def history_search_backward(self, e): # ()
        if self.previous_func and hasattr(self._history,self.previous_func.__name__):
            self._history.lastcommand=getattr(self._history,self.previous_func.__name__)
        else:
            self._history.lastcommand=None
        q=self._history.history_search_backward(self.l_buffer)
        self.l_buffer=q
        self.l_buffer.point=q.point
Search backward through the history for the string of characters
dataset/ETHPy150Open deanhiller/databus/webapp/play1.3.x/python/Lib/site-packages/pyreadline/modes/emacs.py/EmacsMode.history_search_backward