Uv: The Fast Python Package Manager

Python package management just got a massive upgrade. uv delivers 10-100x faster performance than pip while replacing your entire Python toolchain. Built in Rust by Astral (creators of Ruff), it’s rapidly becoming the new standard for Python development.

Why switch from pip to uv?

Speed that transforms your workflow:

• Package installation: 10-100x faster than pip
• Virtual environment creation: 80x faster than python -m venv
• Streamlit Cloud reduced deployment times by 55% after switching

One tool to rule them all:

• Replace pip, pip-tools, pipx, poetry, pyenv, and virtualenv
• Single binary with zero Python dependencies
• Consistent interface across all operations

Installation

# Linux/macOS (recommended) curl -LsSf https://astral.sh/uv/install.sh | sh # Using Homebrew brew install uv # Verify installation uv --version

Core commands you’ll use daily

Python version management

uv manages Python installations directly - no more pyenv or manual downloads:

# Install Python versions uv python install 3.12 uv python install 3.11.9 uv python install 3.10 # List available versions uv python list --all-versions # List installed versions uv python list # Pin project to specific version uv python pin 3.12 # Creates .python-version # Use specific Python version uv venv --python 3.11 uv run --python 3.12 python script.py

Starting a new project

# Create project with specific Python uv init my-project --python 3.12 cd my-project # uv automatically creates: # - pyproject.toml (modern Python standard) # - .python-version (pins Python version) # - .gitignore # - README.md # - main.py

Managing dependencies

# Add packages (auto-creates venv if needed) uv add requests fastapi # Add dev dependencies uv add --dev pytest black ruff # Update packages uv sync --upgrade # Remove packages uv remove unused-package

Running your code

No more manual virtual environment activation! uv handles everything:

# Run scripts uv run python main.py # Run tools uv run pytest uv run black . # Run without installing globally uvx ruff check . # Like npx for Python!

Quick migration guide: pip → uv

What you wantOld way (pip)New way (uv)

Install Python	pyenv install 3.12	uv python install 3.12
Create venv	python -m venv .venv	uv venv (or auto-created)
Create venv with specific Python	python3.11 -m venv .venv	uv venv --python 3.11
Install package	pip install requests	uv add requests
Install from requirements	pip install -r requirements.txt	uv pip install -r requirements.txt
Run script	source .venv/bin/activate && python main.py	uv run python main.py
Run with specific Python	python3.11 script.py	uv run --python 3.11 python script.py
Install global tool	pipx install black	uv tool install black

Practical example: FastAPI project

Let’s build a simple API to see uv in action:

# 1. Create project with Python 3.12 uv init weather-api --python 3.12 cd weather-api # 2. Add dependencies uv add fastapi uvicorn httpx # 3. Create main.py cat > main.py << 'EOF' from fastapi import FastAPI import httpx import sys app = FastAPI() @app.get("/") async def root(): return { "message": "Weather API with uv!", "python_version": sys.version } @app.get("/weather/{city}") async def get_weather(city: str): # Simulated weather data return { "city": city, "temperature": 22, "condition": "sunny", "powered_by": "uv" } if __name__ == "__main__": import uvicorn uvicorn.run(app, host="0.0.0.0", port=8000) EOF # 4. Run the API (uses Python 3.12 automatically) uv run python main.py # 5. Test with different Python version uv run --python 3.11 python main.py

That’s it! No virtual environment activation, no pip freeze, just fast and simple.

Best practices

Project structure

my-project/ ├── pyproject.toml # Single source of truth ├── .python-version # Python version for project ├── uv.lock # Commit this for reproducibility ├── src/ │ └── my_project/ └── tests/

Python version strategies

# For libraries - support multiple versions uv init my-lib --python ">=3.9" # For applications - pin specific version uv init my-app --python 3.12 uv python pin 3.12 # Test against multiple Python versions uv run --python 3.10 pytest uv run --python 3.11 pytest uv run --python 3.12 pytest

Dependency management

# Use constraints wisely uv add 'django>=4.0,<5.0' # For compatibility uv add 'numpy==1.24.3' # Pin critical deps # Organize by purpose uv add --dev pytest mypy # Dev tools uv add --group docs sphinx # Optional groups

CI/CD with GitHub Actions

name: Test on: [push] jobs: test: runs-on: ubuntu-latest strategy: matrix: python-version: ["3.10", "3.11", "3.12"] steps: - uses: actions/checkout@v4 - uses: astral-sh/setup-uv@v5 - run: uv python install ${{ matrix.python-version }} - run: uv sync --locked - run: uv run pytest

Common gotchas and solutions

Don’t activate virtual environments manually:

# ❌ Old habit source .venv/bin/activate python main.py # ✅ Let uv handle it uv run python main.py

Run from project root:

# ❌ Can cause import issues cd src && python ../scripts/test.py # ✅ Always from root uv run python scripts/test.py

Cache management:

# Check cache size uv cache info # Clean periodically uv cache clean

What’s new in 2024-2025

• Universal lockfiles for cross-platform reproducibility
• Python version management built-in (uv python install)
• 10-100x performance maintained across all operations
• 55,000+ GitHub stars and rapid adoption
• Official PyCharm support and growing ecosystem

Should you switch?

Yes, if you want:

• Dramatically faster dependency installation
• Simpler project management
• One tool instead of five
• Modern Python development experience

Start with:

• New projects (zero migration needed)
• CI/CD pipelines (massive time savings)
• Development environments (immediate productivity boost)

The Python ecosystem is rapidly adopting uv as the next-generation standard. Starting today means joining a growing community that’s already experiencing the future of Python package management.

Ready to go 10x faster? → curl -LsSf https://astral.sh/uv/install.sh | sh