Sort Dictionary by Value Python Descending

Sometimes, we need to sort the dictionary by value in reverse order or descending order. We can perform this task easily by using Python. In this article, we will learn to Sort the Dictionary by Value in Descending Order using Python Programming. Below is an example to understand the problem statement.

Example:

Input: dict = {'Math': 90, 'DSA': 80, 'Algo': 95, 'Python': 75}
Output: {'Algo': 95, 'Math': 90, 'DSA': 80, 'Python': 75}

Sort Dictionary by Value Python in Descending Order

There are different methods to Sort Dictionary by Value in Descending Order using Python. Below we are explaining all the possible approaches with proper practical implementation.

1. Using the sorted() method and lambda Function
2. Using Counter and most_common() method
3. Using Dictionary Comprehension
4. Using heapq
5. Using itemgetter from the operator module
6. Using a combination of zip, sorted, and reversed

Sort Dictionary by Value in Reverse Order Using Lambda Function

In this approach, we use the sorted() method and Lambda function to sort the input_dict by values in the descending (high to low) order and store the result in the new dictionary as output with the descending order sorted key-value pairs.

Python3

# input dict
input_dict = {'Math': 90, 'DSA': 80, 'Algo': 95, 'Python': 75}

# sorting values in descending order
output = dict(sorted(input_dict.items(), key=lambda item: item[1], reverse=True))

# printing output
print(output)

Output

{'Algo': 95, 'Math': 90, 'DSA': 80, 'Python': 75}

Reverse Sort Dictionary by Value Using Counter and most_common() Method

In this approach, we are using the Counter class from the collections module to create the counter object from the input_dict, and the most_common() method sorts the dictionary by values in decending order and stores the output in the new dictionary as output.

Python3

from collections import Counter

# input dictionary
input_dict = {'Math': 90, 'DSA': 80, 'Algo': 95, 'Python': 75}

# sorting dictionary by values in descending order
output = dict(Counter(input_dict).most_common())

# Output
print(output)

Output

{'Algo': 95, 'Math': 90, 'DSA': 80, 'Python': 75}

Sort Dictionary by Value in Descending Order Using Dictionary Comprehension

In this example, the dictionary `my_dict` containing subject grades is sorted in descending order based on values using a dictionary comprehension with a lambda function as the sorting key, resulting in the `sorted_dict` displaying subjects and their corresponding scores.

Python3

my_dict = {'Math': 90, 'DSA': 80, 'Algo': 95, 'Python': 75}

sorted_dict = {key: value for key, value in sorted(
    my_dict.items(), key=lambda item: item[1], reverse=True)}

print(sorted_dict)

Output

{'Algo': 95, 'Math': 90, 'DSA': 80, 'Python': 75}

Python Reversibly Sort Dictionary by Value Using heapq Module

In this approach, we use the heapq module to Sort the dictionary in decending order. We are converting the input_dict into the list of tuples and then we are using the heapq to create the max heap based on the dictionary values and then we are getting the max elements to generate the new sorted dictionary as output.

Python3

import heapq

# input dictionary
input_dict = {'Math': 90, 'DSA': 80, 'Algo': 95, 'Python': 75}

# dictionaty to tuples
temp = list(input_dict.items())

# creating a max heap based on the values
heapq.heapify(temp)

output = dict(heapq.nlargest(len(temp), temp, key=lambda x: x[1]))

# prining output
print(output)

Output

{'Algo': 95, 'Math': 90, 'DSA': 80, 'Python': 75}

Reverse Sort Dictionary by Value Using itemgetter from the operator module

This approach utilizes the itemgetter(1) function from the operator module as key for sorting. Itemgetter(1) specifies that we are to sort based on the second element of each tuple (the values of the dictionary items). Reverse=True ensures that sorting is done in descending order.

Python3

from operator import itemgetter

my_dict = {'Math': 90, 'DSA': 80, 'Algo': 95, 'Python': 75}

sorted_dict = dict(sorted(my_dict.items(), key=itemgetter(1), reverse=True))
print(sorted_dict)

Output

{'Algo': 95, 'Math': 90, 'DSA': 80, 'Python': 75}

Python Reversibly Sort Dictionary by Value using a combination of zip, sorted, and reversed

We use sorted() to get a list of keys based on the values (key=my_dict.get) in descending order. Then, we use reversed() to reverse the order of the sorted values and finally zip and dict() to create tuples of key-value pairs and convert these tuples back into a dictionary.

Python3

my_dict = {'Math': 90, 'DSA': 80, 'Algo': 95, 'Python': 75}

sorted_items = dict(zip(sorted(my_dict, key=my_dict.get,
                               reverse=True), reversed(sorted(my_dict.values()))))
print(sorted_items)

Output

{'Algo': 95, 'Math': 90, 'DSA': 80, 'Python': 75}