On Fri, Jun 25, 2021 at 3:31 AM Steven D'Aprano <st...@pearwood.info> wrote: > > Here's a quick and dirty proof of concept I knocked up in about 20 > minutes, demonstrating that no deep compiler magic is needed. It's just > a small change to the way `object.__getattribute__` works. > > I've emulated it with my own base class, since `object` can't be > monkey-patched. > > The proof of concept is probably buggy and incomplete. It isn't intended > to be a final, polished production-ready implementation. It's not > implementation-agnostic: it requires the ability to inspect the call > stack. If you're using IronPython, this may not work. > > You will notice I didn't need to touch getattr to have it work, let > alone hack the interpreter to make it some sort of magical construct. It > all works through `__getattribute__`. > > The registration system is just the easiest thing that I could throw > together. There are surely better designs. > > Run A.py to see it in action. >
Okay, so you've hidden the magic away a bit, but you have to choose the number [2] for your stack inspection. That means you have to be sure that that's the correct module, in some way. If you do *anything* to disrupt the exact depth of the call stack, that breaks. _hasattr = hasattr def hasattr(obj, attr): return _hasattr(obj, attr) Or any of the other higher level constructs. What if there's a C-level function in there? This is still magic. It's just that the magic has been buried slightly. ChrisA _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/RPBIHJE3SHL7S6XIS2343SXCOTW5C54A/ Code of Conduct: http://python.org/psf/codeofconduct/
