python3 三级菜单-基础版

# -*- coding:utf-8 -*-  
data = {
    "北京":{
        "东城区":{
            "安定门":["国子监","孔庙","钟楼"],
            "建国门":["金宝街","长安街","西街"],
            "朝阳门":["东四","新街口","孚王府"],
        },
        "朝阳区":{
            "和平街":["顾家庄","樱花社区","东街"],
            "八里屯":["慈寿寺","定慧寺","前门"],
            "三里屯":["夜店","工体","后海酒吧"],
        },
        "海淀":{
            "中关村":["海龙","鼎好","科贸"],
            "五道口":["清华","北大","人大"],
            "航天桥":["公主坟","古城","长安街"],
        },
    }
}

exit_flag =False

while not exit_flag:
    for i in data:
        print(i)

    choice = input("选择1")
    if choice in data:
        while not exit_flag:
            for i2 in  data[choice]:
                print("\t",i2)
            choice2 = input("选择2")
            if choice2 in data[choice]:
                while not exit_flag:
                    for i3 in data[choice][choice2]:
                        print("\t\t",i3)
                    choice3 = input("选择3")
                    if choice3 in data[choice][choice2]:
                        for i4 in data[choice][choice2][choice3]:
                            print("\t\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