Managing dependencies Dependency groups Poetry provides a way to organize your dependencies by groups. For instance, you might have dependencies that are only needed to test your project or to build the documentation. To declare a new dependency group, use a tool.poetry.group.<group> section where <group> is the name of your dependency group (for instance, test): [tool.poetry.group.test] # This part can be left out [tool.poetry.group.test.dependencies] pytest = "^6.0.0" pytest-mock = "*" Note All dependencies must be compatible with each other across groups since they will be resolved regardless of whether they are required for installation or not (see Installing group dependencies).

Introduction 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. Poetry offers a lockfile to ensure repeatable installs, and can build your project for distribution. System requirements Poetry requires Python 3.8+. It is multi-platform and the goal is to make it work equally well on Linux, macOS and Windows.

Community Badge For any projects using Poetry, you may add its official badge somewhere prominent like the README. Markdown [](https://python-poetry.org/) reStructuredText .. image:: https://img.shields.io/endpoint?url=https://python-poetry.org/badge/v0.json :alt: Poetry :target: https://python-poetry.org/

Basic usage For the basic usage introduction we will be installing pendulum, a datetime library. If you have not yet installed Poetry, refer to the Introduction chapter. Project setup First, let’s create our new project, let’s call it poetry-demo: poetry new poetry-demo This will create the poetry-demo directory with the following content: poetry-demo ├── pyproject.toml ├── README.md ├── poetry_demo │ └── __init__.py └── tests └── __init__.py The pyproject.toml file is what is the most important here. This will orchestrate your project and its dependencies. For now, it looks like this:

Dependency specification Dependencies for a project can be specified in various forms, which depend on the type of the dependency and on the optional constraints that might be needed for it to be installed. project.dependencies and tool.poetry.dependencies Prior Poetry 2.0, dependencies had to be declared in the tool.poetry.dependencies section of the pyproject.toml file. [tool.poetry.dependencies] requests = "^2.13.0" With Poetry 2.0, you should consider using the project.dependencies section instead. [project] # ... dependencies = [ "requests (>=2.23.0,<3.0.0)" ] While dependencies in tool.poetry.dependencies are specified using toml tables, dependencies in project.dependencies are specified as strings according to PEP 508.

Dependency specification Dependencies for a project can be specified in various forms, which depend on the type of the dependency and on the optional constraints that might be needed for it to be installed. project.dependencies and tool.poetry.dependencies Prior Poetry 2.0, dependencies had to be declared in the tool.poetry.dependencies section of the pyproject.toml file. [tool.poetry.dependencies] requests = "^2.13.0" With Poetry 2.0, you should consider using the project.dependencies section instead. [project] # ... dependencies = [ "requests (>=2.23.0,<3.0.0)" ] While dependencies in tool.poetry.dependencies are specified using toml tables, dependencies in project.dependencies are specified as strings according to PEP 508.

Repositories Poetry supports the use of PyPI and private repositories for discovery of packages as well as for publishing your projects. By default, Poetry is configured to use the PyPI repository, for package installation and publishing. So, when you add dependencies to your project, Poetry will assume they are available on PyPI. This represents most cases and will likely be enough for most users. Private Repository Example Installing from private package sources By default, Poetry discovers and installs packages from PyPI. But, you want to install a dependency to your project for a simple API repository? Let’s do it.

Managing environments Poetry makes project environment isolation one of its core features. What this means is that it will always work isolated from your global Python installation. To achieve this, it will first check if it’s currently running inside a virtual environment. If it is, it will use it directly without creating a new one. But if it’s not, it will use one that it has already created or create a brand new one for you.

Libraries This chapter will tell you how to make your library installable through Poetry. Versioning Poetry requires PEP 440-compliant versions for all projects. While Poetry does not enforce any release convention, it used to encourage the use of semantic versioning within the scope of PEP 440 and supports version constraints that are especially suitable for semver. Note As an example, 1.0.0-hotfix.1 is not compatible with PEP 440. You can instead choose to use 1.0.0-post1 or 1.0.0.post1. Lock file For your library, you may commit the poetry.lock file if you want to. This can help your team to always test against the same dependency versions. However, this lock file will not have any effect on other projects that depend on it. It only has an effect on the main project.

Configuration Poetry can be configured via the config command (see more about its usage here) or directly in the config.toml file that will be automatically created when you first run that command. This file can typically be found in one of the following directories: macOS: ~/Library/Application Support/pypoetry Windows: %APPDATA%\pypoetry For Unix, we follow the XDG spec and support $XDG_CONFIG_HOME. That means, by default ~/.config/pypoetry. Local configuration Poetry also provides the ability to have settings that are specific to a project by passing the --local option to the config command.