Poetry

• Python Dependency Management

Overview Poetry is a modern tool for dependency management and packaging in Python. It provides a deterministic way to manage libraries, virtual environments, and project metadata in a single pyproject.toml file.

Why use Poetry?

• Dependency Resolution: It has a robust solver that handles conflicts (Version Hell) gracefully.
• Lockfile: Generates poetry.lock to ensure all developers (and prod) use the exact same package versions.
• Packaging: Makes publishing to PyPI trivial (poetry publish).

Basic Commands

**Start new project**
poetry new my-app

**Add a library**
poetry add pandas
**(Automatically updates pyproject.toml, installs to venv, updates lockfile)**

**Developer Tools**
poetry add --group dev black pytest

**Run**
poetry run python main.py

**Shell**
poetry shell

vs Pip

• Pip: Just installs. Doesn't lock dependencies effectively (recursive dependencies often float).
• Poetry: Full project management.

It is the closest thing Python has to npm or cargo.