从多个字典中提取相同的key

有时有多个字典，需要从中提取出这些字典中共有的key

#!/usr/bin/env python
#coding:utf-8
#@Author:Andy

from random import randint, sample
# select the same key from different dict
print("Generate 3 dif dict:")

d1 = {k:randint(1, 10) for k in sample(["小王","小段","小李","小周","小小"],randint(1,5))}
d2 = {k:randint(1, 10) for k in sample(["小王","小段","小李","小周","小小"],randint(1,5))}
d3 = {k:randint(1, 10) for k in sample(["小王","小段","小李","小周","小小"],randint(1,5))}
for _ in (d1, d2, d3):
	print(_)

print("method 1:")
res = []
for _ in d1:
	if _ in d2 and _ in d3:
		res.append(_)
print(res)

 

但是注意，如果出现 ：sample larger than population的错误提示：如下图：

那是因为，randint(x,y)是左右都包含的，如果元素就5个，却用了randin(1,6)，就可能超出边界。