def monty_choice(car, contestant): # this method simulates Monty opening an door behind which there is a goat # Parameters # car, which is either 1, 2 or 3, represents the door behind which is a car # contestant, which is either 1, 2 or 3, represents the door that contestant chooses # Returns # an integer, which is 1,2 or 3, represents the door that host chooses to open # write your code below this line

Here's one possible implementation of the `monty_choice` function in Python:

def monty_choice(car, contestant):
    # find the door that Monty can open
    options = [1, 2, 3]
    options.remove(car)
    if contestant in options:
        options.remove(contestant)
    door_to_open = random.choice(options)
    return door_to_open

This function takes in two parameters: `car` and `contestant`, which represent the door behind which is a car and the door that the contestant chooses, respectively. It returns an integer, which represents the door that Monty chooses to open.

The function first creates a list of all possible doors (`options`) and removes the door containing the car. If the contestant has not already chosen the car door, it also removes the contestant's chosen door. The function then randomly selects one of the remaining doors to open (`door_to_open`) and returns it.