How to sort a dictionary in Python?

A dictionary is a data structure that consists of key and value pairs. We can sort a dictionary using two criteria −

Sort by key − The dictionary is sorted in ascending order of its keys. The values are not taken care of.

Sort by value − The dictionary is sorted in ascending order of the values.

Sort Dictionary by Key

In this approach, the dictionary is sorted in ascending order of its keys.

Input:

{2:90, 1: 100, 8: 3, 5: 67, 3: 5}

Output:

{1:100, 2:90, 3:5, 5:67, 8:3}

As shown above, we can see the dictionary is sorted according to its keys.

Using Loop with sorted()

dic = {2:90, 1: 100, 8: 3, 5: 67, 3: 5}
dic2 = {}
for i in sorted(dic):
    dic2[i] = dic[i]
print(dic2)

{1: 100, 2: 90, 3: 5, 5: 67, 8: 3}

Using Dict Comprehension

A more concise approach using dictionary comprehension ?

dic = {2:90, 1: 100, 8: 3, 5: 67, 3: 5}
sorted_dict = {key: dic[key] for key in sorted(dic)}
print(sorted_dict)

{1: 100, 2: 90, 3: 5, 5: 67, 8: 3}

How It Works

• sorted(dic) returns all the keys of the dictionary in sorted order as a list: [1, 2, 3, 5, 8]
• For each key in sorted order, we add the key and corresponding value to the new dictionary
• The result is a dictionary with all key-value pairs in sorted order of keys

Sort Dictionary by Values

In this approach, the dictionary is sorted in ascending order of values.

Input:

{2:90, 1: 100, 8: 3, 5: 67, 3: 5}

Output:

{8:3, 3:5, 5:67, 2:90, 1:100}

As shown above, we can see the dictionary is sorted according to its values.

Using sorted() with items()

dic = {2:90, 1: 100, 8: 3, 5: 67, 3: 5}
dic2 = dict(sorted(dic.items(), key=lambda x: x[1]))
print(dic2)

{8: 3, 3: 5, 5: 67, 2: 90, 1: 100}

How It Works

• The items() method returns key-value pairs as tuples: [(2, 90), (1, 100), ...]
• The key=lambda x: x[1] tells sorted() to sort by the second element (value) of each tuple
• dict() converts the sorted list of tuples back into a dictionary

Comparison

Conclusion

Use dictionary comprehension with sorted() for sorting by keys. Use sorted() with items() and a lambda function for sorting by values. Both approaches create a new sorted dictionary.