from itertools import accumulate a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] b = list(accumulate(a)) print(a) # [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] print(b) # [1, 3, 6, 10, 15, 21, 28, 36, 45, 55]