gistfile1.py

import random
import sys

from itertools import product

def random_monty(choices):
    return random.choice(choices)

def deterministic_monty(choices):
    return random.choice([c for c in choices if c != 0])

def switch_contestant(init, reveal):
    return init != 0

def stay_contestant(init, reveal):
    return init == 0

def rand_contestant(init, reveal):
    return random.choice([c for c in xrange(3) if c != reveal]) == 0

def game(monty, contestant):
    choices = [0,1,2]
    init = random.choice(choices)
    choices.remove(init)
    reveal = monty(choices)
    if reveal == 0:
        return game(monty, contestant)
    return contestant(init, reveal)

n = int(sys.argv[1])

montys = [('Random Monty', random_monty),
          ('Deterministic Monty', deterministic_monty)]

contestants = [('Switching contestant', switch_contestant),
               ('Stubborn contestant', stay_contestant),
               ('Random contestant', rand_contestant)]

for (md, monty), (cd, cont) in product(montys, contestants):
    k = 0
    for _ in xrange(n):
        if game(monty, cont):
            k += 1
    print '%s, %s: %.2f%%' % (md, cd, float(k) / n * 100)