def do_logout(self, from_page='..', **kwargs):
        """Logout.

        May raise redirect, or return True if request handled.
        """
        sess = cherrypy.session
        username = sess.get(self.session_key)
        sess[self.session_key] = None
        if username:
            cherrypy.serving.request.login = None
            self.on_logout(username)
        raise cherrypy.HTTPRedirect(from_page)
Logout.

        May raise redirect, or return True if request handled.
        
cherrypy/lib/cptools.py