Summary
Design patterns are reusable, somewhat language-specific solutions to common problems in software design. They are a part of the culture of all developers, no matter what language they use.
So, using implementation examples for the most used patterns for a given language is a great way to document that. Both on the Web and in other books, you will easily find implementation for every design pattern mentioned in GoF books. This is why we concentrated only on patterns that are the most common and popular in the context of the Python language.