We have now come to the part where we want to design how our application will look and feel. For this graphical user interface (GUI), we take the path of least resistance and go with the Tkinter library since this is a standard built-in library in the official Python installations, at least for Windows and Mac. Other reasons for choosing Tkinter is that it is fairly easy to use and is slightly more Pythonic than some of the newer third-party GUI libraries.

If you have not used Tkinter before, you should still be able to follow along. The basic idea of Tkinter is that you create widget classes for each graphical element of your GUI, defining their look and placement. Complex elements can be created by nesting widgets within widgets. You can also bind functions to user interaction events.