sum_of_array.py

def _sum(arr)
    sum = 0
    for i in arr:
        sum = sum + i
 
    return(sum)

if __name__ == "__main__":
    
    arr = [12, 3, 4, 15]
    n = len(arr)
    ans = _sum(arr)
    print('Sum of the array is ', ans)
Output
Sum of the array is  34