from random import randint,sample
#随机取数
# a = sample("ABCDEF",randint(5,6))
# print(a)
# b1 = {x:randint(1,4) for x in sample("ABCDEF",randint(3,6))}
# b2 = {x:randint(1,4) for x in sample("ABCDEF",randint(3,6))}
# b3 = {x:randint(1,4) for x in sample("ABCDEF",randint(3,6))}
# print(b1,b2,b3)
b1 = {'A': 4, 'D': 4, 'F': 4, 'B': 3}
b2 = {'A': 4, 'B': 3, 'C': 4, 'D': 3, 'F': 4, 'E': 4}
b3 = {'A': 1, 'B': 1, 'C': 1, 'D': 4, 'F': 4}#找出公共key方法一：
ret = []
for x in b1:if x in b2 and x in b3:ret.append(x)print(ret)#方法二通过集合方式找出交集
s1 = set(b1.keys())
s2 = set(b2.keys())
s3 = set(b3.keys())
info = s1 & s2 & s3
print(info)map(dict.keys,[s1,s2,s3])from functools import reduceprint(reduce(lambda a,b:a & b,map(dict.keys,[b1,b2,b3])))

from collections import OrderedDict
dict1 = OrderedDict()dict1["1"] = 1
dict1["2"] = 2
dict1["3"] = 3
dict1["4"] = 4
print(dict1)
for k,v in dict1.items():print(k,v)

result：

OrderedDict([('1', 1), ('2', 2), ('3', 3), ('4', 4)])
1 1
2 2
3 3
4 4

from collections import deque
s = deque([],4)
while True:d = input("请输入数字")if d.isdigit():print("输入的是数字")s.append(d)elif d == "history":print(s)else:break

result：

请输入数字5
输入的是数字
请输入数字6
输入的是数字
请输入数字7
输入的是数字
请输入数字8
输入的是数字
请输入数字history
deque(['5', '6', '7', '8'], maxlen=4)
请输入数字100
输入的是数字
请输入数字history
deque(['6', '7', '8', '100'], maxlen=4)
请输入数字