Python argparse.ArgumentParser sample

class-commands.py

import sys
import argparse


class Command:
    def __init__(self, args):
        parser = argparse.ArgumentParser(description='class sample')
        parser.add_argument('--main', '-m', action='store_true', help='main command from class')
        self.parser = parser
        try:
            self.args = parser.parse_args(args)
        except argparse.ArgumentError:
            sys.exit(1)

first-command.py

import argparse

# usage
# $ python sample.py --main
# main command

parser = argparse.ArgumentParser(description='original command')
parser.add_argument('--main', '-m', action='store_true', help='main command')
args = parser.parse_args()

if args.main:
    print(f'main command')

sub-command.py

import argparse

parser = argparse.ArgumentParser(description='original command')
parser.add_argument('--main', '-m', action='store_true', help='main command')

subparsers = parser.add_subparsers()
parser_sub = subparsers.add_parser('sub', help='sub command')
parser_sub.add_argument('--a', '-a', action='store_true', help='sub command')
parser_sub.add_argument('--b', '-b', metavar='msg', help='message')

args = parser.parse_args()
if args.main:
    # usage
    # $ python sample.py --main
    # main command
    print(f'main command')

if args.a:
    # usage
    # $ python sample.py sub -a
    # sub True
    print(f'sub command a: {args}')

if args.b:
    # usage
    # $ python sample.py sub -b sample
    # sub command b: sample
    print(f'sub command b: {args.b}')