numerical solution of the monty hall problem

monty.py

import random

GOAT = 0
CAR = 1
TRIALS = 10**4

def run_trial(switch=False):
    choice = random.randint(0,2)
    doors = [GOAT, GOAT, CAR]
    random.shuffle(doors)

    if switch:
        return not doors[choice] and CAR or GOAT
    else:
        return doors[choice]

def run_trials(switch=False):
    wins = sum(run_trial(switch) for _ in range(TRIALS))
    return wins / TRIALS

print("Probability of winning when not switching: {:.3f}".format(run_trials(switch=False)))
print("Probability of winning when switching: {:.3f}".format(run_trials(switch=True)))