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name: python description: Use for Python work with uv—envs, deps, and commands run through uv; avoid pip/venv/pip-tools; keep Justfile/CI parity with ruff, mypy, pytest.

Python (uv-only)

Overview

Standardize Python workflows on uv for envs, dependency resolution, and execution. No pip, venv, or pip-tools unless forced by third-party tooling.

When to Use

• Any Python install/run/test/lint/typecheck in this repo.
• Setting up new projects or maintaining existing ones.
• CI steps for Python.

Core Pattern

• Standard commands (keep CI aligned): uv venv .venv && source .venv/bin/activate && uv sync; uv run ruff format --check .; uv run ruff check .; uv run mypy .; uv run pytest; uv lock; combine as needed for CI.
• Env: uv venv .venv; activate shell or direnv; never use system/site-packages.
• Deps: uv add <pkg>; dev deps uv add --dev ruff mypy pytest; sync uv sync; commit uv.lock + pyproject.toml.
• Run: always uv run <cmd> (python, pytest, scripts).
• CI: uv sync --frozen; uv run pytest (plus ruff/mypy as needed).

Quick Reference

Red Flags

• Any pip install, python -m venv, or pipenv/poetry use.
• Missing uv.lock in repo.
• Running python script.py without uv run.
• Mixing global site-packages with project env.

Verification

• Fresh clone: uv venv && uv sync --frozen && uv run pytest succeeds without pip.
• which pip points to .venv/bin/pip created by uv.