# Python Program To Find The Sum Of Elements Of An Array or List

## Problem Definition

Make a Python Function which takes an array or list as input and returns the sum of its elements, for example  array[ 1, 2, 3, 4] will return 1 + 2 + 3 + 4 = 10

## Solution

In this article, we will go through two different methods of tackling the same problem.

### Method 1: Using loop

In this method first, we are creating a variable `total` to store the sum and initializing it to 0. Next, the for loop iterates over each element of the array / list and storing their sum in the total variable, at last function returns the total.

``````def array_summer(arr):
total = 0
for item in arr:
# shorthand of total = total + item
total += item

#  Test input
print(array_summer([1, 2, 3, 3, 7]))
``````

Output:

``16``

## Method 2: Using Python’s built-in function sum() [ Recommended ]

Python comes with an in-built solution for adding items of iterable (list, tuple, dictionary), the `sum()` method simply returns the sum of each item of the gives list or array.

``````def array_summer(arr):
return sum(arr)

#  Test input
print(array_summer([1, 2, 3, 3, 7]))``````

Output:

``16``

we went through two different methods of summing the elements of an array however using `sum()` function made our code more compact and faster, for a very large list `sum()` is more efficient therefore it’s the recommended way.