删除两个字典中非公共的键和值

删除两个字典中非公共的键和值

需求：对比两个字典，找出公共元素，将非公共元素删除

dict1={}
dict2={}
res=[]
for i in dict1:
    if i not in dict2:
        print(i)
        del dict1[i]
        res.append(i)

结果：报错
RuntimeError: dictionary changed size during iteration
1
2
3
4
5
6
7
8
9
10
11

修改代码：

dict1={"1":1,"2":2,"3":3,"4":4}
dict2={"1":1,"2":2}

res=[]
for i in list(dict1):
    if i not in list(dict2):
        print(i)
        dict1.pop(i)
        res.append(i)
print(len(res))
print(dict1)
测试结果：
dict1={'1': 1, '2': 2}
1
2
3
4
5
6
7
8
9
10
11
12
13