Reference library

Python Code Samples

Medium snippets you can copy, study, and run in the browser editor.

3 matches
Concurrency & performance medium

Benchmark list.append vs deque.append in Python

Measures and compares the performance of appending to a Python list versus a collections.deque using timeit.repeat, showing best and average timings.

benchmark performance list
Python 
"""Benchmark list.append vs collections.deque.append."""

import timeit

def bench(stmt, setup, repeat=5, number=1_000_000):
    times = timeit.repeat(stmt, setup=setup, repeat=repeat, number=number)
    return min(times), sum(times) / len(times)

if __name__ == "__main__":
    number = 1_000_000
    list_best, list_a…
12 0 Open
Concurrency & performance medium

How to Use ThreadPoolExecutor for Concurrent Tasks in Python

Compare sequential execution with ThreadPoolExecutor for I/O-bound tasks, measuring speedup and timing with perf_counter.

concurrency threadpool performance
Python 
import time
import threading
from concurrent.futures import ThreadPoolExecutor


def fetch_data(index):
    """Simulate a synchronous data fetch."""
    time.sleep(0.1)
    return f"data-{index}"


def run_sequential(total=10):
    """Run tasks one after another."""
    start = time.perf_counter()
    results = [fetch…
14 0 Open
System design patterns medium

How to Mock a Timeout per Dependency Call in Python

This code demonstrates how to simulate and test per-call timeouts for external dependencies using Python's unittest.mock and a simple timing wrapper.

mock timeout unittest
Python 
```python
import time
from unittest.mock import Mock, patch

def call_dependency(dependency, timeout):
    start = time.time()
    result = dependency.call()
    elapsed = time.time() - start
    if elapsed > timeout:
        raise TimeoutError(f"Dependency call took {elapsed:.2f}s, exceeding timeout {timeout}s")
    …
14 0 Open

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

  1. Pick a topic section — strings, lists, files, functions, and more
  2. Open a sample, read How it works, and copy the code block
  3. 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.

Related coding tools

Free online Python IDE Write and run Python in your browser — no install. Free Python code formatter Format with autopep8 — side-by-side PEP 8 cleanup.