三级菜单_要求：
1. 运行程序输出第一级菜单
2. 选择一级菜单某项，输出二级菜单，同理输出三级菜单
3. 菜单数据保存在文件中
4. 让用户选择是否要退出
5. 有返回上一级菜单的功能
完整代码：
#!/usr/bin/env python3
# Author:Robert
# --*-- coding: utf-8 --*--
data = {
"北京":{
"东城区":{
"安定门":["国子监大街","孔庙","钟楼"],
"建国门":["Jinbaojie","长安街","西街"],
"朝阳门":["东四南大街","朝阳门内大街","孚王府"]
},
"朝阳区":{
"和平街":["胜古庄社区","樱花社区","和平东街社区"],
"八里庄":["慈寿寺塔","定慧寺"],
"三里屯":["798艺术区","北京工人体育馆"]
},
"海淀":{}
},
'山东':{
"德州":{},
"青岛":{},
"济南":{}
},
'广东':{
"东莞":{},
"常熟":{},
"佛山":{}
}
}
exit_flag = False
while not exit_flag:
for i in data:
print(i)
choice = input("选择进入-->:")
if choice in data:
while not exit_flag:
for i2 in data[choice]:
print("\t",i2)
choice2 = input("选择进入2-->:")
if choice2 in data[choice]:
while not exit_flag:
for i3 in data[choice][choice2]:
print("\t\t",i3)
choice3 = input("选择进入3-->:")
if choice3 in data[choice][choice2]:
for i4 in data[choice][choice2][choice3]:
print("\t\t",i4)
choice4 = input("最后一层，按b返回-->:")
if choice4 == "b":
pass
elif choice4 == "q":
exit_flag = True
if choice3 == "b":
break
elif choice4 == "q":
exit_flag = True
if choice2 == "b":
break
elif choice4 == "q":
exit_flag = True
效果如下：
