三级菜单

region_list={"河北省":{"石家庄":["新乐","新集","赵县"],"保定":["唐县","满城","涞源"]},
              "山西":{"太原":["小店区","杏花岭区"],"大同":["大同县","西花园"]}}

def the_menu():
    print("*" * 10 + "欢迎来到地区查询系统" + "*" * 10)
    for i in region_list:

        print(i)
    print("-"*40)
    while True:
        the_input=input("输入q：=返回上级，输入a：=退出，输入地区：=查看下级信息:")
        if the_input=="a":
            break
        elif the_input=="河北省":
            for k in region_list["河北省"]:
                print(k)
            while True:
                the__input = input("返回上级输入：q请输入地区名称：")
                if the__input=="保定":
                    for i in region_list["河北省"]["保定"]:
                        print(i)
                elif the__input=="石家庄":
                    for i in region_list["河北省"]["石家庄"]:
                        print(i)
                elif the__input=="q":
                    break
        elif the_input=="山西":
            for i in region_list["山西"]:
                print(i)
                while True:
                    the__input = input("请输入地区名称：")
                    if the__input == "太原":
                        for i in region_list["山西"]["太原"]:
                            print(i)
                    elif the__input == "大同":
                        for i in region_list["山西"]["大同"]:
                            print(i)
                    elif the__input == "q":
                        break

        else:
            break

the_menu()