human
Can you provide a Python program to print 'session    connected:    {}' given the following:
I wrote the below code

    print 'session    connected:    {}'.format(session)
    def on_leave(details):
        print ('on_leave', details)
    session.on_leave(on_leave)
    session.leave()

What's a good function header?
assistant
#Here is Python program to print 'session    connected:    {}'.

def on_join(session):