Learning Python - Mark Lutz [581]
You can also find Python on CD-ROMs supplied with Linux distributions, included with some products and computer systems, and enclosed with some other Python books. These tend to lag behind the current release somewhat, but usually not seriously so.
In addition, you can find Python in some free and commercial development bundles. For example, ActiveState distributes Python as part of its ActivePython, a package that combines standard Python with extensions for Windows development such as PyWin32, an IDE called PythonWin (described in Chapter 3), and other commonly used extensions. Python can also be had today in the Enthought Python Distribution—a package aimed at scientific computing needs—as well as in Portable Python, preconfigured to run directly from a portable device. Search the Web for details.
Finally, if you are interested in alternative Python implementations, run a web search to check out Jython (the Python port to the Java environment) and IronPython (Python for the C#/.NET world), both of which are described in Chapter 2. Installation of these systems is beyond the scope of this book.
Installation Steps
Once you’ve downloaded Python, you need to install it. Installation steps are very platform-specific, but here are a few pointers for the major Python platforms:
Windows
On Windows, Python comes as a self-installer MSI program file—simply double-click on its file icon, and answer Yes or Next at every prompt to perform a default install. The default install includes Python’s documentation set and support for tkinter (Tkinter in Python 2.6) GUIs, shelve databases, and the IDLE development GUI. Python 3.0 and 2.6 are normally installed in the directories C:\Python30 and C:\Python26, though this can be changed at install time.
For convenience, after the install Python shows up in the Start button’s All Programs menu. Python’s menu there has five entries that give quick access to common tasks: starting the IDLE user interface, reading module documentation, starting an interactive session, reading Python’s standard manuals in a web browser, and uninstalling. Most of these options involve concepts explored in detail elsewhere in this text.
When installed on Windows, Python also by default automatically registers itself to be the program that opens Python files when their icons are clicked (a program launch technique described in Chapter 3). It is also possible to build Python from its source code on Windows, but this is not commonly done.
One note for Windows Vista users: security features of the some versions of Vista change some of the rules for using MSI installer files. Although this may be a nonissue by the time you read these words, see the sidebar The Python MSI Installer on Windows Vista in this appendix for assistance if the current Python installer does not work, or does not place Python in the correct place on your machine.
Linux
On Linux, Python is available as one or more RPM files, which you unpack in the usual way (consult the RPM manpage for details). Depending on which RPMs you download, there may be one for Python itself, and another that adds support for tkinter GUIs and the IDLE environment. Because Linux is a Unix-like system, the next paragraph applies as well.
Unix
On Unix systems, Python is usually compiled from its full C source code distribution. This usually only requires you to unpack the file and run simple config and make commands; Python configures its own build procedure automatically, according to the system on which it is being compiled. However, be sure to see the package’s README file for more details on this process. Because Python is open source, its source code may be used and distributed free of charge.
On other platforms the installation details can differ widely, but they generally follow the platform’s normal conventions. Installing the “Pippy” port of Python for PalmOS, for example, requires a hotsync operation