CONTRIBUTING.md

Contributing to Python by Example

Thanks for helping improve this tutorial. The goal is to keep every example self-contained, runnable, and easy to learn from.

Requirements

• Python 3.10 or newer
• A virtual environment is recommended

python -m venv venv
# Windows
.\venv\Scripts\activate
# macOS / Linux
source venv/bin/activate

pip install -r requirements.txt

How to add or change an example

1. Keep one concept per file.
2. Follow the existing file header (topic, description, key concepts).
3. Include short comments that explain why, not only what.
4. Use modern type hints (list[str], dict[str, int], X | None).
5. Prefer the standard library unless a dependency is already listed in requirements.txt.

Tests

pytest

• Put tests in 11_testing/
• Name files test_*.py so pytest discovers them
• Cover both typical cases and edge cases

Code style

black .
isort .
mypy projects/04_weather_cli/solution.py

These tools are listed in requirements.txt. Match the style of nearby files if you are editing an existing lesson.

Pull requests

• Describe what you changed and why a learner benefits
• Keep unrelated refactors out of the same PR
• Make sure CI passes

Questions

Open an issue on GitHub if you are unsure where a new example belongs.