Laura and Gary, thank you for your replies. I have three physical buttons connected to a Kade device emulating a keyboard. These buttons control an LED light strip. So there is no screen, so a GUI did not cross my mind. I thought it made sense as it is easily done by other scripting languages. Thank you both for pointing my in the right direction.
It turns out Tkinter is installed on Raspian and my Pi has it. Typing import tkinter into the Python interpreter gave me an error, then I corrected my spelling. The T should be upper case. No errors with "import Tkinter". Laura, thank you for typing up example code. I had to remove one indent on line 9, but after that it worked on my desktop. The Pi gave an error about Tkinter when I tried to run your code but I will work on that. In the meantime I will work my basic code out on the desktop and then move it over to the Pi, adapting it for and fixing Pi issues then. In my mind the Tkinter information I read on the web contradicts the examples given with the text, so obviously I am not getting it at all. Tkinter seems very confusing to me right now, but I think I just need to review the conceptual stuff again and keep trying. Also, I have your example, which I can experiment with. Thanks. -- https://mail.python.org/mailman/listinfo/python-list
