Learning Python, 6th Edition

Chapter 29. Class Coding Details

If you haven’t quite grasped all of Python OOP yet, don’t worry—now that we’ve taken a first pass, we’re going to dig a bit deeper and study the concepts introduced earlier in further detail. In this and the following chapter, we’ll take another look at class mechanics. Here, we’ll study classes, methods, and inheritance, formalizing and expanding on some of the coding ideas introduced in Chapter 27 and demoed in Chapter 28. Because the class is our last namespace tool, we’ll summarize Python’s namespace and scope concepts as well.

If you’ve been reading linearly, some of this chapter will be partly review and summary of topics introduced in the preceding chapter’s case study, revisited here by language topics with self-contained examples that may help readers new to OOP. While you may be tempted to skip some material here, it includes extra details worth a browse and unveils more subtleties in Python’s class model along the way.

The next chapter continues this in-depth second pass over class mechanics by covering one specific aspect: operator overloading. First, though, let’s fill in more of the Python OOP picture.

The class Statement

Although the Python class statement may seem similar to tools in other OOP languages on the surface, on closer inspection, it is quite different from what some programmers may be used to.

For example, as in C++, the class statement is Python’s main OOP tool, but unlike in C++, Python’s class is not a declaration. ...