monteurn.py

import random

def initialize_urn():  
    reds = ["red" for i in range(50)]
    blacks = ["black" for i in range(50)]
    return reds + blacks

def get_pair(urn):
    choice_1 = random.choice(urn)
    urn.remove(choice_1)
    choice_2 = random.choice(urn)
    urn.remove(choice_2)
    return [choice_1, choice_2]

def approximate():
    num_trials = 10000
    num_draws = 50
    trial_results = []
    for trial in range(num_trials):
        num_both = 0
        urn = initialize_urn()
        for draw in range(num_draws):
            pair = get_pair(urn)
            if "red" in pair and "black" in pair:
                num_both += 1
        trial_results.append(float(num_both))
    average_both = sum(trial_results) / num_trials
    print average_both