Sort a Dictionary Without Using Sort Function in Python

As we all know Dictionaries in Python are unordered by default, which means they can’t be sorted directly. However, we can sort the keys or values of a dictionary and create a new sorted dictionary from the sorted keys or values. We can sort a list in a Dictionary using the inbuilt dictionary sort() function. But in this article, we will learn how we can sort a Dictionary in a particular order without using the list sort() method.

Sorting a Dictionary Without Using Sort Function in Python

Below, are the methods of How to Sort a Dictionary in Python Without a Sort Function in Python:

1. Using min() Function
2. Using the For loop
3. Using heapq Module
4. Using Recursion

Sort a Dictionary in Python Using min Function

In this approach, we repeatedly find and remove the key with the minimum value from the original dictionary, creating a sorted dictionary based on the values.

Python3

def sort_dict_min(original_dict):
    sorted_dict = {}
    while original_dict:
        min_key = min(original_dict, key=original_dict.get)
        sorted_dict[min_key] = original_dict.pop(min_key)
    return sorted_dict

# Example Usage
original_dict = {'banana': 3, 'apple': 1, 'orange': 2}
print("Original Dictionary:", original_dict)

sorted_dict = sort_dict_min(original_dict)
print("Sorted Dictionary :", sorted_dict)

Output

Original Dictionary: {'banana': 3, 'apple': 1, 'orange': 2}
Sorted Dictionary : {'apple': 1, 'orange': 2, 'banana': 3}

Sort a Dictionary in Python Using Loop and sorted Function

In this approach, we use a loop and the sorted() function to iterate through the keys of the original dictionary in sorted order based on their values, creating a sorted dictionary.

Python3

def sort_dict_using_loop(original_dict):
    sorted_dict = {}
    for key in sorted(original_dict, key=original_dict.get):
        sorted_dict[key] = original_dict[key]
    return sorted_dict


# Example Usage
original_dict = {'banana': 3, 'apple': 1, 'orange': 2}
print("Original Dictionary:", original_dict)

sorted_dict = sort_dict_using_loop(original_dict)
print("Sorted Dictionary ", sorted_dict)

Output

Original Dictionary: {'banana': 3, 'apple': 1, 'orange': 2}
Sorted Dictionary  {'apple': 1, 'orange': 2, 'banana': 3}

Sort a Dictionary in Python Using heapq Module

In this approach, we use the heapq module, this method finds the smallest items based on values, creating a sorted dictionary from the result.

Python3

import heapq

def sort_dict_heapq(original_dict):
    sorted_items = heapq.nsmallest(len(original_dict),
                                   original_dict.items(), key=lambda x: x[1])

    sorted_dict = dict(sorted_items)
    return sorted_dict

# Example Usage
original_dict = {'banana': 3, 'apple': 1, 'orange': 2}
print("Original Dictionary:", original_dict)

sorted_dict = sort_dict_heapq(original_dict)
print("Sorted Dictionary:", sorted_dict)

Output

Original Dictionary: {'banana': 3, 'apple': 1, 'orange': 2}
Sorted Dictionary: {'apple': 1, 'orange': 2, 'banana': 3}

Sort a Dictionary in Python Using Recursion

In this approach, we find and remove the key with the minimum value, creating a sorted dictionary by repeatedly updating it until the original dictionary is empty.

Python3

def sort_dict_recursive(original_dict):
    if not original_dict:
        return {}
    min_key = min(original_dict, key=original_dict.get)
    sorted_dict = {min_key: original_dict.pop(min_key)}
    sorted_dict.update(sort_dict_recursive(original_dict))
    return sorted_dict

# Example Usage
original_dict = {'banana': 3, 'apple': 1, 'orange': 2}
print("Original Dictionary:", original_dict)

sorted_dict = sort_dict_recursive(original_dict)
print("Sorted Dictionary :", sorted_dict)

Output

Original Dictionary: {'banana': 3, 'apple': 1, 'orange': 2}
Sorted Dictionary : {'apple': 1, 'orange': 2, 'banana': 3}

Conclusion

In this article, we studied on how to sort a dictionary in Python without using the built-in sorted function. From this article we understood it can be achieved through various approaches. The presented methods showcase different techniques, including using the min function, custom sorting functions, the heapq module, recursion, and a loop with the sorted function. Each method provides a unique way to create a sorted dictionary based on the values of the original dictionary.