简陋三级交互

#conding:utf-8

# 选做题：用户交互，显示省市县三级联动的选择
#
dic = {
    "河北": {
        "石家庄": ["鹿泉", "藁城", "元氏"],
        "邯郸": ["永年", "涉县", "磁县"],
    },
    "河南": {
        "信阳": ["光山", "固始", "新县"],
        "南阳": ["内乡", "社旗", "镇平"],
    },
    "山西": {
        "运城": ["万泉", "荣河", "临晋", "猗氏"],
        "太原": ["清徐", "阳曲", "娄烦"],
    },

}
print("默认不输入自动退出上一层")
tag = True
while tag:
    print( ‘\n‘"请选择省份:")
    for i in dic:
        print(i,end=‘ ‘)
    a = input(‘\n‘"开始你的表演：")
    if a in dic.keys():
        while tag:
            for j in dic[a]:
                print(j,end=‘ ‘)
            b = input(‘\n‘"请选择市：")
            if b in dic[a].keys():
                while tag:
                    for k in dic[a][b]:
                        print(k,end=‘ ‘)
                    c = input(‘\n‘"请选择县：")
                    if c in dic[a][b]:
                        print("已经选择：",c)
                        tag = False
                    elif len(c) == 0:
                        break
                    elif c not in dic[a][b]:
                        print("找不到这个县")

            elif len(b) == 0:
                break
            elif b not in dic[a].keys():
                print("找不到这个市")

    elif len(a) == 0:
        tag = False
    elif a not in dic.keys():
        print("找不到这个省份")