Poetry Python Setup

As you might know I am more of a ruby programmer. But from time to time I use different things, like Python.

That is why we talk about my Python setup today. A few things have happened since I last built some projects with Python. One of these things is Poetry and the pyproject.toml.

The Tools

Let's talk quickly about Poetry which promises: "Python packaging and dependency management made easy". The main focus is on dependency management, for example Python finally gets a dependency lock file like ruby or npm. It also handles virtual environments for you, which removes the need for virtualenv and similar tools.

And it makes use of the new pyproject.toml file. Which is one config file to configure all tools. Read more about it here: What the heck is pyproject.toml?

FlakeHell is like the old Flake we all loved, only cooler! It allows to integrate all linter into one thing and run them all together.

My Setup

Enough talk let's look at my current setup for a project. This is my pyproject.toml file.

name = "My Python Project"
version = "0.1.0"
description = "Python Project goes Brrrrrr"
authors = ["Me <email>"]
license = "BSD"

python = "^3.9"
pydantic = "*"

pytest = "*"
sphinx = "*"
flakehell = "*"
pep8-naming = "*"
flake8-2020 = "*"
flake8-use-fstring = "*"
flake8-docstrings = "*"
flake8-isort = "*"
flake8-black = "*"

minversion = "6.0"
addopts = "--ff -ra -v"
python_functions = [
testpaths = [

requires = ["poetry-core>=1.0.0"]
build-backend = "poetry.core.masonry.api"

name = "gitlab"
url = "https://$GITLAB/api/v4/projects/9999/packages/pypi/simple"

max_line_length = 100
show_source = true

multi_line_output = 3
include_trailing_comma = true
force_grid_wrap = 0
use_parentheses = true
ensure_newline_before_comments = true
line_length = 100

line-length = 100

pyflakes = ["+*"]
pycodestyle = ["+*"]
pep8-naming = ["+*"]
"flake8-*" = ["+*"]

flake8-docstrings = ["-*"]

Let's look at this in detail. We have [tool.poetry.dev-dependencies] where we list all our dev dependencies. Big surprise I know :D. First we see pytest for tests and sphinx for docs and as already mentioned at the start I use FlakeHell with these plug-ins:

Checkout awesome-flake8-extensions and choose your own adventure!

All the configuration needed for pytest is in the tag [tool.pytest.ini_options].


Did you know that GitLab can host PyPI packages in the Package Registry? Package Registry is a feature which allows to publish private pip packages into a PyPI Package Registry.

We can deploy pip packages like this for example. Where 9999 is our project id which we want to use as Package Registry.

  stage: deploy
    - tags
   - python -m pip install twine
   - python setup.py sdist bdist_wheel
   - twine upload
       --username gitlab-ci-token
       --password $CI_JOB_TOKEN
       --repository-url $CI_API_V4_URL/projects/9999/packages/pypi

And to consume the pip packages I added:

name = "gitlab"
url = "https://$GITLAB/api/v4/projects/9999/packages/pypi/simple"

Depending on your GitLab config you need some authentication for that, which you can easily do with:

poetry config http-basic.gitlab __token__ $GITLAB_TOKEN

Checkout the GitLab documentation for all the details.

How to use it

Now with all this setup in place I still create a small Makefile. Reason to create a Makefile is that this allows you to type even less.

    poetry install
    poetry run isort src tests
    poetry run black src tests
    poetry run flakehell lint src tests
    poetry run pytest

As we can see here format, lint and test become super easy because all the setup code is in pyproject.toml.