code: def path_shift(self, shift=1):
          ''' Shift path fragments from PATH_INFO to SCRIPT_NAME and vice versa.
  
             :param shift: The number of path fragments to shift. May be negative
                           to change the shift direction. (default: 1)
          '''
          script_name = self.environ.get('SCRIPT_NAME','/')
          self['SCRIPT_NAME'], self.path = path_shift(script_name, self.path, shift)
          self['PATH_INFO'] = self.patf path_shift(self, shift=1):
          ''' Shift path fragments from PATH_INFO to SCRIPT_NAME and vice versa.
  
             :param shift: The number of path fragments to shift. May be negative
                           to change the shift direction. (default: 1)
          '''
          script_name = self.environ.get('SCRIPT_NAME','/')
          self['SCRIPT_NAME'], self.path = path_shift(script_name, self.path, shift)
          self['PATH_INFO'] = self.path
docs: Shift path fragments from PATH_INFO to SCRIPT_NAME and vice versa.
  
             :param shift: The number of path fragments to shift. May be negative
                           to change the shift direction. (default: 1)