old_contents: # -*- coding: utf-8 -*-
  # @Author: theo-l
  # @Date:   2017-06-28 20:38:33
  # @Last Modified by:   theo-l
  # @Last Modified time: 2017-07-08 20:46:47
  
  from base_models import BaseModel
  
new_contents: # -*- coding: utf-8 -*-
  # @Author: theo-l
  # @Date:   2017-06-28 20:38:33
  # @Last Modified by:   theo-l
  # @Last Modified time: 2017-07-08 20:50:07
  
  from .base_models import BaseModel
  
subject: use relative import