On Jan 9, 4:01 am, Steven D'Aprano <st...@remove-this- cybersource.com.au> wrote: > On Thu, 08 Jan 2009 18:33:50 +0000, Mark Wooding wrote: > > [Steven's message hasn't reached my server, so I'll reply to it here. > > Sorry if this is confusing.] > > > Aaron Brady <castiro...@gmail.com> wrote: > >> On Jan 8, 1:45 am, Steven D'Aprano > >> <ste...@remove.this.cybersource.com.au> wrote: > >> > On Wed, 07 Jan 2009 10:17:55 +0000, Mark Wooding wrote: > > >> > > The `they're just objects' model is very simple, but gets tied up > >> > > in knots explaining things. The `it's all references' model is > >> > > only a little more complicated, but explains everything. > > >> > But it *over* explains, because it implies things that "everybody > >> > knows" about references in other languages that aren't true for > >> > Python. > > > I addressed this elsewhere. Summary: `pass-by-reference' is a different > > thing to `all you manipulate are references': > > You know, I've written a fair bit of Python code over the years, and I've > never manipulated a reference *once*. Ints, strings, floats, lists, > tuples... but references? Never. snip > That's why we should try to keep the different layers of explanation > separate, without conflating them. Python programmers don't actually flip > bits, and neither do they manipulate references. Python programmers don't > have access to bits, or references. What they have access to is objects. snip > >> > How do we deal with anonymous objects in your model? > > What I am pretty sure of is that references are going to have to enter > > the picture at some point, because other models get too complicated. > > Well, I dare say that at *some* point all models are insufficient. The > map is not the territory, and there's always something that gets left > out. But I think your model with strings is more complicated: robots, > sticky Blu-Tack, string that you can't touch or see, and so forth. > Compared to that, TARDIS technology enabling objects to be in two places > at once is remarkably straightforward. Despite it being physically > unrealistic, it's logically simple. > > -- > Steven
Possible compromise. You can think of functions as mutation-only. You pass the object, and it gets a new (additional) name. The old name doesn't go in. </compromise> Regardless, IMO, references don't add any explanatory power; they just make you feel cocky that you know what they are. M: If 'fun()' returned a reference, you would be able to assign to it. m: You can't assign to it. C: It doesn't return a reference. -- Why can't I assign to a function call? -- Python variables are references only. -- Ok, why can't I assign to a function call? -- [Explanation Steven is trying to give.] In other words, Mark and Joe, cut to the chase. You're shirking. -- http://mail.python.org/mailman/listinfo/python-list
