Can I reference 1 instance of an object by more names ?

[Bruno Desthuilliers]

Stef Mientki a écrit :
> hello,
> 
> I'm trying to build a simple functional simulator for JAL (a Pascal-like 
> language for PICs).
> My first action is to translate the JAL code into Python code.
> The reason for this approach is that it simplifies the simulator very much.
> In this translation I want to keep the JAL-syntax as much as possible 
> intact,
> so anyone who can read JAL, can also understand the Python syntax.
> 
> One of the problems is the alias statement, assigning a second name to 
> an object.
> I've defined a class IO_port,
> and I create an instance of that port with the name port_D
> 
>     port_D = IO_port('D')
> 
> Now I want to assign a more logical name to that port,
> (In JAL: "var byte My_New_Name IS port_D")
> 
> Is that possible ?
> 
> I think the answer is "no",
> because the object itself is not mutable.
> Am I right ?

You're wrong. The fact that an object is mutable or not is totally 
irrelevant here. In Python, 'variables' are in fact name=>ref_to_object 
pairs in a namespace (while this may not always be technically true, you 
can think of namespaces as dicts). So the name is nothing more than 
this: a name. And you can of course bind as many names as you want to a 
same object.

port_D = IO_port('D')
foo = port_D
bar = foo
bar is port_D
=> True