Monty Hall Problem Simulation

monty_hall.py

import random
import sys


def monty_hall(choice, switch):
    '''
    @param
    :choice: - int between 1 and 3.
    :switch: - boolean. Switches choice if true.
    '''
    wins, losses = 0, 0

    # Random suffle of the doors.
    doors = ["goat", "goat", "car"]
    random.shuffle(doors)

    # Show one of the goats.
    goat_door = 0
    for i in range(3):
        if doors[i-1] == "goat" and choice != i:
            goat_door = i

    # Switch the option if the "switch" is passed as True
    if(switch):
        n = {1, 2, 3} - {choice, goat_door}
        choice = n.pop()

    # Final reveal
    if doors[choice-1] == "goat":
        return False
    else:
        return True


ITERATIONS = 10000

if __name__ == "__main__":

    if len(sys.argv) == 2:
        ITERATIONS = int(sys.argv[1])
    no_switch_wins = 0
    no_switch_losses = 0
    switch_wins = 0
    switch_losses = 0

    # Play the Monty Hall game $ITERATIONS times.
    for i in range(ITERATIONS):
        choice = random.randrange(3)
        if(monty_hall(choice, True)):
            switch_wins += 1
        else:
            switch_losses += 1

        if(monty_hall(choice, False)):
            no_switch_wins += 1
        else:
            no_switch_losses += 1
            
    # Output
    print("\nNo switch data:")
    print("   - WINS   : " + str(no_switch_wins))
    print("   - LOSSES : " + str(no_switch_losses))
    print("Switch data:")
    print("   - WINS   : " + str(switch_wins))
    print("   - LOSSES : " + str(switch_losses))
    print("Total games played : " + str(ITERATIONS))