[nmstoker]

All good points. Perhaps a passing reference with a link back to the intro chapter (or wherever it's covered) in the chapters where it's used, since it's easier to dip into one of the later graphics chapters without having seen the intro.

[bddicken]

Yeah, graphics.py refers to my custom TKinter wrapper, which I would have my students use for a few of the course projects. I can improve things so that it is easier to find from lessons other than basic shapes.