Python in a Nutshell

Chapter 5. Object-Oriented Python

Python is an object-oriented programming language. Unlike some other object-oriented languages, Python doesn’t force you to use the object-oriented paradigm exclusively. Python also supports procedural programming with modules and functions, so you can select the most suitable programming paradigm for each part of your program. Generally, the object-oriented paradigm is suitable when you want to group state (data) and behavior (code) together in handy packets of functionality. It’s also useful when you want to use some of Python’s object-oriented mechanisms covered in this chapter, such as inheritance or special methods. The procedural paradigm, based on modules and functions, tends to be simpler and is more suitable when you don’t need any of the benefits of object-oriented programming. With Python, you often mix and match the two paradigms.

Python 2.2 and 2.3 are in transition between two slightly different object models. This chapter starts by describing the classic object model, which was the only one available in Python 2.1 and earlier and is still the default model in Python 2.2 and 2.3. The chapter then covers the small differences that define the powerful new-style object model and discusses how to use the new-style object model with Python 2.2 and 2.3. Because the new-style object model builds on the classic one, you’ll need to understand the classic model before you can learn about the new model. Finally, the chapter covers special ...