monty_hall_en.py

import random

wins_not_changing_door = 0
wins_changing_door = 0

N = 1000000 #we run a bunch of experiments
for i in range(N):
    doors = [0,0,0] #0 denotes a goat, 1 denotes a prize
    prize = random.randint(0,2)
    doors[prize] = 1
    guess = random.randint(0,2) #first choose - random
    positions_left = [i for i in range(3) if i != guess and i != prize] #these are the choise variants to not show the prize
    shown = random.sample(positions_left,1)[0] #showrunner picks one position
    position_for_change = random.sample([i for i in range(3) if i != guess and i != shown], 1)[0]#and we pick a position for a change
    if doors[guess] == 1:
        wins_not_changing_door += 1 #we would win if we would NOT change the door
    if doors[position_for_change] == 1:
        wins_changing_door += 1 #we would win if we would change the door
#and the final result:
print('Wins when not changing door:', wins_not_changing_door, '(', 100 * wins_not_changing_door/ N, "%)")    
print('Wins when changing door:', wins_changing_door, '(', 100 * wins_changing_door/ N, "%)") 

#-----------------Output example:----------------
#Wins when not changing door: 333512 ( 33.3512 %)
#Wins when changing door: 666488 ( 66.6488 %)
#------------------------------------------------