More ways than you can shake a stick at, but nowadays you should consider using WSGI if you want your code to be portable across many frameworks. The Web SIG worked very hard last year on defining this gateway interface, with the intention that it should become widely available, and implementations are available now on environments as diverse as mod_python and CherryPy.
You can read about it in Philip Eby's excellent PEP at
http://www.python.org/peps/pep-0333.html
WSGI isn't really something an application programmer can use; or at least it's not likely to be a very satisfying experience if they do. I'm optimistic that at some point most of the actively developed Python web frameworks we have now will be ported to WSGI. Ultimately, I think WSGI should be something a more casual Python web programmer wouldn't even realize exists.
-- Ian Bicking / [EMAIL PROTECTED] / http://blog.ianbicking.org -- http://mail.python.org/mailman/listinfo/python-list
