Python - Tooling & Dev Experience

Overview

Estimated time: 30–45 minutes

Set up a productive Python workflow: editors, formatters, linters, tests, and environment management.

Learning Objectives

• Use black and ruff for fast, consistent formatting and linting.
• Run tests quickly with pytest and manage environments with venv/pyenv/pipx.
• Integrate tooling via pre-commit hooks and editor extensions.

Prerequisites

• Python - Standard Library Highlights

Format & Lint

pip install black ruff
black .
ruff .

Tests

pip install pytest
pytest -q

pre-commit

pip install pre-commit
pre-commit sample-config > .pre-commit-config.yaml
pre-commit install

Environment basics

python -m venv .venv
source .venv/bin/activate  # Windows: .venv\\Scripts\\activate
pip install -U pip

Common Pitfalls

• Global installs causing version conflicts—use virtual environments.
• Running tools inconsistently—automate with pre-commit and CI.

Checks for Understanding

1. Why run formatters/linters locally and in CI?
2. What’s the benefit of pre-commit over manual tool runs?

Exercises

1. Add black and ruff to a project and configure them in .pre-commit-config.yaml.
2. Set up a fresh venv and run pytest; add one failing and one passing test.