states.py 文件源码

def no_match(self, context, transitions):
        """
        Override `StateWS.no_match` to generate a system message.

        This code should never be run.
        """
        self.reporter.severe(
            'Internal error: no transition pattern match.  State: "%s"; '
            'transitions: %s; context: %s; current line: %r.'
            % (self.__class__.__name__, transitions, context,
               self.state_machine.line))
        return context, None, []