The Ten Chests

ten-chests.py

import copy
import random

chests = [
    ['D', 'D', 'D'],
    ['D', 'D', 'E'],
    ['D', 'D', 'R'],
    ['D', 'E', 'E'],
    ['D', 'E', 'R'],
    ['D', 'R', 'R'],
    ['E', 'E', 'R'],
    ['E', 'R', 'R'],
    ['E', 'E', 'E'],
    ['R', 'R', 'R']
]

iterations = 100000
found_at_least_one_diamond = 0
found_two_diamonds = 0

for _ in range(iterations):
    # Not really necessary, but I abhor the idea of that jeweler's chests being disturbed!
    chest = copy.copy(random.choice(chests))
    random.shuffle(chest)

    if chest[0] == 'D':
        found_at_least_one_diamond += 1

        if chest[0:2] == ['D', 'D']:
            found_two_diamonds += 1

print(found_two_diamonds / found_at_least_one_diamond)