About the Programs in This Book

This book, and all the program examples in it, are based on Python Version 1.5. But since we'll stick to the core language here, you can be fairly sure that most of what we have to say won't change very much in later releases of Python.^[2] Most of this book applies to earlier Python versions too, except when it doesn't; naturally, if you try using extensions added after the release you've got, all bets are off. As a rule of thumb, the latest Python is the best Python. Because this book focuses on the core language, most of it also applies to JPython, the new Java-based Python implementation.

^[2] Well, probably. Judging from how Programming Python has stayed current over the last few years, the language itself changes very little over time, and when it does, it's still usually backward compatible with earlier releases (Guido adds things, but rarely changes things that are already there). Peripheral tools such as the Python/C API and the Tkinter GUI interface seem to be more prone to change, but we'll mostly ignore them here. Still, you should always check the release notes of later versions to see what's new.

Source code for the book's examples, as well as exercise solutions, can be fetched from O'Reilly's web site http://www.oreilly.com/catalog/lpython/.

So how do you run the examples? We'll get into start-up details in a few pages, but the first step is installing Python itself, unless it's already available on your machine. You can always fetch the latest and greatest Python release from http://www.python.org, Python's official web site. There, you'll find both prebuilt Python executables (which you just unpack and run) and the full source-code distribution (which you compile on your machine). You can also find Python on CD-ROMs, such as those sold by Walnut Creek, supplied with Linux distributions, or shipped with bigger Python books. Installation steps for both executable and source forms are well documented, so we won't say much more about this beyond a cursory overview in Chapter 1 (see Programming Python for install details).