Django列表视图:在所有项目中使用时差

I'm rather new to Class Based Views, so this is probably obvious, but any tips are appreciated. I want to display "time left" for each item on a list. That is if I have 10 objects, each should display in the template the number of days, hours, mn left until a deadline arrives. Here's my attempt:I'm rather new to Class Based Views, so this is