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Python guidelines

For any Python code, please stick to the guidelines described in this section.

Python version

For any new projects, please use one of the two most recent Python minor versions. For existing projects, use the Python version used throughout the project.

Code formatting

Please format the code using black and default parameters. Where black is not prescriptive, please use a consistent coding style. In particular, when contributing to an existing code base, please adhere to the coding style you find. In all cases, please adhere to PEP 8.


Please add Google-style docstrings to all modules, functions and methods. Follow PEP 257. Do not include types in the docstrings.

Type hints

Add type hints to all function and method signatures, as well as any global variables. Adding type hints to local variables is recommended. Adding type hints to (unit) tests is not necessary.

Linters & static type checkers

Please make use of the following tools with default parameters to make sure your code is of good quality:

When disabling rules is required, it is preferable to do so in-line, rather than globally.


Use pytest as a test runner for unit tests. You can determine the test coverage with the coverage package. Strive for a test coverage of 100% for new projects. Proposed code changes should never reduce the previous test coverage.