Here is a regex inverter invRegex.py that parses simple regular expressions, and creates a generator structure to generate strings that match the regex.
Yapps (Yet Another Python Parser System) is an easy to use parser generator that is written in Python and generates Python code. There are several parser generator systems already available for Python, including PyLR, kjParsing, PyBison, and mcf.pars, but I had different goals for my parser. Yapps is simple, is easy to use, and produces human-readable parsers. It is not fast, powerful, or particularly flexible. Yapps is designed to be used when regular expressions are not enough and other parser systems are too much: situations where you may write your own recursive descent parser.
atropine is a screen-scraping library built on top of BeautifulSoup, which helps programmers make assertions about document structure while getting at the data they are interested in.
SimpleParse is a BSD-licensed Python package providing a simple parser generator for use with the mxTextTools text-tagging engine. SimpleParse allows you to generate tagging tables for use with the text-tagging engine directly from your EBNF grammar.