Python env

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

# 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

# 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

[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

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

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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