Of the many successes of Python, this is the least known but one of the most impressive: it has gained the affection and the respect of a hard guy like Alex Martelli. That is not an easy task for a small, interpreted programming language like Python.
When I first met Alex Martelli, at Think3, he was one of the oldest and most experienced programmers of the company, a programmer who had already used most of the existing languages and had used these languages for the development of large and complex applications, the kind of projects that took months or years to complete. He knew Perl very, _very_ well and was used to rely on a robust, elegant and sophisticated language like C++ for the development of his applications (like Think3's Thinkdesign, a very complex 3D CAD program). He was writing a _lot_ of software, using a large array of different languages and tools. He was a well respected internal consultant at Think3, charged to solve difficult problems related to the software architecture of the program being developed. He was not an easy guy to impress with "yet another small language".
Despite this, Python has gained some room in his heart. I consider this fact as one of the most significant success of this elegant and powerfull language. To be completely honest, I'm not completely surprised by this ending.
Alex Martelli is the kind of scientist and professional that appreciate elegance, wherever he can see it. The taste for elegance, the ability to take pleasure in elegance, is an important part of the scientist and engineer personality. It is hard to be a really good software professional without having any kind of interest for elegance. When you need a simple tool that can face complex problems, you are asking for elegance. When you need a language that leave you with maintenable code, you are asking for elegance. When you want a single language for a wide array of applications, you are asking for elegance. Python can supply you with all the elegance you can ever ask for.
Alex's and David's book is a collection of good techniques that you can use to face a large set of problems with Python, from text transformation to GUI building to OpenGL grahics. You will not find here an introductory book, rather you will find a good second-reading book, the kind of book that can take you from the beginner level to the advanced. It is also the kind of book that can widen your knowledge of the Python world, showing you how this modern language can easily deal with problems that you usually face with C++ or the like.
If you are looking for an introductory book, buy "Learning Python" by Mark Lutz and David Ascher: it is the best one for this task. If you already know Python, buy this book and see how much you still do not know about it.