Python in a Nutshell, 2nd Edition

Chapter 24. Structured Text: XML

XML, the eXtensible Markup Language, has become very widespread over the last few years. Like SGML (mentioned in The sgmllib Module), XML is a metalanguage, a language to describe markup languages. On top of XML 1.0, the XML community (mostly within the World Wide Web Consortium [W3C]) has standardized many other technologies, such as schema languages, Namespaces, XPath, XLink, XPointer, and XSLT.

Industry consortia in many fields have defined industry-specific markup languages on top of XML to facilitate data exchange among applications in those fields. Such industry standards let applications exchange data even when the applications are coded in different languages and deployed on different platforms by different firms. XML, related technologies, and XML-based markup languages are the basis for inter-application, cross-language, cross-platform data interchange in modern applications.

Python has excellent support for XML. The standard Python library supplies the xml package, which lets you use fundamental XML technology quite simply. The third-party package PyXML (http://pyxml.sf.net) extends the standard library’s xml with validating parsers, richer DOM implementations, and advanced technologies such as XPath and XSLT. Downloading and installing PyXML upgrades Python’s own xml packages, so it can be a good idea to do so even if you don’t use PyXML-specific features.

On top of PyXML, you can choose to install yet another freely available third-party ...