def __init__(self, path=None):
        """Initialize an HTTP Not Found error."""
        if path is None:
            request = cherrypy.serving.request
            path = request.script_name + request.path_info
        self.args = (path,)
        HTTPError.__init__(self, 404, "The path '%s' was not found." % path)
Initialize an HTTP Not Found error.
cherrypy/_cperror.py