object changing itself to another object

[Glen Murphy]

I'm creating a program that takes user input, and passes it to an object -
however, I want that object itself, and not the parent to change where that
input goes. In the highly simplified example below, I would like the output
to be "Obj1","Obj2","Obj1" - but not suprisingly, I just get Obj1, Obj1,
Obj1


### code begin  ###

class Obj1:
    def key1(self):
        # do obj1 specific stuff
        self = Obj2()
        print "Obj1"

class Obj2:
    def key1(self):
        # do obj1 specific stuff
        self = Obj1()
        print "Obj2"

a = Obj1()

# simulate user keypresses
a.key1()
a.key1()
a.key1()

### code end ###

I know I could achieve the result I want by doing horribly complicated trees
of ifs and such, but I'd like my code to be nice and expandable (in this
example, to easily add new Objs). I've looked through the Python FAQ, Google
Groups and Various O'Reilly books, but I don't really know the terminology
for what I'm looking for, so I haven't found anything so far, so does anyone
have any pointers?

Any help would be greatly appreciated,
Cheers,
Glen

--
Glen Murphy, http://glenmurphy.com/