python and xml   (link)

http://pyxml.sourceforge.net/topics/howto/node26.html
The xml.marshal package contains code for marshalling Python data types and objects into XML. The xml.marshal.generic module uses a simple DTD of its own, and provides Marshaller and Unmarshaller classes that can be subclassed to marshal objects using a different DTD.

http://diveintopython.org/xml_processing/
These next two chapters are about XML processing in Python. The following is a complete Python program which generates pseudo-random output based on a context-free grammar defined in an XML format.

http://feedparser.org/
Parse RSS and Atom feeds in Python. 2000 unit tests. Open source.

http://effbot.org/zone/element-index.htm
The Element type is a simple but flexible container object, designed to store hierarchical data structures, such as simplified XML infosets, in memory. The element type can be described as a cross between a Python list and a Python dictionary.

The Element type is available as a pure-Python implementation for Python 1.5.2 and later. A C implementation is also available, for use with CPython 2.1 and later. A Jython implementation will be included in a future release.