How to sort a dictionary in Python by keys?

Python allows dictionaries to be sorted using the built-in sorted() function. Although dictionaries in Python 3.7+ preserve insertion order, we can still create a new dictionary sorted by its keys using various methods.

In this article, we will explore different ways to sort a dictionary in Python by its keys.

Using sorted() with Dictionary Comprehension

The most Pythonic way to sort a dictionary by keys is using dictionary comprehension with the sorted() function. This creates a new dictionary with keys in alphabetical order ?

data = {
    'zebra': 26,
    'apple': 1,
    'dog': 4,
    'cat': 3
}

# Sort dictionary by keys using comprehension
sorted_dict = {key: data[key] for key in sorted(data)}

print("Original:", data)
print("Sorted:  ", sorted_dict)

Original: {'zebra': 26, 'apple': 1, 'dog': 4, 'cat': 3}
Sorted:   {'apple': 1, 'cat': 3, 'dog': 4, 'zebra': 26}

Using sorted() with a Loop

You can also iterate through sorted keys to build a new dictionary manually ?

data = {
    'banana': 2,
    'apple': 1,
    'cherry': 3
}

# Create new dictionary by iterating sorted keys
sorted_dict = {}
for key in sorted(data.keys()):
    sorted_dict[key] = data[key]

print("Sorted dictionary:", sorted_dict)

Sorted dictionary: {'apple': 1, 'banana': 2, 'cherry': 3}

Sorting in Reverse Order

To sort keys in descending order, use the reverse=True parameter ?

scores = {'Alice': 85, 'Bob': 92, 'Charlie': 78, 'Diana': 96}

# Sort in reverse (descending) order
reverse_sorted = {key: scores[key] for key in sorted(scores, reverse=True)}

print("Reverse sorted:", reverse_sorted)

Reverse sorted: {'Diana': 96, 'Charlie': 78, 'Bob': 92, 'Alice': 85}

Using collections.OrderedDict

While regular dictionaries maintain order in Python 3.7+, you can use OrderedDict for explicit order management ?

from collections import OrderedDict

data = {'delta': 4, 'alpha': 1, 'gamma': 3, 'beta': 2}

# Sort using OrderedDict
sorted_ordered = OrderedDict(sorted(data.items()))

print("OrderedDict result:", sorted_ordered)
print("Type:", type(sorted_ordered))

OrderedDict result: OrderedDict([('alpha', 1), ('beta', 2), ('gamma', 3), ('delta', 4)])
Type: <class 'collections.OrderedDict'>

Comparison of Methods

Conclusion

Dictionary comprehension with sorted() is the most efficient and Pythonic way to sort dictionaries by keys. Use reverse=True for descending order, and consider OrderedDict when you need explicit order guarantees.