numbers = range(-10, 11) numbers = list(numbers) numbers.remove(0) mysum = numbers[0] + numbers[1] + numbers[2] + numbers[3] + numbers[4] + numbers[5] + numbers[6] + numbers[7] + numbers[8] + numbers[9] + numbers[10] + numbers[11] + numbers[12] + numbers[13] + numbers[14] + numbers[15] + numbers[16] + numbers[17] + numbers[18] + numbers[19] myproduct = numbers[0] * numbers[1] * numbers[2] * numbers[3] * numbers[4] * numbers[5] * numbers[6] * numbers[7] * numbers[8] * numbers[9] * numbers[10] * numbers[11] * numbers[12] * numbers[13] * numbers[14] * numbers[15] * numbers[16] * numbers[17] * numbers[18] * numbers[19] print(mysum, myproduct) from functools import reduce assert mysum == sum(numbers) assert myproduct == reduce(lambda x,y: x*y, numbers)