Take a closer look at SimpleParse/mxTextTools <//www.python.org/pypi/SimpleParse/2.0.1a3> We have used these to parse log files of several 100 MB with simple and complex grammars up to 250+ productions. Highly recommended. /Jean Brouwers PS) For an introduction see also this story <http://www-128.ibm.com/developerworks/linux/library/l-simple.html>