Python学习5，三级菜单实例

_author_ = "Happyboy"

data = {
   '北京':{
        "昌平":{
           "沙河":["Happyboy","test"],
           "天通苑":["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":{},
         "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1>>:")
    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 choice3 == "q":
                        exit_flag = True
            if choice2 == "b":
                break
            elif choice2 == "q":
                exit_flag = True