Dynamic subclassing ?

[manatlan]

On 12 mai, 18:38, "Daniel Nogradi" <nogr... at gmail.com> wrote:
> > I've got an instance of a class, ex :
>
> > b=gtk.Button()
>
> > I'd like to add methods and attributes to my instance "b".
> > I know it's possible by hacking "b" with setattr() methods. But i'd
> > like to do it with inheritance, a kind of "dynamic subclassing",
> > without subclassing the class, only this instance "b" !
>
> > In fact, i've got my instance "b", and another class "MoreMethods"
>
> > class MoreMethods:
> >     def  sayHello(self):
> >           print "hello"
>
> > How could i write ...
>
> > "b = b + MoreMethods"
>
> > so "b" will continue to be a gtk.Button, + methods/attributs of
> > MoreMethods (it's what i call "dynamic inheritance") ...so, things
> > like this should work :
>
> > - b.set_label("k")
> > - b.sayHello()
>
> > I can't find the trick, but i'm pretty sure it's possible in an easy
> > way.
>
> How about:
>
> class MoreMethods:
>     def  sayHello(self):
>         print "hello"
>
> class myButton( gtk.Button, MoreMethods ):
>     pass
>
> b = myButton( )
>
> isinstance( b, gtk.Button )  # True
> b.sayHello( )  # "hello"

yes, but it needs to recreate an instance (of mybutton) ...
i can't do that, in my context.
The only things i've got is my instance "b" (which can be whatever
object).
i'd like to add methods/attributes to this instance, by adding a
heritage of another class.

> Daniel
thanks