Small discussion and evaluation of different parsers.
["shlex"] (http://www.python.org/doc/current/lib/module-shlex.html)
["Plex"] (http://www.cosc.canterbury.ac.nz/~greg/python/Plex)
SimpleParse (http://members.rogers.com/mcfletch/programming/simpleparse/simpleparse.html)
["Spark"] (http://pages.cpsc.ucalgary.ca/~aycock/spark/)
["Yapps"] (http://theory.stanford.edu/~amitp/Yapps/)
["kwParsing"] (http://www.pythonpros.com/arw/kwParsing/kwParsing.html)
PyBison (http://www-db.stanford.edu/~hassan/Python/pybison.tar.gz)
["mcf.parse"] (http://starship.python.net/crew/mcfletch/)
["Trap"] (http://www.first.gmd.de/smile/trap/)
["PLY"] (http://systems.cs.uchicago.edu/ply/)
ToyParserGenerator (http://christophe.delord.free.fr/en/tpg/)
["TextUtils"] by Marc-André Lemburg ("mx") is not exactly a parser like we're used to, but it's a parser: http://www.lemburg.com/files/python/mxTextTools.html
Also see Python ParserSig @ http://www.python.org/sigs/parser-sig/ to discuss and select a standard parser generator for Python.
For some speed up one may use other parser generator systems and plug them in as modules.
For example:
["ANTLR"] (http://www.antlr.org/) C++ output (an older version with C output also available)