这里比较难以理解。所以尽量不要使用多个过滤条件的exclude，而是用Q表达式。
PS：官方文档的解释
For example, the following query would exclude blogs that contain both entries with “Lennon” in the headline and entries published in 2008:
https://docs.djangoproject.com/en/1.11/topics/db/queries/#lookups-that-span-relationships
这里比较难以理解。所以尽量不要使用多个过滤条件的exclude，而是用Q表达式。 PS：官方文档的解释 For example, the following query would exclude blogs that contain both entries with “Lennon” in the headline and entries published in 2008: https://docs.djangoproject.com/en/1.11/topics/db/queries/#lookups-that-span-relationships