如何从字典中删除两个重复项？

Question

I'm writing a reducer for a MapReduce program that is supposed to read two csv files: all-bills.csv and open-bills.csv . What I want to do is remove values in open-bills from all bills so that I can get all the paid bills.

What I have done is to add all the entries into a dictionary in my reducer. How do I remove the entries that occur twice or more than that so that I'm left with just the paid bills in my dictionary?

Answer 1

尝试这个：

{k: v for k, v in all_bills.items() if k not in open_bills}