Python: Compute cumulative sum of numbers of a given list

Last update on April 17 2025 13:01:09 (UTC/GMT +8 hours)

Cumulative Sum of List

Write a Python program to compute the cumulative sum of numbers in a given list.
Note: Cumulative sum = sum of itself + all previous numbers in the said list.

Sample Solution:

Python Code:

# Define a function named nums_cumulative_sum that takes a list of numbers (nums_list) as an argument.
def nums_cumulative_sum(nums_list):
    # Use a list comprehension to calculate the cumulative sum for each element in the input list.
    # The sum(nums_list[:i+1]) calculates the sum of elements up to the current index i.
    # The loop iterates over each index i in the range of the length of the input list.
    return [sum(nums_list[:i+1]) for i in range(len(nums_list))]

# Test the function with different lists of numbers and print the results.

# Test case 1
print(nums_cumulative_sum([10, 20, 30, 40, 50, 60, 7]))

# Test case 2
print(nums_cumulative_sum([1, 2, 3, 4, 5]))

# Test case 3
print(nums_cumulative_sum([0, 1, 2, 3, 4, 5]))

Sample Output:

[10, 30, 60, 100, 150, 210, 217]
[1, 3, 6, 10, 15]
[0, 1, 3, 6, 10, 15]

Explanation:

Here is a breakdown of the above Python code:

Function definition:

The code defines a function named "nums_cumulative_sum()" that takes a list of numbers (nums_list) as an argument.

List comprehension:

The function uses list comprehension to generate a new list where each element is the cumulative sum of the elements up to the current index.

Summation Expression:

The expression sum(nums_list[:i+1]) calculates the sum of elements from index 0 to the current index i.

Loop Over Indices:

The loop iterates over each index i in the range of the length of the input list (range(len(nums_list))).

Visual Presentation:

Python: Compute cumulative sum of numbers of a given list.

Flowchart:

For more Practice: Solve these Related Problems:

Write a Python program to compute the cumulative sum of a list of integers and return a new list with the running totals.
Write a Python program to generate a list where each element is the sum of itself and all previous numbers.
Write a Python program to calculate running totals for a given list using itertools.accumulate.
Write a Python program to compute the cumulative sum of an array without using built-in accumulation functions.

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Python Code Editor:

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