在两个字典中按索引对多个值求和[重复]

Question

我有两本字典

first_dict = {2020: [1000, 50], 2021: [2000, 10], 2024: [500, 5]}
second_dict = {2019: [500, 20], 2020: [2000, 30], 2021: [1000, 10]}

如何将具有相同键的第一个值和第二个值相加。生产：

resulting_dict = {2019: [500, 20], 2020: [3000, 80], 2021: [3000, 20], 2024: [500, 5]}

Answer 1

如果你确定所有列表的长度都是 2，你可以使用这个：

first_dict = {2020: [1000, 50], 2021: [2000, 10], 2024: [500, 5]}
second_dict = {2019: [500, 20], 2020: [2000, 30], 2021: [1000, 10]}

keys = set(first_dict).union(second_dict)    
res = {k: list(map(sum, zip(first_dict.get(k, [0, 0]), second_dict.get(k, [0, 0])))) for k in keys}
print(res)  # -> {2019: [500, 20], 2020: [3000, 80], 2021: [3000, 20], 2024: [500, 5]}

---

如果值列表的长度可以变化，我会使用zip_longest from itertools：

res = {k: list(map(sum, zip_longest(first_dict.get(k, [0]), 
                                    second_dict.get(k, [0]), 
                                    fillvalue=0))) for k in keys}