Question

(I mean the Monty Hall problem, this site won’t let me submit something with ‘problem’ in the title)

I’m attempting to create the Monty Hall problem in python, I thought I had a good plan, but I’m getting the error ‘”NoneType’ object is not subscriptable”. This happens when I try to nest the lists. Does anyone know how I can do this? or fix it?

Thank you.

Here is the code:

car = 0
goat = 0
turns = 0
amount = 100

import random

items = ["New Car", "Goat", "Goat"]
doors = ["Door1", "Door2", "Door3"]

while turns < amount:
    x = random.shuffle(items)
    door = random.shuffle(doors)
    door1 = [door[0], x[0]]
    door2 = [door[1], x[1]]
    door3 = [door[2], x[2]]

    new_list = [door1, door2, door3]

    player_choice = random.randint(0, 2)
    if player_choice == 0:
        print("You have chosen {0}, and behind that is a {1}".format(door1[0], door1[1]))
        if new_list[0][1] == "New Car":
            car += 1
            turns += 1
        else:
            goat += 1
            turns += 1

And then error:

Traceback (most recent call last):
  File "<string>", line 250, in run_nodebug
  File "C:\Programming\Random Programs\Monty Hall Problem.py", line 16, in <module>
    door1 = [door[0], x[0]]
TypeError: 'NoneType' object is not subscriptable

Answer 1

random.shuffle doesn’t return a result. It just modifies the list you pass as an argument.

Perhaps you want something like this?

random.shuffle(items)
random.shuffle(doors)
door1 = [doors[0], items[0]]
door2 = [doors[1], items[1]]
door3 = [doors[2], items[2]]