code: def flatten_list(multiply_list):
      
      if isinstance(multiply_list, list):
          return [rv for l in multiply_list for rv in flatten_list(l)]
      else:
          return [multiply_list]
docs: 碾平 list::
  
          >>> a = [1, 2, [3, 4], [[5, 6], [7, 8]]]
          >>> flatten_list(a)
          [1, 2, 3, 4, 5, 6, 7, 8]
  
      :param multiply_list: 混淆的多层列表
      :return: 单层的 list