def process_query_string(self):
        """Parse the query string into Python structures.

        (Core)
        """
        try:
            p = httputil.parse_query_string(
                self.query_string,
                encoding=self.query_string_encoding,
            )
        except UnicodeDecodeError:
            raise cherrypy.HTTPError(
                404,
                'The given query string could not be processed. Query '
                'strings for this resource must be encoded with %r.'
                % self.query_string_encoding,
            )

        self.params.update(p)
Parse the query string into Python structures.

        (Core)
        
cherrypy/_cprequest.py