# Create new project with complete structure
uv init my-project
cd my-project

# Initialize in existing directory
uv init

# Initialize with specific Python version
uv init --python 3.11 my-app

# Add dependencies
uv add requests
uv add 'flask>=2.0'
uv add 'django>=4.0,<5.0'

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

# Add optional dependency groups
uv add --group docs sphinx sphinx-rtd-theme

# Remove dependencies
uv remove requests flask

# Migrate from requirements.txt
uv add -r requirements.txt

# Create/update lockfile (uv.lock)
uv lock

# Lock with upgraded packages
uv lock --upgrade-package requests
uv lock --upgrade

# Lock without installing (CI/CD)
uv lock --frozen

# Sync environment to lockfile
uv sync

# Sync without updating lockfile
uv sync --frozen

# Error if lockfile is out of date
uv sync --locked

my-project/
├── pyproject.toml      # Project metadata and dependencies
├── uv.lock            # Locked dependency versions
├── .venv/             # Virtual environment (auto-created)
├── README.md
└── src/
    └── my_project/
        └── __init__.py

[project]
name = "my-project"
version = "0.1.0"
description = "Add your description here"
readme = "README.md"
dependencies = []

[build-system]
requires = ["uv_build>=0.9.2,<0.10.0"]
build-backend = "uv_build"

uv init my-app && cd my-app
uv add ruff pytest
uv run pytest

# Production dependencies
uv add fastapi uvicorn 'pydantic>=2.0'

# Development tooling
uv add --dev pytest pytest-cov ruff ty

# Documentation
uv add --group docs sphinx mkdocs-material

# Update specific package
uv lock --upgrade-package requests

# Update all dependencies
uv lock --upgrade

# Sync after update
uv sync