Python Program to Sort a Dictionary by Value

Introduction

Sorting a dictionary by its values is a common task when you need to organize data based on the magnitude of the values rather than the keys. This tutorial will guide you through creating a Python program that sorts a dictionary by its values.

Example:

Input Dictionary: {'b': 3, 'a': 1, 'c': 2}
Output Dictionary (sorted by value): {'a': 1, 'c': 2, 'b': 3}
Input Dictionary: {'banana': 3, 'apple': 1, 'cherry': 2}
Output Dictionary (sorted by value): {'apple': 1, 'cherry': 2, 'banana': 3}

Problem Statement

Create a Python program that:

Takes a dictionary as input.
Sorts the dictionary by its values.
Displays the sorted dictionary.

Solution Steps

Create a Dictionary: Initialize a dictionary with some key-value pairs.
Sort the Dictionary by Values: Use the sorted() function with a custom key to sort the dictionary by values.
Display the Sorted Dictionary: Use the print() function to display the sorted dictionary.

Python Program

# Python Program to Sort a Dictionary by Value
# Author: https://www.rameshfadatare.com/

# Step 1: Create a dictionary with key-value pairs
my_dict = {
    'b': 3,
    'a': 1,
    'c': 2,
    'd': 4
}

# Step 2: Sort the dictionary by values using the sorted() function and lambda
sorted_dict = dict(sorted(my_dict.items(), key=lambda item: item[1]))

# Step 3: Display the sorted dictionary
print("The sorted dictionary by value is:", sorted_dict)

Explanation

Step 1: Create a Dictionary with Key-Value Pairs

A dictionary my_dict is created with some key-value pairs, such as 'b': 3, 'a': 1, 'c': 2, and 'd': 4.

Step 2: Sort the Dictionary by Values Using the sorted() Function and lambda

The sorted() function is used to sort the items of the dictionary by values. The key=lambda item: item[1] argument tells the sorted() function to sort the dictionary based on the second element of the tuple (i.e., the value). The sorted list of tuples is then converted back into a dictionary using the dict() constructor.

Step 3: Display the Sorted Dictionary

The print() function is used to display the sorted dictionary.

Output Example

Example 1:

The sorted dictionary by value is: {'a': 1, 'c': 2, 'b': 3, 'd': 4}

Example 2:

# Python Program to Sort a Dictionary by Value
# Author: https://www.rameshfadatare.com/

# Step 1: Create a dictionary with key-value pairs
my_dict = {
    'banana': 3,
    'apple': 1,
    'cherry': 2,
    'date': 4
}

# Step 2: Sort the dictionary by values using the sorted() function and lambda
sorted_dict = dict(sorted(my_dict.items(), key=lambda item: item[1]))

# Step 3: Display the sorted dictionary
print("The sorted dictionary by value is:", sorted_dict)

Output:

The sorted dictionary by value is: {'apple': 1, 'cherry': 2, 'banana': 3, 'date': 4}

Example 3:

# Python Program to Sort a Dictionary by Value
# Author: https://www.rameshfadatare.com/

# Step 1: Create a dictionary with key-value pairs
my_dict = {
    'zebra': 50,
    'ant': 10,
    'elephant': 70,
    'cat': 30
}

# Step 2: Sort the dictionary by values using the sorted() function and lambda
sorted_dict = dict(sorted(my_dict.items(), key=lambda item: item[1]))

# Step 3: Display the sorted dictionary
print("The sorted dictionary by value is:", sorted_dict)