It’s been an exciting five years in the Python world. Since I wrote the first edition of this book between 1995 and 1996, Python has grown from a new kid on the scripting languages block to an established and widely used tool in companies around the world. Although measuring the popularity of an open source (http://opensource.org) and freely distributed tool such as Python is not always easy, most statistics available reveal exponential growth in Python’s popularity over the last five years. Among the most recent signs of Python’s explosive growth:
As I write this in 2001, there are now over a dozen Python books on the market, with almost that many more on the way (in 1995 there were none). Some of these books are focused on a particular domain (e.g., Windows), and some are available in German, French, and Japanese language editions.
In 1999, one leading industry observer suggested that there were as many as 300,000 Python users worldwide, based on various statistics. Other estimates are more optimistic still. In early 2000, for instance, the Python web site was already on track to service 500,000 new Python interpreter downloads by year end (in addition to other Python distribution mediums); this figure is likely closer to the true user-base size as I write this book.
Python is now regularly featured in industry publications. In fact, since 1995, Python creator Guido van Rossum has appeared on the cover of prominent tech magazines such as Linux Journal and Dr. Dobb’s Journal; the latter publication gave him a programming excellence award for Python.
Real companies have adopted Python for real products. It has shown up animating the latest Star Wars movie (Industrial Light & Magic), serving up maps and directories on the Internet (Yahoo), guiding users through Linux operating system installation (Red Hat), testing chips and boards (Intel), managing Internet discussion forums (Egroups), scripting online games (Origin), talking to CORBA frameworks (TCSI), implementing web site tools (Digital Creations’ Zope), scripting wireless products (Agilent), and much more.
User traffic on the main Python Internet newsgroup,
comp.lang.python, has risen dramatically too.
For instance, according to eGroups (see http://www.egroups.com/group/python-list),
there were 76 articles posted on that list in January 1994, and 2678
in January 2000 -- a 35-fold increase. Recent months have been
busier still (e.g., 4226 articles during June, 2000
alone -- roughly 140 per day), and growth has been constant since
the list’s inception. This, and all other user-base figures
cited in this preface, are likely to have increased by the time you
read this text. But even at current traffic rates, Python forums are
easily busy enough to consume the full-time attention of anyone with
full-time attention to burn.
There are now two annual Python conferences, one of which is hosted by O’Reilly & Associates. Attendance at Python conferences has roughly doubled in size every year. An annual Python Day is now also held in Europe.
Regional Python user groups have begun springing up in numerous sites in the U.S. and abroad, including Oregon, San Francisco, Washington D.C., Colorado, Italy, Korea, and England. Such groups work on Python-related enhancements, organize Python events, and more.
Python has grown to embrace both Microsoft Windows developers, with new support for COM and Active Scripting, as well as Java developers, with the new JPython (renamed “Jython”) Java-based implementation of the language. As we’ll see in this edition, the new COM support allows Python scripts to be both component server and client; Active Scripting allows Python code to be embedded in HTML web page code and run on either client or server; and JPython compiles Python scripts to Java Virtual Machine code so that they can be run in Java-aware systems and can seamlessly integrate Java class libraries for use by Python code. As an open source tool for simplifying web site construction, the Python-based Zope web application framework discussed in this edition has also begun capturing the attention of webmasters and CGI coders.
On the pragmatics front, commercial support, consulting, prepackaged distributions, and professional training for Python are now readily available from a variety of sources. For instance, the Python interpreter can be obtained on CDs and packages sold by various companies (including Walnut Creek, Dr. Dobb’s Journal, and ActiveState), and Python usually comes prebuilt and free with most Linux operating system distributions.
It’s now possible to make money as a Python programmer (without having to resort to writing large, seminal books). As I write this book, the Python job board at http://www.python.org/Jobs.html lists some 60 companies seeking Python programmers in the U.S. and abroad. Searches for Python at popular employment sites yield even more hits -- for instance, 285 Python-related jobs on Monster.com, and 369 on dice.com. Not that anyone should switch jobs, of course, but it’s nice to know that you can now make a living by applying a language that also happens to be a pleasure to use.
Python has also played host to numerous tools development efforts. Among the most prominent as I write these words: the Software Carpentry project, which is developing new core software tools in Python; ActiveState, which ison the verge of releasing a set of Windows and Linux-focused Python development products; and PythonWare, which is about to release an integrated Python development environment and GUI builder.
As I write this preface, ActiveState has also announced a new Python compiler for the Microsoft .NET framework and C# language environment -- a true Python compiler and independent implementation of the Python language that generates DLL and EXE files, allows Python code to be developed under Visual Studio, and provides seamless .NET integration for Python scripts. It promises to be a third implementation of Python, along with the standard C-based Python, and the JPython Java-based system.
Python has also begun attracting the attention of educators, many of whom see Python as a “Pascal of the 2000s” -- an ideal language for teaching programming, due to its simplicity and structure. Part of this appeal was spawned by Guido van Rossum’s proposed Computer Programming for Everybody (CP4E) project, aimed at making Python the language of choice for first-time programmers worldwide. At this writing the future of CP4E itself is uncertain, but a Python special interest group (SIG) has been formed to address education-related topics. Regardless of any particular initiative’s outcome, Python promises to make programming more accessible to the masses of people who will surely soon grow tired of clicking preprogrammed links, as they evolve from computer users to computer scripters.
In other words, it’s not 1995 anymore. Much of the preceding list was unimaginable when the first edition of this book was conceived. Naturally, this list is doomed to be out of date even before this book hits the shelves, but it is nonetheless representative of the sorts of milestones that have occurred over the last five years, and will continue to occur for years to come. As a language optimized to address the productivity demands of today’s software world, Python’s best is undoubtedly yet to come.
 As I was writing this book, Linux Journal also published a special Python supplement with their May 2000 edition -- the cover of which, of course, featured a naked man seated outdoors in front of a computer desk instead of a piano. If you don’t know why that is funny, you need to watch a few reruns from Python’s namesake, the Monty Python television series (consider it a first suggested exercise). I’ll say more about the implications of Python’s name in the first chapter.
 See http://www.python.org for more details. Some companies don’t disclose their Python use for competitive reasons, though many eventually become known when one of their web pages crashes and displays a Python error message in a browser. Hewlett Packard is generally counted among companies thus “outed.”