Python program to find sum of elements in list

Given a list of numbers, write a Python program to find the sum of all the elements in the list.

Example:

Input: [12, 15, 3, 10]
Output: 40

Input: [17, 5, 3, 5]
Output: 30

Example #1:

Python3

# Python program to find sum of elements in list

total = 0

# creating a list
list1 = [11, 5, 17, 18, 23]

# Iterate each element in list
# and add them in variable total
for ele in range(0, len(list1)):
    total = total + list1[ele]

# printing total value
print("Sum of all elements in given list: ", total)

Output

Sum of all elements in given list:  74

Time Complexity: O(N), Here N is the number of elements in the list.
Auxiliary Space: O(1), As constant extra space is used.

Example #2 : Using while() loop  

Python3

# Python program to find sum of elements in list
total = 0
ele = 0

# creating a list
list1 = [11, 5, 17, 18, 23]

# Iterate each element in list
# and add them in variable total
while(ele < len(list1)):
    total = total + list1[ele]
    ele += 1

# printing total value
print("Sum of all elements in given list: ", total)

Output

Sum of all elements in given list:  74

Time Complexity: O(N), Here N is the number of elements in the list.
Auxiliary Space: O(1), As constant extra space is used.

Example #3: Recursive way  

Python3

# Python program to find sum of all
# elements in list using recursion

# creating a list
list1 = [11, 5, 17, 18, 23]

# creating sum_list function


def sumOfList(list, size):
    if (size == 0):
        return 0
    else:
        return list[size - 1] + sumOfList(list, size - 1)


# Driver code
total = sumOfList(list1, len(list1))

print("Sum of all elements in given list: ", total)

Output

Sum of all elements in given list:  74

Time Complexity: O(N), Here N is the number of elements in the list.
Auxiliary Space: O(1), As constant extra space is used.

Example #4: Using sum() method

Python3

# Python program to find sum of elements in list

# creating a list
list1 = [11, 5, 17, 18, 23]

# using sum() function
total = sum(list1)

# printing total value
print("Sum of all elements in given list: ", total)

Output

Sum of all elements in given list:  74

Time Complexity: O(N), Here N is the number of elements in the list.
Auxiliary Space: O(1), As constant extra space is used.

Example 5: Using add() function of operator module

First we have to import the operator module then using the add() function of operator module adding the all values in the list. 

Python3

# Python 3 program to find the sum of all elements in the
# list using add function of operator module

from operator import*
list1 = [12, 15, 3, 10]
result = 0
for i in list1:
  # Adding elements in the list using
  # add function of operator module
    result = add(i, result)
# printing the result
print(result)

Output

40

Time Complexity: O(N), Here N is the number of elements in the list.
Auxiliary Space: O(1), As constant extra space is used.

Method 6: Using enumerate function

Python3

list1 = [12, 15, 3, 10];s=0
for i,a in enumerate(list1):
  s+=a
print(s)

Output

40

Time Complexity: O(N), Here N is the number of elements in the list.
Auxiliary Space: O(1), As constant extra space is used.

Method 7: Using list comprehension 

Python3

list1 = [12, 15, 3, 10]
s=[i for i in list1]
print(sum(s))

Output

40

Time Complexity: O(N), Here N is the number of elements in the list.
Auxiliary Space: O(1), As constant extra space is used.

Method 8: Using lambda function

Python3

list1 = [12, 15, 3, 10]
print(sum(list(filter(lambda x: (x),list1))))

Output

40

Time Complexity: O(N), Here N is the number of elements in the list.
Auxiliary Space: O(1), As constant extra space is used.

Method: Using add operator 

Python3

import operator
list1 = [12, 15, 3, 10] ;s=0
for i in list1:
  s=s+operator.add(0,i)
print(s)

Output

40

Time Complexity: O(N), Here N is the number of elements in the list.
Auxiliary Space: O(1), As constant extra space is used.