三级菜单

# -*- coding: utf-8 -*-
#__author__:Selid
#__date__:2018/12/13

menu_all={
    ‘甘肃省‘:{
        ‘兰州市‘:{
            ‘城关区‘:{},
            ‘七里河区‘:{},
            ‘安宁区‘:{},
            ‘西固区‘:{},
            ‘榆中县‘:{},
            ‘永登县‘:{}
        },
        ‘天水市‘:{
            ‘秦州区‘:{},
            ‘秦安县‘:{},
            ‘甘谷县‘:{},
            ‘武山县‘:{},
            ‘张家川县‘:{},
        },
        ‘武威市‘:{
            ‘古浪县‘:{},
            ‘凉州区‘:{},
            ‘民勤县‘:{},
            ‘天祝县‘:{},
        },
        ‘张掖市‘:{
            ‘甘州区‘:{},
            ‘高台县‘:{},
            ‘民乐县‘:{},
            ‘临泽县‘:{},
        },
    },
    ‘陕西省‘:{
        ‘西安市‘:{
            ‘新城区‘:{},
            ‘莲湖区‘:{},
            ‘莲湖区‘:{},
            ‘未央区‘:{},
            ‘雁塔区‘:{},
            ‘灞桥区‘:{},
            ‘阎良区‘:{},
            ‘阎良区‘:{},
            ‘长安区‘:{},
        },
        ‘宝鸡市‘:{
            ‘秦都区‘:{},
            ‘渭城区‘:{},
            ‘长武县‘:{},
            ‘淳化县‘:{},
            ‘旬邑县‘:{},
        },
        ‘铜川市‘:{
            ‘临渭区‘:{},
            ‘华州区‘:{},
            ‘大荔县‘:{},
            ‘合阳县‘:{},
        },
        ‘延安市‘:{
            ‘宝塔区‘:{},
            ‘按赛区‘:{},
            ‘延长线‘:{},
            ‘延川县‘:{},
        },

    }

}

parent_layers=[]
carrent_layer=menu_all

while True:
    for key in carrent_layer:
        print key
    choice=input(‘>>>‘).strip()
    if len(choice)==0:continue
    if choice in carrent_layer:
        parent_layers.append(carrent_layer)
        carrent_layer=carrent_layer[choice]
    elif choice==‘b‘:
        if parent_layers:
            carrent_layer=parent_layers.pop()
    else:print ‘无此项‘
else:
    print ‘programes exited‘