Coinflip!

coinflip.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Takes an arbitrary number of command line arguments and randomly selects one
to return. The amount of entropy involved can be adjusted by setting the
environment variable ```RANDBYTES```, which defaults to 4096.
"""

from __future__ import print_function

import os
import sys
import random

RANDBYTES = int(os.environ.get('RANDBYTES', 4096))


def coinflip(*args):
    random.seed(os.urandom(RANDBYTES))
    return random.choice(list(args))

if __name__ == '__main__':
    try:
        print(coinflip(*sys.argv[1:]))
    except IndexError:
        print("coinflip: usage: coinflip OPTIONS...")