On Fri, Jul 7, 2017 at 9:48 PM, Marko Rauhamaa <ma...@pacujo.net> wrote: > 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.
"x is y" returns True if and only if x and y refer to the same object. You have yet to demonstrate that the above statement is underspecified. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
