Reference library

Dictionaries & sets

Key–value maps, uniqueness, counting, grouping, and fast lookups.

4 matches
Dictionaries & sets easy

How to Convert a Counter to a Plain Dict with Sorted Items in Python

This code converts a collections.Counter into a regular dictionary with items sorted by key, useful for stable, readable output.

counter dict sorting
Python
from collections import Counter

def counter_to_sorted_dict(counter):
    """Convert a Counter to a plain dict with sorted items."""
    return dict(sorted(counter.items()))

if __name__ == "__main__":
    # Example usage
    data = Counter(['apple', 'banana', 'apple', 'cherry', 'banana', 'date', 'apple'])
    print("…
13 0 Open
Dictionaries & sets easy

How to Sort Dictionary Keys Alphabetically in Python

This code returns a list of dictionary keys sorted alphabetically, using a case-insensitive comparison while preserving the original insertion order for keys that are equal.

sorting dictionary case-insensitive
Python
data = {
    "banana": 3,
    "apple": 1,
    "Cherry": 5,
    "date": 2,
    "apple": 4,
    "Fig": 6,
    "banana": 2,
}

def sort_dict_keys_alphabetically(d):
    """Return a list of keys sorted alphabetically (case-insensitive), stable for duplicates."""
    return sorted(d.keys(), key=lambda k: k.lower())

if __n…
11 0 Open
Dictionaries & sets easy

How to Sort a List of Dictionaries by Key in Python

Sort a list of dictionaries by various keys (grade, age, name) using lambda, itemgetter, and extract unique sorted names into a set.

sorting dictionaries sets
Python
from operator import itemgetter

# Sample data: a list of dictionaries representing students
students = [
    {"name": "Alice", "grade": 88, "age": 23},
    {"name": "Bob", "grade": 95, "age": 22},
    {"name": "Charlie", "grade": 78, "age": 24},
    {"name": "Diana", "grade": 92, "age": 21}
]

# Sort by grade (descen…
12 0 Open
Dictionaries & sets easy

How to Sort a Python Dictionary by Value Descending

Sort dictionary items by their values in descending order and return a new dictionary.

dictionary sorting values
Python
def sort_dict_by_value_desc(d):
    return dict(sorted(d.items(), key=lambda item: item[1], reverse=True))


if __name__ == "__main__":
    sample = {"apple": 5, "banana": 2, "cherry": 8, "date": 8}
    result = sort_dict_by_value_desc(sample)
    print(result)
12 0 Open

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