Python: Cumulative Sum of List - How to Guide

If you're working with Python and need to calculate the cumulative sum of a list, you've come to the right place. In this guide, we'll walk you through the steps to calculate the cumulative sum of a list using Python.

What is a Cumulative Sum?

A cumulative sum is the sum of a sequence of numbers up to a certain point in the sequence. For example, the cumulative sum of the sequence 1, 2, 3, 4 is 1, 3, 6, 10.

Calculating the Cumulative Sum of a List in Python

To calculate the cumulative sum of a list in Python, we can use a for loop to iterate over the list and add each value to a running total. Here's an example:

<!-- language: python -->
# Define a list of numbers
numbers = [1, 2, 3, 4]

# Define a variable to store the running total
total = 0

# Define an empty list to store the cumulative sum
cumulative_sum = []

# Iterate over the list of numbers
for num in numbers:
    # Add the current number to the running total
    total += num
    # Append the running total to the cumulative sum list
    cumulative_sum.append(total)

# Print the cumulative sum
print(cumulative_sum)

In this example, we define a list of numbers and initialize variables to store the running total and cumulative sum. We then iterate over the list of numbers, adding each value to the running total and appending the running total to the cumulative sum list. Finally, we print the cumulative sum.

When we run this code, we get the following output:

[1, 3, 6, 10]

As you can see, the cumulative sum of the list [1, 2, 3, 4] is [1, 3, 6, 10].

Conclusion

Calculating the cumulative sum of a list in Python is a simple task that can be accomplished using a for loop. By following the steps outlined in this guide, you should now be able to calculate the cumulative sum of any list in Python.