The Golden Rule

Finally, if all these points can be distilled into a single, overarching philosophy, it is this:

If you're writing code to trace code, you're probably solving the wrong problem. Use the tools that already exist.

This is your ultimate sanity check. The moment you find yourself writing a decorator, a context manager, or an AST transformer for the purpose of understanding another piece of code, a red flag should go up. It's a signal that you have likely skipped a step in the hierarchy of tools. You're trying to build a hammer when a whole box of professional-grade, perfectly-suited hammers is sitting right next to you, ready to be used. Stop, reset your approach, and find the existing tool. Your time is too valuable to spend reinventing the wheel.