A lot of that is coding style. I’ve also seen a lot of hard-to-debug issues in Python caused by reflection, weird decorators that muck around with name-mangled symbols, and bytecode manipulation. You can even manipulate the traceback object so it’s more difficult to make sense of why the exception comes from.

It took me quite a long time to accept that the recommended unit testing library manipulates bytecode so that the exception message for `assert a == b` prints the values for both.