This book assumes that you have a working knowledge of the Python programming language, specifically, Version 3.4 or higher of that language. If you don't have Python already, you can download the complete language toolkit and library from http://www.python.org/, as a single easily-installed package.
You'll also require your favorite text editor, preferably one that has language support for Python. Popular choices for editors include emacs, Vim, Geany, gedit, and Notepad++. For those willing to pay, TextMate and Sublime are popular.
Note
Some of these popular editors are somewhat... exotic. They have their own operating idiom, and don't behave like any other program you might have used. They're popular because they are highly functional; they may be weird, though. If you find that one editor doesn't suit you, just pick a different one.