跟著老師的，教程 重新敲了一遍代碼

# Author:XF

data={
    "上海":{
        "浦東新區":{
            "金橋":{
                "愛法新城":{},
                "文峰廣場":{},
                "金橋電腦城":{}
            }
        },
        "楊浦區":{
            "五角場":{
                "PC大佬個人電腦":{},
                "頤高數碼":{}
            }
        }

    },
    "新疆":{
        "巴州":{
            "庫爾勒":{
                "塔裏木":{},
                "尉犁縣":{},
                "若羌":{}
            }
        },
        "生產建設兵團":{
            "農二師":{
                "32團":{},
                "33團":{}
            }
        }
    }
}

exit_flag=False

while not exit_flag:
    for s1 in data:
        print(s1)
    select1=input("請選擇:")
    if select1 in data:
        while not exit_flag:
            for s2 in data[select1]:
                print("\t", s2)
            select2 = input("請選擇:")
            if select2 in data[select1]:
                while not exit_flag:
                    for s3 in data[select1][select2]:
                        print("\t\t", s3)
                    select3 = input("請選擇:")
                    if select3 in data[select1][select2]:
                        for s4 in data[select1][select2][select3]:
                            print(s4)
                        select4 = input("程序已經到了最後一層")
                        if select4 == "b":
                            pass
                        if select4=="q":
                            exit_flag=True
                    if select3=="b":
                        break
                    if select3 == "q":
                        exit_flag = True
            if select2=="b":
                break
            if select2 == "q":
                exit_flag = True
    if select1 == "q":
        exit_flag = True

三級菜單小練習