Python Code
Samples
Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.
How to Check if a List is Sorted in Descending Order in Python
This code defines a function that returns True if a given list is sorted in descending order, using a generator expression with all() to compare each adjacent pair.
def is_descending(lst):
"""Return True if list is sorted in descending order."""
return all(lst[i] >= lst[i + 1] for i in range(len(lst) - 1))
if __name__ == "__main__":
test_cases = [
[5, 4, 3, 2, 1],
[3, 3, 2, 1],
[1, 2, 3],
[10, 8, 9],
[]
]
for case in …How to Sort a List in Python in Ascending and Descending Order
This code demonstrates three ways to sort a list in Python: returning a new sorted list with sorted(), reversing the sort order, and sorting a list in place with the list.sort() method.
def get_sorted_data(numbers):
"""Return a new list sorted in ascending order."""
return sorted(numbers)
def reverse_sort(data):
"""Return a new list sorted in descending order."""
return sorted(data, reverse=True)
def sort_in_place(data):
"""Sort the given list in place (modifies original)."""
…How to Sort a List of Dictionaries by a Key in Python
Sort a list of dictionaries by a specified key field, optionally in descending order, using Python's built-in sorted() function.
def sort_dicts_by_key(data, key, reverse=False):
return sorted(data, key=lambda item: item.get(key), reverse=reverse)
if __name__ == "__main__":
people = [
{"name": "Alice", "age": 30},
{"name": "Bob", "age": 25},
{"name": "Charlie", "age": 35},
]
sorted_by_age = sort_dicts_b…How to Sort a List of Dictionaries by Key with a Lambda in Python
Sort a list of dictionaries ascending or descending by one of their keys using sorted() with a lambda as the key function — a beginner-friendly pattern.
def get_students():
return [
{"name": "alice", "score": 85},
{"name": "bob", "score": 92},
{"name": "carol", "score": 78},
{"name": "dave", "score": 92},
]
students = get_students()
sorted_by_score = sorted(students, key=lambda s: s["score"])
print("Sorted by score (ascending)…How to Sort a List of Numbers in Python with Default Parameters
Define a reusable sort function that uses a default parameter to sort a list of numbers in ascending or descending order.
def sort_numbers(numbers, reverse=False):
"""Sort a list of numbers in ascending or descending order."""
return sorted(numbers, reverse=reverse)
def main():
numbers = [5, 2, 9, 1, 7, 3]
# Default sort (ascending)
ascending = sort_numbers(numbers)
print(f"Ascending: {ascending}")
…How to Sort a Python Dictionary by Value Descending
Sort dictionary items by their values in descending order and return a new dictionary.
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)Sort Unique Values by Frequency in Python
Count element frequencies with Counter and sort unique values by descending frequency, breaking ties alphabetically.
from collections import Counter
def sort_unique_by_frequency(values):
counts = Counter(values)
return sorted(counts.keys(), key=lambda x: (-counts[x], x))
if __name__ == "__main__":
data = [4, 2, 2, 8, 3, 3, 1, 3, 5, 5, 5, 5, 1]
result = sort_unique_by_frequency(data)
print(f"Sorted unique values…Sort list by multiple keys with tuple ordering in Python
Sort a list of dictionaries by multiple criteria — surname, age, then score descending — using a tuple key and negation.
def sort_multi_key(data):
# Sorts by surname, then age, then score descending
return sorted(
data,
key=lambda person: (
person['surname'].lower(),
person['age'],
-person['score'] # negative to reverse sort by score
)
)
if __name__ == "__main__"…How to Sort a List of Dictionaries by Key in Python
A reusable helper function that sorts a list of dictionaries by a specified key, with optional descending order support.
from typing import List
def sort_records(records: List[dict], key: str, descending: bool = False) -> List[dict]:
"""Sort a list of dictionaries by a specified key."""
return sorted(records, key=lambda record: record[key], reverse=descending)
def demonstrate_sorting() -> None:
users = [
{"name": …Browse by section
Each section groups closely related Python snippets.
Guide: free Python code samples library
Copy-ready Python snippets for learners and developers
PythonSkillset code samples are short, focused examples organised by topic and difficulty. Every snippet is server-rendered HTML — readable by search engines and easy to copy. Open any sample, read the notes, copy the code, then press Try in editor to run it in the browser with Pyodide.
How to use this library
- Pick a topic section — strings, lists, files, functions, and more
- Open a sample, read How it works, and copy the code block
- Run it in the IDE, tweak values, then take a related quiz or tutorial lesson
Samples vs tutorials and challenges
Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.