Monty Hall Problem

monty_hall_simul.py

"""
https://en.wikipedia.org/wiki/Monty_Hall_problem
"""

import random


def do_game(change_selection):
    # Initial door
    doors = [1, 0, 0]
    random.shuffle(doors)

    # Select one
    selection = random.randint(0, 2)

    # Host lets the participant know
    _ones = [x for x in range(3) if x != selection]
    wrong_one = _ones[0] if doors[_ones[0]] == 0 else _ones[1]
    left_ones = [x for x in range(3) if x != wrong_one]

    # Do the condition
    if change_selection:
        selection = [x for x in left_ones if x != wrong_one][0]

    # Check answer
    if doors[selection] == 1:
        return True
    else:
        return False

a = 0
b = 0

for _ in xrange(100000):
    a += do_game(True)
    b += do_game(False)

print 'When you select the other one:', a
print 'When you don\'t:', b

print 'Ratio: ', 1.0 *  a / (a + b) # This will give you roughly about 0.6xx
print 'Ratio: ', 1.0 *  b / (a + b) # This will give you roughly about 0.3xx