Generate a random password with a given problem space complexity.

generate-complex-passphrase.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

from math import ceil, log
from string import ascii_lowercase, ascii_uppercase, digits

# use system random
from random import SystemRandom
random = SystemRandom()

lookalikes = "1lI0O"

passphrase_chars = ''.join(filter(lambda a: a not in lookalikes,
                           ascii_lowercase + ascii_uppercase + digits))


def main():
    problem_space = 192  # bits
    min_digits = ceil(log(2**problem_space, len(passphrase_chars)))

    passphrase = ''.join([random.choice(passphrase_chars) for i in
                          range(min_digits)])

    print("{}: {}".format(min_digits, passphrase))


if __name__ == "__main__":
    main()