Python guidelines

General guidelines to improve the quality and readability of our python code. For python, see the C++ guidelines.

The Google style guide is a useful reference, but frequently too opinionated.

General

• PREFER iterating over containers to indexing containers manually
• PREFER argparse over getopt
• PREFER new style to old style string formatting, see also here
• ALWAYS use ruff-format (for new code) and ruff-check
• ALWAYS place import statements at the top of the file
• NEVER run non-trivial code at the top-level scope of your module, so that it can be imported without side-effects. INSTEAD, hide this code behind an if __name__ == "__main__": condition

FairRoot/FairShip specific

• PREFER STL vectors or RVecs or GenVector over TVectorT
• PREFER STL containers or RTensor over TMatrix
• PREFER using len() instead of .size() and .GetEntries() (supported for STL containers, TCAs, TTrees, Pythia8 events and many other data types)