Last time, I assembled a Python object ... the simplest example. Make a button and close the program when you push it. The mainloop call handles the event loop common in GUI programs.

Putting a GUI ... due to Python’s ability to run code without a slow compiling step. There are other approaches to this problem, too – with MyOpenLab being a particularly versatile example.

We've built a few of those (like the simple To-Do List using Python). For this one, I wanted to use some GUI, so I decided we'll be importing the Tkinter library to have some usable UI elements.