Python Env

---
name: python-env
description: "Fast Python environment management with uv (10-100x faster than pip). Triggers on: uv, venv, pip, pyproject, python environment, install package, dependencies."
compatibility: "Requires uv CLI tool. Install: curl -LsSf https://astral.sh/uv/install.sh | sh"
allowed-tools: "Bash"
depends-on: []
related-skills: []
---

# Python Environment

Fast Python environment management with uv.

## Quick Commands

| Task | Command |
|------|---------|
| Create venv | `uv venv` |
| Install package | `uv pip install requests` |
| Install from requirements | `uv pip install -r requirements.txt` |
| Run script | `uv run python script.py` |
| Show installed | `uv pip list` |

## Virtual Environment

```bash
# Create venv (instant)
uv venv

# Create with specific Python
uv venv --python 3.11

# Activate (or use uv run)
source .venv/bin/activate  # Unix
.venv\Scripts\activate     # Windows
```

## Package Installation

```bash
# Single package
uv pip install requests

# Multiple packages
uv pip install flask sqlalchemy pytest

# With extras
uv pip install "fastapi[all]"

# Version constraints
uv pip install "django>=4.0,<5.0"

# Uninstall
uv pip uninstall requests
```

## Minimal pyproject.toml

```toml
[project]
name = "my-project"
version = "0.1.0"
requires-python = ">=3.10"
dependencies = [
    "httpx>=0.25",
    "pydantic>=2.0",
]

[project.optional-dependencies]
dev = [
    "pytest>=7.0",
    "ruff>=0.1",
]
```

## Project Setup Checklist

```bash
mkdir my-project && cd my-project
uv venv
# Create pyproject.toml
uv pip install -e ".[dev]"
uv pip list
```

## Troubleshooting

| Issue | Solution |
|-------|----------|
| "No Python found" | `uv python install 3.11` |
| Wrong Python version | `uv venv --python 3.11` |
| Conflicting deps | `uv pip compile --resolver=backtracking` |
| Cache issues | `uv cache clean` |

## When to Use

- **Always** use uv over pip for speed
- Creating virtual environments
- Installing packages
- Managing dependencies
- Running scripts in project context

## Additional Resources

For detailed patterns, load:
- `./references/pyproject-patterns.md` - Full pyproject.toml examples, tool configs
- `./references/dependency-management.md` - Lock files, workspaces, private packages
- `./references/publishing.md` - PyPI publishing, versioning, CI/CD

---

## See Also

This is a **foundation skill** with no prerequisites.

**Build on this skill:**
- `python-typing-patterns` - Type hints for projects
- `python-pytest-patterns` - Testing infrastructure
- `python-fastapi-patterns` - Web API development