python-env_skill

Overview

This skill provides fast Python environment management using uv, delivering 10-100x faster package operations than pip. It streamlines creating virtual environments, installing packages, running scripts, and managing dependencies from pyproject configurations. The workflow is focused on speed, reproducibility, and common developer tasks for local projects.

How this skill works

The skill wraps common environment tasks as uv commands: uv venv to create virtual environments, uv pip ... to install/uninstall/list packages, and uv run to execute scripts inside the project context. It can target specific Python versions, handle requirements or pyproject dependencies, and includes helpers for resolving conflicts and cleaning caches.

When to use it

• Setting up a new project and creating an isolated virtual environment quickly
• Installing, upgrading, or removing packages with much faster install times
• Running scripts inside the project environment without manual activation (uv run)
• Bootstrapping a development environment from pyproject.toml or requirements.txt
• Troubleshooting dependency conflicts or cleaning cached artifacts

Best practices

• Create a venv per project with uv venv (or uv venv --python X.Y for a specific interpreter)
• Declare dependencies in pyproject.toml for reproducible installs and use optional-dependencies for dev tooling
• Use uv pip install -r requirements.txt for pinned builds, and uv pip install -e '.[dev]' during setup
• Use uv pip compile --resolver=backtracking when facing conflicting dependency constraints
• Prefer uv run to execute scripts in the environment instead of manual activate/deactivate steps

Example use cases

• Bootstrap a new app: mkdir my-project && cd my-project; uv venv; create pyproject.toml; uv pip install -e '.[dev]'
• Quickly install runtime and dev dependencies: uv pip install fastapi 'uvicorn[standard]' pytest ruff
• Run tests inside the project environment without activating: uv run pytest tests/
• Resolve a complex dependency conflict: uv pip compile --resolver=backtracking then uv pip install -r .venv/requirements.txt
• Recover from a missing interpreter: uv python install 3.11 and recreate the venv with uv venv --python 3.11