listparser is a Python library that parses subscription lists (also called reading lists) and returns all of the feeds, subscription lists, and "opportunity" URLs that it finds. It supports OPML, RDF+FOAF, and the iGoogle exported settings format.
RXPY is a pure-Python regular expression library, compatible with the re package. RXPY can be used as a test-bed for new matching algorithms, since the parser and compatibility components are reusable.