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 =Falsewhile 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