Python Poetry for Dependency Management
Poetry is a tool for dependency management and packaging in Python. It allows you to declare the libraries your project depends on and it will manage (install/update) them for you. It aims to replace setup.py, requirements.txt, setup.cfg, MANIFEST.in, and Pipfile with a simple pyproject.toml based project format.
Installation
Linux, macOS, Windows (WSL)
curl -sSL https://install.python-poetry.org | python3 -Windows (Powershell)
(Invoke-WebRequest -Uri https://install.python-poetry.org -UseBasicParsing).Content | py -Basic Usage
Initializing a Project
To create a new project:
poetry new my-projectTo initialize poetry in an existing directory:
cd my-existing-project
poetry initThis will guide you through creating a pyproject.toml file.
Adding Dependencies
To add a package to your project:
poetry add requestsTo add a development dependency (e.g., for testing):
poetry add pytest --group devInstalling Dependencies
To install the dependencies defined in pyproject.toml:
poetry installThis command reads the poetry.lock file if it exists, ensuring reproducible builds. If not, it resolves dependencies and creates the lock file.
Virtual Environments
Poetry automatically creates and manages a virtual environment for your project.
Activating the Environment
To spawn a shell within the virtual environment:
poetry shellTo run a single command within the environment without activating the shell:
poetry run python script.pyConfiguration
You can configure Poetry to create virtual environments inside the project directory (similar to venv).
poetry config virtualenvs.in-project trueThe pyproject.toml File
This is the main configuration file.
[tool.poetry]
name = "my-project"
version = "0.1.0"
description = ""
authors = ["Your Name <you@example.com>"]
[tool.poetry.dependencies]
python = "^3.9"
requests = "^2.28.1"
[tool.poetry.group.dev.dependencies]
pytest = "^7.1.2"
[build-system]
requires = ["poetry-core>=1.0.0"]
build-backend = "poetry.core.masonry.api"