parser recommendation

[Filipe Fernandes]

I have a project that uses a proprietary format and I've been using
regex to extract information from it.  I haven't hit any roadblocks
yet, but I'd like to use a parsing library rather than maintain my own
code base of complicated regex's.  I've been intrigued by the parsers
available in python, which may add some much needed flexibility.

I've briefly looked at PLY and pyparsing.  There are several others,
but too many to enumerate.  My understanding is that PLY (although
more difficult to use) has much more flexibility than pyparsing.  I'm
basically looking to make an informed choice.  Not just for this
project, but for the long haul.  I'm not afraid of using a difficult
(to use or learn) parser either if it buys me something like
portability (with other languages) or flexibility).

I've been to a few websites that enumerate the parsers, but not all
that very helpful when it came to comparisons...

http://nedbatchelder.com/text/python-parsers.html
http://www.python.org/community/sigs/retired/parser-sig/towards-standard/

I'm not looking to start a flame war... I'd just like some honest opinions.. ;)

thanks,
filipe