Reference library

Lists & loops

Iterate, transform, and combine sequences with readable loop patterns.

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Lists & loops easy

How to Calculate a Cumulative Sum in Python

Build a new list where each element equals the running total of all numbers up to that index in the original list.

lists cumulative-sum loops
Python 
numbers = [1, 2, 3, 4, 5]
cumulative_sum = []
running_total = 0

for num in numbers:
    running_total += num
    cumulative_sum.append(running_total)

print(cumulative_sum)
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Lists & loops — Python code examples

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