Also, to make it easier to follow, I made use of the Sphinx "ifconfig" feature to separate the text into two parallel editions: a Python edition and a Java edition. A little language-specific focus may help.
Interestingly, I got an email recently from someone who wanted the entire source code for the projects described in the book. I was a little puzzled. Providing the source would completely defeat the purpose of the book, which is to build skills by actually doing the work. So, no, there is no source code available for these exercises. The point is to do the work, all the work, all by yourself.