def previous_history(self,current): # (C-p)
        if self.history_cursor==len(self.history):
            self.history.append(current.copy()) #do not use add_history since we do not want to increment cursor
            
        if self.history_cursor > 0:
            self.history_cursor -= 1
            current.set_line(self.history[self.history_cursor].get_line_text())
            current.point=lineobj.EndOfLine
Move back through the history list, fetching the previous command.
dataset/ETHPy150Open deanhiller/databus/webapp/play1.3.x/python/Lib/site-packages/pyreadline/lineeditor/history.py/LineHistory.previous_history