[pansa2]

> I dont consider prototypes-based OO a real OO.

Fair enough - in some ways it’s like half-way to an OO system. Yes, it’s theoretically elegant to have everything be an object and not to have classes. However in the vast majority of cases it seems prototype-based OO is only used as a foundation upon which to build a class system.

> What I think is rather unidiomatic in OO langs is Pythons "function/methods" like `len(x)` which is implemented as `__length__()`.

AFAIK the reason for the double-underscore method for `len` is to avoid it accidentally working for, say, a Rectangle class that exposes `length` and `width`.