[mod_python] newbie filter won't work

I'm new to mod_python and to apache config.

I would like to setup a master security "trap" that intercepts all .py urls
and then  check for a cookie, and if it exists, I send it to the legacy
server which should respond with the user name.  Most of our web stuff is on
that legacy server and it has it's own security model that is outside my
responsibility.  If the cookie doesn't exist, I redirect to our standard
login page.

It doesn't look like I can use the Apache Basic authentication, since that
gives me the Apache login popup.  I tried input filter, but can't get it to
work.  Can anyone show what I'm doing wrong?  my setup is...

-----------httpd.conf---------------------------------
<Directory "/var/www/html/modpytest">
        AddHandler mod_python .py
        PythonHandler form
#       PythonHandler mod_python.publisher
        PythonInputFilter security SECURITY
        AddInputFilter SECURITY .py
        PythonDebug On
</Directory>


-------------form.py------------------------------
from mod_python import apache
from mod_python import Cookie
from mod_python import Session
import urllib2

def handler(req):
    apache.log_error('in handler')
    req.content_type = "text/plain"
    text = "basic handler works"
    text += '\ndir(req) = ' 				+ str( dir(req))
    text += '\nget_config returns %s' 		% req.get_config()
    text += '\nget_remote_host() returns %s' 	% req.get_remote_host()
    text += '\nreq.the_request %s' 			% req.the_request
    text += '\nreq.unparsed_uri %s' 		% req.unparsed_uri
    text += '\nreeq.uri %s' 				% req.uri
    text += '\nreq.args = ' 			+ str(req.args) +'
'+str(type(req.args))
    req.write(text)
    return apache.OK

------------------security.py-----------------------
from mod_python import apache

def inputfilter(filter):
    apache.log_error("inputfilter called")
    s = filter.read()
    while s:
        filter.write(s.upper())
        s = filter.read()
    if s is None:
        filter.close() 

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