XML

Many Python programmers consider working with XML to be a right royal pain. However, XML is extremely popular for a wide range of purposes. Python programs frequently have to interact with it; both as a consumer that needs to interpret XML data from another source, and as a producer that needs to create XML data for other programs or computers to parse.

Python includes three well-documented libraries for interacting with XML documents in its standard library. Two are based on traditional XML parsing techniques, while the third is a nice Pythonic interface.

The SAX (Simple API for XML) library is an event-driven system that calls specific functions when specific objects are encountered in the byte stream: opening and closing tags, attributes, and contents. It can be unwieldy to work with, but has the advantage of parsing XML documents "on the fly" without having to load the entire stream into memory. This is useful for huge documents.

The DOM (Document Object Model) library takes a different...