Monty Hall Problem

monty.py

import argparse
from random import random
from fractions import Fraction


def monty(change=True):
    right = 1
    x = random()
    if x <= Fraction(1 / 3):
        answer = 1
        wrong = 2
    elif x <= Fraction(2 / 3):
        answer = 2
        wrong = 3
    else:
        answer = 3
        wrong = 2

    if change:
        answer = 6 - answer - wrong

    if right == answer:
        return True
    else:
        return False


if __name__ == '__main__':
    parser = argparse.ArgumentParser(description="Simulate Monty Hall Problem")
    parser.add_argument("-n", "--num", type=int, help="number of iteration")
    args = parser.parse_args()
    n = 1000
    if args.num:
        n = args.num
    cnt = sum([1 for i in range(n) if monty(change=True)])
    print("Change: ", cnt / n)

    cnt = sum([1 for i in range(n) if monty(change=False)])
    print("Not change: ", cnt / n)