Python Program to print sum of all key value pairs in a Dictionary

Given a dictionary arr consisting of N items, where key and value are both of integer type, the task is to find the sum of all key value pairs in the dictionary.

Examples:

Input: arr = {1: 10, 2: 20, 3: 30}
Output: 11 22 33
Explanation:
Sum of key and value of the first item in the dictionary = 1 + 10 = 11.
Sum of key and value of the second item in the dictionary = 2 + 20 = 22.
Sum of key and value of the third item in the dictionary = 3 + 30 = 33.

Input: arr = {10 : -5, 5 : -10, 100 : -50}
Output: 5 -5 50

Method 1:

Approach using dictionary traversal technique: The idea is to traverse through the keys of dictionary using for loop. Follow the steps below to solve the problem:

• Initialize a list, say l, to store the result.
• Traverse the dictionary arr and then append i + arr[i] into the list l.
• After completing the above steps, print the list l as the required answer.

Below is the implementation of the above approach:

Python3

# Python3 implementation of
# the above approach

# Function to print the list containing
# the sum of key and value pairs of
# each item of a dictionary


def FindSum(arr):

    # Stores the list containing the
    # sum of keys and values of each item
    l = []

    # Traverse the dictionary
    for i in arr:

        l.append(i + arr[i])

    # Print the list l
    print(*l)

# Driver Code


arr = {1: 10, 2: 20, 3: 30}

FindSum(arr)

Output

11 22 33

Time Complexity: O(N)
Auxiliary Space: O(N)

Method 2:

Approach using keys() Method: An alternate approach to solve the problem is to use keys() method. Follow the steps below to solve the problem:

• Initialize a list, say l, to store the result.
• Traverse through the list of keys of dictionary arr and then append.
• After completing the above steps print the list l as answer.

Below is the implementation of the above approach:

Python3

# Python3 implementation of the above approach

# Function to print the list
# containing the sum of key and
# value pairs from a dictionary


def FindSum(arr):

    # Stores the list containing the
    # sum of keys and values of each item
    l = []

    # Traverse the list of keys of arr
    for i in arr.keys():

        l.append(i + arr[i])

    # Print the list l
    print(*l)

# Driver Code


arr = {1: 10, 2: 20, 3: 30}

FindSum(arr)

Output

11 22 33

Time Complexity: O(N)
Auxiliary Space: O(N)

Method 3 : Using keys(),values() and for loop

Python3

# Python3 implementation of the above approach
arr = {1: 10, 2: 20, 3: 30}
x = list(arr.keys())
y = list(arr.values())
res = []
for i in range(0, len(x)):
    res.append(x[i]+y[i])
for i in res:
    print(i, end=" ")

Output

11 22 33 

Method 4: Using zip() and a list comprehension

This approach uses the python built-in function zip() to extract the keys and values of the dictionary and combines them in a tuple. Using a list comprehension, we add the key and value of each item in the dictionary. The final result is the sum of all key-value pairs in the dictionary. The time complexity of this approach is O(n) and the space complexity is O(n) as we are creating a new list to store the sum of each key-value pair.

Python3

def find_sum(arr):
    # Using zip to get the keys and values of the dictionary
    keys, values = zip(*arr.items())
    # Using list comprehension to add the key and value of each item
    return [k+v for k,v in zip(keys, values)]

arr = {1: 10, 2: 20, 3: 30}
print(find_sum(arr))
#This code is contributed by Edula Vinay Kumar Reddy

Output

[11, 22, 33]