Monty Hall Problems

montyhall.py

import random
from enum import Enum, auto, unique

@unique
class Prize(Enum):
    CAR = auto()
    GOAT = auto()

results = {
    Prize.CAR: 0,
    Prize.GOAT: 0,
}

doors = [Prize.CAR, Prize.GOAT, Prize.GOAT]

for _ in range(1_000_000):
    random.shuffle(doors)
    unselected_doors = [0, 1, 2]

    # Player selects a random door.
    player_choice = random.choice(unselected_doors)
    unselected_doors.remove(player_choice)

    # Monty intentionally choosese a goat door to show the player.
    monty_hall_choice = next(i for i in unselected_doors if doors[i] is Prize.GOAT)
    unselected_doors.remove(monty_hall_choice)

    # Switch to the only remaining door
    switch_choice = unselected_doors[0]

    results[doors[switch_choice]] += 1

car = results[Prize.CAR]
goat = results[Prize.GOAT]
total = car + goat
percent = car / total * 100

print(f'{percent:.2f}%')

montyhall_random.py

import random
from enum import Enum, auto, unique

@unique
class Prize(Enum):
    CAR = auto()
    GOAT = auto()

results = {
    Prize.CAR: 0,
    Prize.GOAT: 0,
}

doors = [Prize.CAR, Prize.GOAT, Prize.GOAT]

for _ in range(1_000_000):
    random.shuffle(doors)
    unselected_doors = [0, 1, 2]

    # Player selects a random door.
    player_choice = random.choice(unselected_doors)
    unselected_doors.remove(player_choice)

    # Monty selects one of the remaining doors randomly.
    monty_hall_choice = random.choice(unselected_doors)
    unselected_doors.remove(monty_hall_choice)

    # Skip scenarios where Monty didn't select a goat.
    if doors[monty_hall_choice] is Prize.CAR:
        continue

    # Switch to the only remaining door
    switch_choice = unselected_doors[0]

    results[doors[switch_choice]] += 1

car = results[Prize.CAR]
goat = results[Prize.GOAT]
total = car + goat
percent = car / total * 100

print(f'{percent:.2f}%')