Turning a callback function into a generator

[Kirk McDonald]

Let's say I have a function that takes a callback function as a 
parameter, and uses it to describe an iteration:

def func(callback):
     for i in [1, 2, 3, 4, 5]:
         callback(i)

For the sake of argument, assume the iteration is something more 
interesting than this which relies on the callback mechanism. The 
function is an existing interface, and I cannot change it.

I want to somehow, in some way, provide an iteration interface to this 
function. Thoughts?

-Kirk McDonald