python_三级字典

data = {
"北京":{
"昌平":{
"沙河":["oldboy","test"],
"天通苑":["链家地产","我爱我家"]
},
"朝阳":{
"望京":["奔驰","陌陌"],
"国贸":["CICC","HP"],
"东直门":["Advent","飞信"]
},
"海淀":{}
},
"山东":{
"德州":{"a":[1,2]},
"青岛":{"b":[3,4]},
"济南":{"c":[5,6]}
},
"广东":{
"东莞":{"d":[7,8]},
"常熟":{"e":[9,2]},
"佛山":{"f":[10,2]}
}

}
exit_flag = False
while not exit_flag:
for i in data: #第一层
print(i)

choice = input("选择进入>>>1：")

if choice in data:
while not exit_flag:
for i2 in data[choice]: #第二层
print(" ",i2)

choice2 = input("选择进入>>>2:")
if choice2 in data[choice]:
while not exit_flag:
for i3 in data[choice][choice2]: #第三层
print(" ",i3)

choice3 = input("选择进入>>>3:")
if choice3 in data[choice][choice2]:
for i4 in data[choice][choice2][choice3]: #第四层
print(" ",i4)
choice4 = input("最后一层，按b返回>>:")
if choice4 == 'b':
pass #pass什么也不做，为了让代码不出错，占位符
elif choice4 == 'q':
exit_flag =True
if choice3 == 'b':
break
elif choice3 == 'q':
exit_flag = True

if choice2 == 'b':
break
elif choice2 == 'q':
exit_flag = True