We are reusing much of the same code from example2.py. We are just going to use a different method of arranging the window than using .pack(). label2 = tk.Label(window, image=dogphoto, borderwidth=3, ...

Otherwise, argparse library won't work. Compatibility for older versions in the making. --tutorial and --exercise are boolean arguments. Type the argument without any value (as in example above) for ...