Python Quality Tooling

Overview

Use ruff, ty, and pytest consistently through uv. Core principle: one repeatable quality gate across local and CI.

Quick Reference

Task Command

Lint uv run ruff check

Auto-fix uv run ruff check --fix

Format uv run ruff format

Type check uv run ty check

Test uv run pytest

Coverage uv run pytest --cov=src --cov-report=term-missing

Full gate (prek) prek run -a

Install git hooks (prek) prek install

Workflow

• Install tools as dev deps (see python-uv-project-setup ).

• Run all checks before commit.

• Keep CI aligned with local commands.

• If the repo uses prek, prefer prek run -a as the single quality gate.

• Pytest tests MUST be function-based (no class-based tests or unittest.TestCase ).

Example

Pre-merge gate:

uv run ruff check --fix uv run ruff format uv run ty check uv run pytest --cov=src --cov-report=term-missing

Common Mistakes

• Running tools outside uv (drifts from project env).

• Skipping prek run -a when a repo standardizes on prek.

• Running only one tool and calling it done.

Red Flags

• Direct ruff /pytest invocations without uv run .

• Mixing pre-commit and prek commands in the same repo.

• Class-based pytest tests (class Test* ) or unittest.TestCase usage.

References

• references/quality.md

• Full command set and CI example

• references/quality.md

• Prek install and usage notes (prefer uv tool install prek )