How to find the cumulative sum of numbers in a list?

Question

time_interval = [4, 6, 12]

I want to sum up the numbers like [4, 4+6, 4+6+12] in order to get the list t = [4, 10, 22].

Answer 1

In Python3, To find the cumulative sum of a list where the ith element is the sum of the first i+1 elements from the original list, you may do:

a = [4 , 6 , 12]
b = []
for i in range(0,len(a)):
    b.append(sum(a[:i+1]))
print(b)

OR you may use list comprehension:

b = [sum(a[:x+1]) for x in range(0,len(a))]

Output

[4,10,22]