Python Sum List

Python List: Exercise-1 with Solution. Write a Python program to sum all the items in a list. Example - 1: Example - 2: Example - 3: Example - 4: Sample Solution:- Python Code: def sumlist(items): sumnumbers = 0 for x in items: sumnumbers += x return sumnumbers print(sumlist(1,2,-8)) Sample Output:-5 Flowchart: Visualize Python code. Write a Python Program to find Sum of Elements in a List with a practical example. Python Program to find Sum of Elements in a List This python program allows user to enter the length of a List. Next, we used Python For Loop to add numbers to the list.

  • Alculating the sum of a list is a common operation in Python. For example, let’s say you are a coffee shop owner who wants to know the total value of all sales made last month. You could use the sum function to perform this calculation. In Python code, the sum function can be used to calculate the sum of all values in an iterable object. This method is useful when you need the total value of a list of items, which is common in a number of mathematical calculations.
  • The Python sum function adds up all the numerical values in an iterable, such as a list, and returns the total of those values. Sum calculates the total of both floating-point numbers and integers. For instance, you could use the sum method to calculate the total price of the products a customer purchases at a store.
Python Sum List
  • Related Questions & Answers
  • Selected Reading
PythonServer Side ProgrammingProgramming

The cumulative sum till ith element refers to the total sum from 0th to ith element.

The program statement is to form a new list from a given list. The ith element in the new list will be the cumulative sum from 0 to ith element in the given list.

For example,





Following is a program to form a cumulative sum list using the input list −

  • The input list is passed to the function cumSum() which returns the cumulative sum list.

  • We declare an empty list cum_list to which we will append elements to form the cumulative sum list.

  • Initialize a sum variable sm=0.

  • Start iterating over the input list, with each iteration we increment the sum value to previous value+ the current element.

  • On each iteration, the sum value is appended to the cum_list.

  • Thus, on ith iteration, the sum variable will contain sum till the ith element(included), which is then appended to the cum_list.

  • Macbook rar unzip free. After iterating through the whole list, the cum_list is returned.




In Python, programmers work with a lot of lists. Sometimes, it is necessary to find out the sum of the elements of the lists for other operations within the program.

In this article, we will take a look at the following ways to calculate sum of all elements in a Python list:

1) Using sum() Method

Python provides an inbuilt function called sum() which sums up the numbers in a list.


  • Iterable – It can be a list, a tuple or a dictionary. Items of the iterable have to be numbers.
  • Start – This number is added to the resultant sum of items. The default value is 0.

The method adds the start and the iterable elements from left to right.


Code Example:



Here, you can see that the sum() method takes two parameters – numlist, the iterable and 5 as the start value. The final value is 61 (without the start value) and 66 (with the start value 5 added to it).

2) Using for Loop



Here, a for loop is run over the list callednumlist. With each iteration, the elements of the list are added. The result is 61 which is printed using the print statement.

3) Sum of List Containing String Value


Here, the list called numlistcontains integers as strings. Inside theforloop, these string elements are added together after converting them into integers, using the int() method.

4) Using While Loop


In this program, elements of the numlist array are added using a while loop. The loop runs until the variable i is less than the length of the numlistarray. The final summation is printed using the value assigned in thetotalsum variable.


Python Sum List Of Dictionary Values

Using a for loop or while loop is great for summing elements of a list. But the sum() method is faster when you are handling huge lists of elements.