Reference library

Python Code Samples

Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.

4 matches
Lists & loops easy

How to Truncate a List to Max Length in Python (Keep Head)

This code returns a new list containing only the first max_length items from the original list, using Python's slice syntax.

list slicing truncate
Python 
from typing import List

def truncate_head(lst: List[object], max_length: int) -> List[object]:
    """Return a new list with at most max_length items from the head."""
    if max_length < 0:
        raise ValueError("max_length must be non-negative")
    return lst[:max_length]

if __name__ == "__main__":
    # Examp…
14 0 Open
Functions & basics easy

Chain Generators with yield from in Python

Combine multiple generators into one seamless sequence using the `yield from` delegation syntax in Python.

generators yield delegation
Python 
def numbers():
    yield 1
    yield 2
    yield 3

def letters():
    yield 'a'
    yield 'b'
    yield 'c'

def combined():
    yield from numbers()
    yield from letters()

if __name__ == "__main__":
    print(list(combined()))
14 0 Open
Errors & debugging medium

How to Re-raise Exceptions with 'raise from' in Python

Shows how to re-raise an exception with explicit context chaining using the 'raise ... from ...' syntax, so the original cause is preserved for debugging.

exceptions raise-from error-handling
Python 
def divide_with_chain(a, b):
    try:
        result = a / b
        return result
    except ZeroDivisionError as original_error:
        # Re-raise with explicit chaining context
        raise ValueError("Cannot divide by zero") from original_error

def explain_chain():
    try:
        divide_with_chain(10, 0)
    …
11 0 Open
Comprehensions & generators easy

How to Use Comprehensions and Generators in Python

Demonstrate list, set, and dictionary comprehensions plus generator expressions and generator functions in one beginner-friendly script.

comprehensions generators yield
Python 
def demonstrate_comprehensions_generators():
    # List comprehension: transform and filter in one line
    numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
    squares = [num ** 2 for num in numbers if num % 2 == 0]
    print(f"Square of even numbers (list comprehension): {squares}")

    # Set comprehension: unique values
…
15 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.