Reference library

Modern tooling

uv, ruff, pyproject.toml, packaging, and current Python project workflows.

49 matches
Modern tooling medium

How to set up mypy strict mode in Python

Demonstrates how to configure and run mypy in strict mode to enforce full type annotation coverage across a Python project.

mypy type-hints strict-mode
Python 
from typing import Dict, Optional


def describe_user(name: str, age: int, email: Optional[str] = None) -> Dict[str, object]:
    """Build a user description dictionary with strict type annotations."""
    user: Dict[str, object] = {"name": name, "age": age}
    if email is not None:
        user["email"] = email
    …
14 0 Open

Browse by section

Each section groups closely related Python snippets.

Modern tooling — Python code examples

What you will find here

This page collects modern tooling snippets — short, copy-ready Python you can paste into our free online IDE and run without installing anything. Each sample includes a plain-English explanation and the full source code.

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. Python code samples Copy-ready snippets to study and run in the IDE.