Chris Angelico <ros...@gmail.com>: > On Fri, Jul 7, 2017 at 7:15 PM, Marko Rauhamaa <ma...@pacujo.net> wrote: >> You can only define the semantics of Python (in this case) by >> providing an *arbitrary* mapping to an imaginary abstract machine. >> There's no way to define the objective abstraction. > > So aside from an artificial sense of purity, what's the point in > defining object identity *at all*? Why invent an arbitrary number that > you can't even see?
Without such an invisible identity, you can't specify the desired behavior of a Python program. (Well, id() returns a visible identity, which you could equate with the invisible one.) I understand that not everything should be strictly formal, but all attempts at clarifying Python's object system necessarily involve evoking some silly abstract model. The Lisp community is so old they never thought of shunning hardware concepts (storage, pointers, Common Address Register, Common Data Register etc). There doesn't seem to be any better way for Python, either. It might be easiest to say that every Python object has an address and id() returns it. Even if you were lying, nobody would be able to call your bluff. Then, explaining objects to newcomers would be a bit more straightforward. Marko -- https://mail.python.org/mailman/listinfo/python-list
