Mark Elston (132) [Avatar] Offline
At least in the first several listings of chapter 2.

I personally don't like snake case as it is a pain to type, but, if you are going to use it make sure it shows up in the listings in the book. We have things like:
from vector drawing import *
dino vectors = [(6,4), (3,1), (1,2), (-1,5), (-2,5),
# add the 16 remaining vectors here

At least, this is how it appears in the PDF file. If I copy/paste the listing then the underscores appear.