This is a pretty simple and useful feature. I wouldn’t say that it bloats the language too much. Descriptors and metaclasses are much more complicated and have a lot more implications and have been in the language for a veeeeery long time. Is it decades already?
This feature is not complicated, but one must keep every feature that can possibly be seen in code in their head. Even if it is familiar now, what happens when you use the feature in the one small section of code where it fits, nowhere else, and then read that code 2 years later? This is the problem with adding useful features that are only used in a few key places. I'm not saying Go is a perfect language, far from it, but limiting # of features as a general goal is something more languages should strive for IMO.
I am not arguing against that language ideally should have less features. I am arguing with “Python is getting huge”, because it’s huge and has been for many-many years :)
Yeah, Python hasn’t been a simple language for a long time, if ever. That’s probably the biggest misconception about the language - that its friendly syntax implies simple semantics. It’s not true at all.
I would say python in it's entirety is one of, if not the deepest and potentially most complex language I know. C++ is the other contender. The things you could do with metaclasses, multiple inheritance and operator overloading are quite staggering.
I'm just glad you don't have to think or even use this as a normal user of the language, most of the time or at all.
A lot of Python's complexity like descriptors and metaclasses and the so-called cooperative multiple inheritance come from an era where object orientation is gospel and yet people keep finding limitations to what can be accomplished in an OO paradigm and therefore they patch up the language to support ever more complicated use cases.
I have a feeling that if metaclasses and descriptors were to be proposed today it would be laughed out of the PEP process completely.
> I have a feeling that if metaclasses and descriptors were to be proposed today it would be laughed out of the PEP process completely.
I think you need at least one of these. Modern Python eschews metaclasses but descriptors are everywhere. Without them you couldn’t have @classmethod, @staticmethod nor @property - or at least, you couldn’t generalise custom method lookup and all three of those would need to be special cases.
The alternative approach is to drop descriptors and make method lookup much simpler, but then you need metaclasses (see: static methods in Ruby).
If descriptors didn't exist in the language, classmethod, staticmethod, and property would become keywords. Languages like Java and C++ already have static as a keyword; C++ also made its type system have a special pointer to member type; such behavior can be hardcoded without having a flexible descriptor mechanism.
Custom method lookup would just be the same as custom attributes, that is, by the user overriding __getattr__.
