Chapter 4 gives an application of Python to the web. It does not introduce new language features. We have come to end of the new language features in this tutorial, but there are certainly more basic topics to learn about programming and Python in particular, if you continue in other places:
Beyond these language features, Python has a vast collection of useful modules. An example program, bbassign.py, is a real-world program that I have in regular use for processing inconveniently organized files created by Blackboard for homework submissions. It is a command-line script that uses string methods and slicing and both kinds of loops, as well is illustrating some useful components in modules sys, os, and os.path, for accessing command line parameters, listing file directories, creating directories, and moving and renaming files.