Finding the instance reference of an object

[Joe Strout]

On Nov 3, 2008, at 12:00 PM, Aaron Brady wrote:

> I think we can conclude that Python passes by reference, since a
> function can modify objects that were passed in to it.

Then please write the Python equivalent of the "Swap" methods shown at  
<http://www.strout.net/info/coding/valref/> (or at <http://javadude.com/articles/passbyvalue.htm 
 >, for that matter).

And no fair wrapping the two parameters up in an object or using tuple  
packing/unpacking -- the point is to demonstrate that you can change  
the two parameters themselves, not some object that contains them or  
return them a different order.

And by the way, if mutating an object a parameter refers to qualifies  
as pass by reference, then Java, VB.NET/REALbasic (in ByVal mode), and  
C/C++ all pass by reference too.  That'll be quite a surprise to their  
compiler authors!  (I should know, as I'm one of them.)

Best,
- Joe