Learning Python - Mark Lutz [14]
This Book’s Style and Structure
This book is based on training materials developed for a three-day hands-on Python course. You’ll find quizzes at the end of each chapter, and exercises at the end of the last chapter of each part. Solutions to chapter quizzes appear in the chapters themselves, and solutions to part exercises show up in Appendix B. The quizzes are designed to review material, while the exercises are designed to get you coding right away and are usually one of the highlights of the course.
I strongly recommend working through the quizzes and exercises along the way, not only to gain Python programming experience, but also because some of the exercises raise issues not covered elsewhere in the book. The solutions in the chapters and in Appendix B should help you if you get stuck (and you are encouraged to peek at the answers as much and as often as you like).
The overall structure of this book is also derived from class materials. Because this text is designed to introduce language basics quickly, I’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 draw upon ideas introduced in earlier ones (e.g., by the time we get to classes, I’ll assume you know how to write functions), so a linear reading makes the most sense for most readers.
In general terms, this book presents the Python language in a linear 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 text artificial, but they illustrate the points it aims to make). More specifically, here is what you will find:
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. Then the technical material of the book begins, as we explore the ways that both we and Python run programs. The goal of this part of the book is to give you just enough information to be able to follow along with later examples and exercises.
Part II
Next, we begin our tour of the Python language, 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. This is the most substantial part of the book because we lay groundwork here for later chapters. We’ll also look at dynamic typing and its references—keys to using Python well—in this part.
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. Although this part focuses on syntax, it also introduces some related tools, such as the PyDoc system, and explores coding alternatives.
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 and avoid code redundancy. In this part, we will explore Python’s scoping rules, argument-passing techniques, and more.
Part V
Python modules let you organize statements and functions into larger components, and this part illustrates how to create, use, and reload modules. We’ll also look at some more advanced topics here, such as module packages, module reloading, and the __name__ variable.
Part VI
Here, we explore Python’s object-oriented programming tool, the class—an optional but powerful way to structure code for customization and reuse. As you’ll see, classes mostly reuse ideas