I'm trying to find a good search engine tool for my site, it needs to be (in prefered order) python, php, or perl

It needs to do more than just index the meta keywords tag. I need to be able to restrict it to certain directories (i only want it to search my support documentation), Fully customized templating of the results, and a keyword ban list. eventually i *might* want to allow pdf searching..

anybody recommend? i've tried a few but had problems wiht them.

We are using INDEXU http://www.indexu.com for one of our portal. Its a $99 payment.

Maybe i'm confused, but I think that Indexu is a link database.
For a search engine try in Hotscripts (http://www.hotscripts.com) or in CGI Resources (http://www.cgi-resources.com) .
I hope this help you
Regards