This column continues David's introduction to functional programming (FP) in Python. Enjoy this introduction to different paradigms of program problem-solving, where David demonstrates several intermediate and advanced FP concepts. An object is a piece of data with procedures attached to it... A closure is a procedure with a piece of data attached to it. In Part 1, my previous column on functional programming, I introduced some basic concepts of FP. This column will delve a little bit deeper into this quite rich conceptual realm. For much of our delving, Bryn Keller's "Xoltar Toolkit" will provide valuable assistance. Keller has collected many of the strengths of FP into a nice little module containing pure Python implementations of the techniques. In addition to the module functional , Xoltar Toolkit includes the lazy module, which supports structures that evaluate "only when needed." Many traditionally functional languages also have lazy evaluation, so between these components, the Xoltar Toolkit lets you do much of what you might find in a functional language like Haskell.

wxPython is a toolkit for creating cross platform graphical user interfaces (GUI) for the programming language Python. wxGlade is a GUI designer for wxPython.

The Qt toolkit is a widely-used cross-platform GUI toolkit, available for Windows, Linux, Mac OSX, and handheld platforms. QT has a well-structured, but flexible, object-oriented organization, clear documentation, and an intuitive API. In this article, David Mertz and Boudewijn Rempt look at the Qt library, with a focus on the PyQt bindings that let Python programmers access Qt functionality.All in all, choosing a GUI toolkit for your application can be a tricky matter. Programmers in Python, as in many languages, have a wide variety of GUI toolkits to choose from, and each toolkit comes with its own advantages and disadvantages. Some are faster than others, some smaller; some easier to install and some more cross-platform (more to the point, some support specific features that you need to address). And of course, the various libraries are accompanied by various licenses.

In this tutorial you will learn how to build a simple website using CherryPy, much like this very website you are visiting right now.