Manage Your Python Project Using Poetry

Posted on Mar 02, 2019 in Computer Science

Things under legendu.net/outdated are outdated technologies that the author does not plan to update any more. Please look for better alternatives.

uv (implemented in Rust) is the new cool kid now and is prefer to poetry.

Tips and Traps

Python Poetry is current the best project management tool for Python!
Python Poetry supports Python package dependencies on GitHub. For example, if a Python package depends on https://github.com/dclong/dsutil, then you can add it using the following.
```
poetry add git+https://github.com/dclong/dsutil.git
```
Or
```
poetry add git+ssh://git@github.com/dclong/dsutil.git
```
For more details, please refer to poetry add and git dependencies .
poetry install removes non needed libraries. A tricky situation is that if you have dependency A which depends on dependency B, and you have specified both A and B in pyproject.toml. Removing dependency B from pyrpoject.toml and then running poetry install won't remove the library B from the virtual environment as B is still needed by A.
Poetry has lots of issues in Windows currently. It is suggested that you avoid using poetry in Windows.
If you encounter the following error message when running poetry install,

[Errno 2] No such file or directory: '/path/to/readme.md'

it means that you have specified tool.poetry.readme to be readme.md in pyproject.toml but readme.md does not exists under root directory of the project.

Install Python Poetry

Follow the official tutorial.

Using xinstall.

# install xinstall if it hasn't been installed
sudo pip3 install -U git+https://github.com/dclong/xinstall@master
# install poetry using xinstall
xinstall pt -ic

Updating Python Poetry

Updating poetry to the latest stable version is as simple as calling the self:update command.

poetry self:update

If you want to install prerelease versions, you can use the --preview option.

poetry self:update --preview

Usage

Create/Initialize a New Project

Create a new Python project using poetry.
```
poetry new proj
```
Initialize an existing Python project using poetry.
```
poetry init
```

Install Dependencies

Installl all dependencies.
```
poetry install
```
Installl all but dev dependencies.
```
poetry install  --no-dev
```

Export Dependencies

Export the lock file to requirements.txt so that the dependency can be installed using pip.
```
poetry export -f requirements.txt > requirements.txt
```

Run Commands in the Virtual Environment

poetry run cmd is a quick to run cmd using the virtual environment managed by poetry. Another way is to manually setPATHbefore you invokecmd`. For example,

PATH=.venv/bin:$PATH cmd

Run test suits using pytest.
```
poetry run pytest
```
Or if you want to make it specific to collect test suits from the test directory under the root directory of the project.
```
poetry run pytest test
```
Run pytype.
```
poetry run pytype .
```

User Tasks

https://github.com/sdispater/poetry/pull/591

https://github.com/sdispater/poetry/issues/241

Configuration

https://python-poetry.org/docs/cli/#config

https://python-poetry.org/docs/configuration/

Pleaser refer to pyproject.toml for examples of configuration for Python Poetry.

Restrict Operating Systems in Python Poetry

How can I specify dependencies on operating system in Python Poetry?

[tool.poetry]
# ...
classifiers = [
    "Operating System :: POSIX :: Linux",
]

https://python-poetry.org/docs/pyproject/#classifiers

https://pypi.org/classifiers/

https://github.com/python-poetry/poetry/issues/738

https://github.com/python-poetry/poetry/issues/3356

References

https://github.com/sdispater/poetry/issues/522

https://github.com/sdispater/poetry/issues/655

https://github.com/sdispater/poetry/issues/621

Poetry Documentation

https://codingdose.info/2018/08/02/develop-and-publish-with-poetry/

https://hackersandslackers.com/poetic-python-project-packaging/