OpenFisca Germany

The country whose law is modelled here has a very simple tax and benefit system.

• It has a flat rate tax whose rates increase every year.
• On the first of December, 2015, it introduced a basic income for all its citizens of age who have no income.
• On the first of December, 2016, it removed the income condition, providing all its adult citizens with a basic income.

These elements are described in different folders. All the modelling happens within the openfisca_germany folder.

• The rates are in the parameters folder.
• The formulas are in the variables folder.
• This country package comes also with reforms in the reforms folder. This is optional: your country may exist without defining any reform.
  • In this country, there is a reform project aiming to modify the social security taxation, deleting the first bracket, raising the intermediary ones and adding a new bracket with a higher tax rate of 40 % for people earning more than 40000. This reform project would apply starting from 2017-01-01.

The files that are outside from the openfisca_germany folder are used to set up the development environment.

Packaging your Country Package for Distribution

Country packages are Python distributions. You can choose to distribute your package automatically via the predefined continuous deployment system on GitHub Actions, or manually.

Automatic continuous deployment on GitHub

This repository is configured with a continuous deployment system to automate the distribution of your package via pip.

Setting up continuous deployment

To activate the continuous deployment:

1. Create an account on PyPI if you don't already have one.
2. Generate a token in your PyPI account. This token will allow GitHub Actions to securely upload new versions of your package to PyPI.
3. Add this token to your GitHub repository's secrets under the name PYPI_TOKEN.

Once set up, changes to the main branch will trigger an automated workflow to build and publish your package to PyPI, making it available for pip installation.

Manual distribution

If you prefer to manually manage the release and distribution of your package, follow the guidelines provided by the Python Packaging Authority.

This involves detailed steps on preparing your package, creating distribution files, and uploading them to PyPI.

Install Instructions for Users and Contributors

This package requires Python 3.11. More recent versions should work, but are not tested.

All platforms that can execute Python are supported, which includes GNU/Linux, macOS and Microsoft Windows.

Setting-up a Virtual Environment with venv

In order to limit dependencies conflicts, we recommend using a virtual environment with venv.

• A venv is a project specific environment created to suit the needs of the project you are working on.

To create a virtual environment, launch a terminal on your computer, cd into your directory and follow these instructions:

python3 -m venv .venv # create a new virtual environment in the “.venv” folder, which will contain all dependencies
source .venv/bin/activate # activate the venv

You can now operate in the venv you just created.

You can deactivate that venv at any time with deactivate.

🎉 You are now ready to install this OpenFisca Country Package!

Two install procedures are available. Pick procedure A or B below depending on how you plan to use this Country Package.

A. Minimal Installation (Pip Install)

Follow this installation if you wish to:

• run calculations on a large population;
• create tax & benefits simulations;
• write an extension to this legislation (e.g. city specific tax & benefits);
• serve your Country Package with the OpenFisca Web API.

For more advanced uses, head to the Advanced Installation.

Install this Country Package with Pip Install

Inside your venv, check the prerequisites:

python --version  # should print "Python 3.11.xx".

pip --version  # should print at least 9.0.
# if not, run "pip install --upgrade pip"

Install the Country Package:

pip install openfisca-germany

⚠️ Please beware that installing the Country Package with pip is dependent on its maintainers publishing said package.

🎉 This OpenFisca Country Package is now installed and ready!

Next Steps

• To learn how to use OpenFisca, follow our tutorials.
• To serve this Country Package, serve the OpenFisca Web API.

Depending on what you want to do with OpenFisca, you may want to install yet other packages in your venv:

• To install extensions or write on top of this Country Package, head to the Extensions documentation.
• To plot simulation results, try matplotlib.
• To manage data, check out pandas.

B. Advanced Installation (Git Clone)

Follow this tutorial if you wish to:

• create or change this Country Package's legislation;
• contribute to the source code.

Clone this Country Package with Git

First, make sure Git is installed on your machine.

Set your working directory to the location where you want this OpenFisca Country Package cloned.

Inside your venv, check the prerequisites:

python --version  # should print "Python 3.11.xx".

Clone this Country Package on your machine:

git clone git://github.com/Citizen-Knowledge-Graph/openfisca-germany.git
cd openfisca-germany
pip install --upgrade pip build twine
pip install --editable .[dev] --upgrade

You can make sure that everything is working by running the provided tests with make test.

Learn more about tests

🎉 This OpenFisca Country Package is now installed and ready!

Next Steps

• To write new legislation, read the Coding the legislation section to know how to write legislation.
• To contribute to the code, read our Contribution Guidebook.

C. Contributing

Follow this tutorial if you wish to:

• contribute to the source code.

Note: This tutorial assumes you have already followed the instructions laid out in section B. Advanced Installation.

In order to ensure all published versions of this template work as expected, new contributions are tested in an isolated manner on Github Actions.

Follow these steps to set up an isolated environment for testing your contributions as Github Actions does.

Set up an isolated environment

First, make sur Tox is installed on your machine.

We recommend using pipx to install tox, to avoid mixing isolated-testing dependencies testing with virtualenv.

pipx install tox

Testing your contribution in an isolated environment

You can make sure that your contributions will work as expected by running:

tox

You can also run these in parallel:

tox -p

🎉 Your contribution to OpenFisca Country Package is now ready for prime time!

Next Steps

• Open a pull request to the main branch of this repository.
• Announce your changes as described in CONTRIBUTING.

Serve this Country Package with the OpenFisca Web API

If you are considering building a web application, you can use the packaged OpenFisca Web API with your Country Package.

To serve the Openfisca Web API locally, run:

openfisca serve --port 5000 --country-package openfisca_germany

Or use the quick-start Make command:

make serve-local

To read more about the openfisca serve command, check out its documentation.

You can make sure that your instance of the API is working by requesting:

curl "http://localhost:5000/spec"

This endpoint returns the Open API specification of your API.

🎉 This OpenFisca Country Package is now served by the OpenFisca Web API! To learn more, go to the OpenFisca Web API documentation.

You can test your new Web API by sending it example JSON data located in the situation_examples folder.

curl -X POST -H "Content-Type: application/json" \
  -d @./openfisca_germany/situation_examples/couple.json \
  http://localhost:5000/calculate