randpwd

#!/usr/bin/env python

import secrets, string, argparse

def parse_args():
    parser = argparse.ArgumentParser(
                 description='Create a random password using a secure RNG.',
                 formatter_class=argparse.ArgumentDefaultsHelpFormatter
             )
    parser.add_argument('--nchars', type=int, default=16, 
                        help='Number of characters to use for the password. The minimum is 14.')
    parser.add_argument('--special_chars', type=str, default='', 
                        help='A string of special characters to add to the alphabet. Put single quotes around it in case of any issues.')
    parser.add_argument('--include_all_chars', action='store_true', 
                        help='Include even characters like 1, l, I, L, o, O and 0 that are easily confused with each other in the alphabet.')
    args = parser.parse_args()

    if args.nchars < 14:
        print('Using fewer than 14 characters will result in an insecure password.')
        exit()

    a = string.ascii_letters + string.digits + args.special_chars
    if not args.include_all_chars:
        for c in '1lILoO0':
            a = a.replace(c, '')
        
    return a, args.nchars


if __name__ == '__main__':
    alphabet, nchars = parse_args()
    print(''.join(secrets.choice(alphabet) for _ in range(nchars)))