Package Management & Astral's uv

A Package is a collection of related modules grouped inside a folder. The official repository where developers publish Python packages is called PyPI (Python Package Index).

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16.3.1 Installing Packages with pip

pip is the default package manager built into Python. You can search, download, and install external libraries using single terminal commands:

# Install a package (e.g., requests)
pip install requests

# Install a specific version
pip install requests==2.31.0

# Export installed packages list to a file
pip freeze > requirements.txt

# Install all packages listed in requirements.txt
pip install -r requirements.txt

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16.3.2 The Modern Standard: Astral's uv

In professional AI engineering setups, developers are replacing standard pip and venv tools with uv (an ultra-fast Python package installer and resolver written in Rust).

• Why uv? It is up to 10-100x faster than pip and manages python versions, virtual environments, and project configurations automatically under a single tool.

Core uv Workflow Commands:

1. Initialize a new project:

   uv init my-project

   This automatically creates a standard directory structure along with a config file named pyproject.toml (which replaces requirements.txt and manages configuration settings in one place).

2. Add a package:

   uv add requests

   (This automatically creates a virtual environment folder .venv if one does not exist, downloads the package, and updates the pyproject.toml dependencies file).

3. Run scripts safely:

   uv run python main.py

   (This runs your script utilizing the project's isolated environment automatically without requiring you to run manual activation scripts).

4. Manage global tool CLI tools:

   uv tool install black