active object in python for s60

How do I use active object in python for s60? can anybody give me a code example?

There's a simple example here:

def run(self):
    self.lock = e32.Ao_lock()
    self.lock.wait()
    # restore old title etc. and finish

def exit_callback(self):
    # unlocks the application and lets it finish
    self.lock.signal()

and that same URL also contains a detailed explanation (and more info, tutorial and otherwise, on Python for S60).