from random import randint def get_random(i, j): return randint(i, j) def shuffle(xs): for i in range(len(xs)): j = get_random(i, len(xs) - 1) xs[i], xs[j] = xs[j], xs[i] xs = list(range(1, 53)) print(xs) assert len(set(xs)) == 52 shuffle(xs) assert len(set(xs)) == 52 print(xs) print("Success!")