Regarding how to randomizing list with having equal probability

[deanhystad]

Problem with using combinations is the order is not random. After seeing as few as 3-4 sets, even if they are randomly selected, you'll begin to predict which image might come next.

from itertools import combinations

for combination in combinations((1, 2, 3, 4), 3):
    print(combination)

(1, 2, 3)
(1, 2, 4)
(1, 3, 4)
(2, 3, 4)