In Python's tkinter, 'self' is a 'name tag used to point to the object (component or screen) that you are currently operating on.'The reason 'self' is necessary is so that multiple buttons or screens ...

Code below has 1 major and 1 minor problem. Major issue is, once you push the button it visually stays pushed. Minor problem is, I run this in Cygwin. I've got an rxvt window behind the Tk window.