如何基于 2 个列表创建新的字典列表，并添加具有相同键的两个字典列表的值

Question

我有两个字典列表：

list1 = [{"month": "Jan", "amount":1}, {"month": "Feb", "amount":4}]
list2 = [{"month": "Jan", "amount":2}, {"month": "Feb", "amount":4}]

如何创建具有相同键的新字典列表，并添加具有相同“月份”的每个字典的“金额”值？

target = [{"month": "Jan", "amount":3, {"month": "Feb", "amount": 8}]

Answer 1

这实现了我上面建议的内容：

from collections import defaultdict

list1 = [{"month": "Jan", "amount":1}, {"month": "Feb", "amount":4}]
list2 = [{"month": "Jan", "amount":2}, {"month": "Feb", "amount":4}]
months = defaultdict(int)
for l in (list1,list2):
    for d in l:
        months[d['month']] += d['amount']

print(months)
target = [{'month':k,'amount':v} for k,v in months.items()]
print(target)

输出：

defaultdict(<class 'int'>, {'Jan': 3, 'Feb': 8})
[{'month': 'Jan', 'amount': 3}, {'month': 'Feb', 'amount': 8}]