Matthias writes:

My name is Matthias and I am 7 years old and I like Python. I knew a little about Python before I read your book, but I am learning more by reading your book. I like your book.

I think on page 202 is a little mistake. You wrote:

"We'll use this new object variable in the draw function to see if the ball has hit the top or bottom of the canvas:"

Shouldn't it be "left or right sides of the canvas" instead?

Hi Matthias. You're doing well to have gotten as far as you have, at 7 years of age. Well done!

You're absolutely right about the mistake, and I've updated the errata accordingly. Thanks very much for the "bug report". ツ