#作业二: 三级菜单 #要求: 打印省、市、县三级菜单 可返回上一级 可随时退出程序

oldhome={"河南":{'周口':{'鹿邑':{'涡北':{}}},'郑州':{'新郑':{'龙湖':{'双湖大道':{}}},'二七区':{'二七纪念塔':{}}}},'许昌':{'鄢陵':'未知领域'}}

over=True
while over:
    print("输入‘b’返回上一级，输入‘q’退出整个循环")
    for key in oldhome:
        print(key)
    floor1=input("第一楼:")
    if floor1=='b': #返回上一级
        break
    if floor1=='q':#退出整个循环
        over=False
        continue
    if floor1 not in oldhome:
        print("请输入现有的选项")
        continue
    while over:
        men1=oldhome[floor1]
        for key in men1:
            print(key)
        floor2 = input("第二楼：")
        if floor2 == 'b':
            break
        if floor2=='q':
            over=False
            continue
        if floor2 not in men1:
            print("请输入现有的选项")
            continue
        while over:
            men2=men1[floor2]
            for key in men2:
                print(key)
            floor3= input("第三楼:")
            if floor3 == 'b':
                break
            if floor3 == 'q':
                over=False
                continue
            if floor3 not in men2:
                print("请输入现有的选项")
                continue
            while over:
                men3=men2[floor3]
                for key in men3:
                    print(key)
                floor4 = input("第四楼：")
                if floor4=='b':
                    break
                if floor4=='q':
                    over=False
                    continue
                if floor4 not in men3:
                    print("请输入现有的选项")
                    continue