Op 04-09-17 om 15:24 schreef Steve D'Aprano: > I accept that many people dislike, or do not understand, conceptual models > where > objects can be in more than one location at once. For many people, dropping > into the implementation and talking about references is easier to understand. > But that doesn't make it essential. > > The semantics of Python is that we assign objects to names, not references to > objects to names. There's no "get reference" or "address of" operation in > Python. We write:
What does that mean assigning objects to names? >> Its because pointers have been de-first-classed (from C say, as a starting >> point) that the disagreements arise: - One bunch feel that since they've been >> de-first-classed they've been removed > Pointers are not merely second-class values, like functions and procedures in > Pascal, or strings in C. They're not values *at all*. > > Its not just that Python doesn't allow you to return a pointer from a > function, > or pass a pointer to a function as argument. You cannot dereference a pointer > either, or get a pointer to an object at all. (Although you can emulate > pointers in Python using objects.) > > > For more about first-class values, see this Stackoverflow thread: > > https://stackoverflow.com/questions/2578872/about-first-second-and-third-class-value > > We can quibble whether Pascal functions are first-, second- or > first-and-a-half > class values, or whether "third-class" even makes sense, but pointers, and > references, are not values of *any* class in Python. > > > > -- https://mail.python.org/mailman/listinfo/python-list
