Why Python developers should switch to uv

Introduction

Python development has long been plagued by slow package installations and complex dependency management. Enter uv, a new package manager developed by Astral (creators of Ruff) that’s transforming how Python developers handle projects.

What is uv?

uv is a super-fast Python package manager and project management tool that serves as a drop-in replacement for pip, but with dramatically enhanced capabilities.

At its core, uv addresses the fundamental pain points that have frustrated Python developers for years: slow installations, manual virtual environment management, and complex project setup processes.

Key benefits of uv

Speed and performance

The most striking feature of uv is its incredible speed. Where pip installations can take minutes, uv completes the same tasks in seconds:

• Up to 100x faster package installations compared to pip
• Near-instantaneous dependency resolution
• Dramatically reduced wait times for project setup

This speed improvement isn’t marginal. Tasks that previously interrupted your development flow now happen so quickly they become seamless.

Comprehensive project management

uv goes far beyond simple package installation. It provides a complete project management solution:

• Automatic project initialization with proper boilerplate structure
• Built-in virtual environment management with no manual activation required
• Intelligent dependency tracking that separates production and development packages
• Python version management without needing separate tools
• Automatic .gitignore generation with Python-specific excludes

Simplified dependency management

uv also changes the way you handle dependencies:

• Clean dependency lists: Only direct dependencies appear in pyproject.toml
• Easy package management: Simple uv add and uv remove commands
• Development dependencies: Separate development packages with --dev flag
• Automatic synchronization: Team members can instantly replicate environments

The new development workflow

uv transforms project setup from a multi-step manual process into a streamlined workflow:

Traditional workflow pain points

# The old way - multiple steps, slow process
mkdir new-project && cd new-project
python -m venv venv
source venv/bin/activate  # or venv\Scripts\activate on Windows
pip install package1 package2 package3
# Wait... and wait... for slow installations
pip freeze > requirements.txt

The uv way

# Initialize project with everything configured
uv init "new-ai-project"

cd "new-ai-project"

# Add dependencies instantly
uv add openai pydantic fastapi

# Add development tools separately
uv add ipykernel pytest --dev

# Run your code
uv run hello.py

This workflow reduces project setup time from minutes to approximately 15 seconds.

Essential uv commands

Project initialization

# Create new project with boilerplate
uv init "project-name"

This command automatically creates:

• Project directory structure
• .gitignore file with Python excludes
• pyproject.toml configuration
• Sample hello.py file
• README template
• Virtual environment

Dependency management

# Add production dependencies
uv add requests pandas numpy

# Add development dependencies  
uv add pytest black flake8 --dev

# Remove packages
uv remove pandas

# Sync environment from pyproject.toml
uv sync

Running code

# Execute Python files directly
uv run script.py

# Run with environment automatically activated
uv run python -m pytest

Comparison with traditional tools

uv vs pip

uv vs Poetry

While Poetry provides excellent dependency management, uv combines Poetry’s capabilities with superior speed and simpler workflows. uv’s faster installation and automatic environment handling make it more suitable for rapid development cycles.

uv vs Pipenv

uv surpasses Pipenv in both speed and reliability. Where Pipenv sometimes struggles with dependency resolution, uv handles complex dependencies effortlessly while maintaining its performance advantage.

Getting started with uv

Installation

Choose your preferred installation method:

macOS (recommended):

brew install uv

macOS/Linux (curl):

curl -LsSf https://astral.sh/uv/install.sh | sh

Windows: Follow the official installation guide at docs.astral.sh/uv

Verify installation:

uv --help

Migrating existing projects

uv maintains backward compatibility with existing Python projects:

From requirements.txt:

uv pip install -r requirements.txt

Convert to uv project:

uv init --existing-project
uv add $(cat requirements.txt | grep -v '^#' | tr '\n' ' ')

Advanced features

Python version management

uv can manage Python installations directly:

# List available Python versions
uv python list

# Install specific Python version
uv python install 3.12

# Use specific version for project
uv init --python 3.12 my-project

Team collaboration

uv makes team collaboration seamless:

1. Share project: Simply commit pyproject.toml to version control
2. Setup for teammates: uv sync creates identical environments instantly
3. No configuration drift: Locked dependencies ensure consistency

Integration with development tools

uv works seamlessly with modern development environments:

• IDEs: VS Code, PyCharm, Cursor automatically detect uv environments
• CI/CD: Simple integration with GitHub Actions, GitLab CI
• Docker: Excellent containerization support
• Version Control: Clean pyproject.toml files work perfectly with Git

Deploying Python applications with uv on Upsun

uv’s speed advantages make it perfect for cloud deployments. Here’s how to deploy Python applications using uv on Upsun’s platform:

Project structure

Your uv-based project should have this structure:

my-python-app/
├── .upsun/
│   └── config.yaml
├── pyproject.toml  # Created by uv
├── main.py
└── src/

Essential Upsun configuration

Create .upsun/config.yaml with uv-optimized settings:

applications:
  app:
    source:
      root: "/"
    
    type: "python:3.12"
    
    # Use uv for dependency management
    dependencies:
      python3:
        uv: "*"
    
    # uv build process
    hooks:
      build: |
        # Use uv for fast dependency installation
        uv sync --frozen
        
        # Optional: compile Python files for better performance
        # python -m compileall .        
    
    # Web server configuration
    web:
      commands:
        # We add --no-sync to prevent uv from trying to write the uv.lock at runtime 
        start: "uv run --no-sync uvicorn app:app --reload --host 0.0.0.0 --port $PORT"
    
    # uv cache optimization
    variables:
      env:
        uv_CACHE_DIR: "/tmp/uv-cache"
        PYTHONPATH: "."

routes:
  "https://{default}/":
    type: upstream
    upstream: "app:http"

Key configuration benefits

Fast builds: uv’s speed dramatically reduces deployment time compared to pip-based builds.

Dependency optimization: The uv sync --frozen command ensures reproducible builds with locked dependencies.

Cache efficiency: uv’s intelligent caching works perfectly with Upsun’s build process.

Deployment workflow

1. Initialize your project locally:

uv init my-app
cd my-app
uv add fastapi gunicorn

2. Create your application:

# main.py
from fastapi import FastAPI

app = FastAPI()

@app.get("/")
def read_root():
    return {"message": "Hello from uv on Upsun!"}

3. Deploy to Upsun:

git add .
git commit -m "Setup FastAPI with uv"
upsun push

The uv-powered build process will install dependencies in seconds rather than minutes, making your deployment pipeline significantly faster.

Conclusion

uv transforms Python development from a series of manual, time-consuming tasks into a streamlined, efficient workflow. The dramatic speed improvements alone justify adoption, but uv’s comprehensive project management capabilities make it essential for modern Python development.

The question isn’t whether you should try uv, it’s how quickly you can integrate it into your development workflow. With its backward compatibility, minimal learning curve, and transformative performance benefits, uv represents the future of Python package management.

Ready to transform your Python workflow? Deploy your Python uv app on Upsun now and experience lightning-fast builds with uv’s package management.