parser = argparse.ArgumentParser(add_help=False)

parser.add_argument("myarg", help="the arg")
parser.add_argument("-h", "--help", nargs=0, action=DisplayHelp)
args = parser.parse_args()

if len(sys.argv) <= 1:
    display_help_and_exit(parser)