This Book's Style and Structure

Much of this book is based on training materials developed for a three-day hands-on Python course. You'll find exercises at the end of the last chapter of the core language parts, with solutions to all exercises in Appendix B. The exercises are designed to get you coding right away, and are usually one of the highlights of the course.

We strongly recommend working through the exercises along the way, not only to gain Python programming experience, but also because some exercises raise issues not covered elsewhere in the book. The solutions in Appendix B should help if you get stuck (and we encourage you to "cheat" as much and as often as you like). Naturally, you'll need to install Python to run the exercises.

Because this text is designed to introduce language basics quickly, we've organized the presentation by major language features, not examples. We'll take a bottom-up approach here: from built-in object types, to statements, to program units, and so on. Each chapter is fairly self-contained, but later chapters use ideas introduced in earlier ones (e.g., by the time we get to classes, we'll assume you know how to write functions), so a linear reading makes the most sense. From a broader perspective, this book is divided into the following functional areas, and their corresponding parts.

Core Language

This portion of the book presents the Python language, in a bottom-up fashion. It is organized with one part per major language feature—types, functions, and so forth—and most of the examples are small and self-contained (some might also call the examples in this section artificial, but they illustrate the points we're out to make). This section represents the bulk of the text, which tells you something about the focus of the book. It is composed of the following parts:

Part I

We begin with a general overview of Python, that answers commonly asked initial questions—why people use the language, what it's useful for, and so on. The first chapter introduces the major ideas underlying the technology, to give you some background context.

This part then begins the technical material of the book, by exploring the ways that both you and Python run programs. Its goal is to give you just enough information to be able to work along with later examples and exercises. If you need more help getting started, additional configuration details are available in Appendix A.

Part II

Next, we begin our tour of the Python language, by studying Python's major built-in object types in depth: numbers, lists, dictionaries, and so on. You can get a lot done in Python with these tools alone.

Part III

The next part moves on to introduce Python's statements—the code you type to create and process objects in Python. It also presents Python's general syntax model.

Part IV

This part begins our look at Python's higher-level program structure tools. Functions turn out to be a simple way to package code for reuse.

Part V

Python modules let you organize statements and functions into larger components, and this part illustrates how to create, use, and reload modules.

Part VI

Here we explore Python's object-oriented programming (OOP) tool, the class. As you'll see, OOP in Python is mostly about looking up names in linked objects.

Part VII

We wrap up the core language coverage of this book section with a look at Python's exception handling model and statements, and a brief overview of development tools. This comes last, because exceptions can be classes if you want them to be.

Outer Layers

Part VIII samples Python's built-in tools, and puts them to use in a collection of small example programs. Common tasks are demonstrated in Python to give you some real-world context, using both the language itself, and its standard libraries and tools.

Chapter 27

This chapter presents a selection of the modules and functions that are included in the default Python installation. By definition, they comprise the minimum set of modules you can reasonably expect any Python user to have access to. Knowing the contents of this standard toolset will likely save you weeks of work.

Chapter 28

This chapter presents a few real applications. By building on the language core explained in earlier parts and the built-in tools described in Chapter 27, we present many small but useful programs that show how to put it all together. We cover three areas that are of interest to most Python users: basic tasks, text processing, and system interfaces. We close with a brief discussion of Jython, the Java port of Python, and a substantial Jython program.

Chapter 29

This chapter discusses the layers of the Python community and specialized libraries that are either part of the standard Python distribution or freely available from third parties.

Appendixes

The book ends with appendixes that give platform-specific tips for using Python on various platforms (Appendix A), and provide solutions to exercises that appear at the end of the last chapter in each part (Appendix B). Note that the index and table of contents can be used to hunt for details, but there are no reference appendixes in this book. As mentioned earlier, the Python Pocket Reference, Second Edition (O'Reilly), as well as other books and the free Python reference manuals maintained at http://www.python.org, fill in syntax and built-in tool details.