A fully-functional program does what it is supposed to do and crashes gracefully when it doesn't. For this reason, error handling is a key component of any program that you write.
Up to now, we have used simple feeds that I knew did not vary much in format or type of content. The information was always in ASCII (American Standard Code for Information Interchange). This means that it was the most basic form of text and was usually only English. Even the feed for Der Spiegel was to the English version of Der Spiegel, not the German. There is a major problem with this approach that makes it unsuitable for the real world. Essentially: the program cannot cope with any variation. It is ill-suited for a world where things go wrong.
If you are just coming into the series, this is not the beginning. Rather, there are a few steps that lead to this tutorial. The beginning of the series is "Laying the Groundwork with HTML, CGI, and PHP" and you should start there if you know Python already.
If you do not know Python, you will want to work through one of the tutorials according to your level of computer knowledge; there are tutorials for absolute beginners, programming novices, and for those who already know at least one language.
Other tutorials in this series:
Part 1 | 2 | 3 | 4 | 5
Get the Code!