object vs class oriented -- xotcl

[Guilherme Polo]

2008/1/24, William Pursell <bill.pursell at gmail.com>:
>
> I've been away from Python for at least a year, and in the interim
> have spent a little time looking at the XOTcl object framework for
> Tcl.  One of the interesting features of XOTcl is the ability for an
> object to change class dynamically.  The XOtcl documentation makes the
> claim that this makes it object oriented, while most other languages
> are "class oriented".  Here's a snippet from the wiki, from a post to
> the mailing list by Gustaf Neumann: (http://wiki.tcl.tk/1297)
>
> Class-oriented means: look at the class and you know exactly how all
> of the instances look alike. The class is the first and primary
> language construct; the class is well the place where you specify the
> instance variables (there are no instance variables except those
> specified in the class). The only kind of individualism left in the
> objects is to let them differ by their state (the values of their
> instance variables). Changing classes (class migration) is
> conceptually quite hard for this setup.
>
> Object-oriented (in this distinction) means that the primary elements
> are objects, which keep all instance variables. classes my be used to
> specify the behavior of objects, they are container for methods and
> they control the life-cycle of objects. Objects are like the facts,
> and classes are like rules, that determine the behavior of the
> objects. Since the connection between objects and classes is rather
> loose, it is sufficient to define their relation through an
> association. Therefore it is quite easy to change the relation between
> objects and classes (and between classes and classes) dynamically.
> Objects have arbitrary individualism, they may have variables never
> used in any class, they may have private procs etc.
>
> I'm not sure that describes the method well.  Basically, you can
> instantiate an object A of class Foo, and later change A to be an
> object of class Bar.   Does Python support this type of flexibility?
> As I stated above, I've been away from Python for awhile now, and am a
> bit rusty,  but it seems that slots or "new style" objects might
> provide this type of behavior.  The ability to have an object change
> class is certainly  (to me) a novel idea.  Can I do it in Python?
> --
> http://mail.python.org/mailman/listinfo/python-list
>

class A(object): pass
class B(object): pass

a = A()
a.__class__ = B

That ? Maybe you meant something else.

-- 
-- Guilherme H. Polo Goncalves