分析：此题目考虑到了字典，元组等数据，用字典比较好实现一些。

难点一：可随时返回上一级

思考中

为了方便先做三个省，每个省2个市，每个市1个县

难点二：随时退出程序。

思考中。

 

china_city = {
    "河北":{
            "石家庄":{
                        "栾城","正定"
                    },
            "衡水":{
                    "枣强","武邑"
                    }
            },
    "黑龙江省":{
            "哈尔滨":{
                "五常","木兰"
                    },
            "佳木斯":{
                "同江","东风"
                    }
                 },
    "广西省":{
            "南宁":{
                "江南","马山"
                    },
            "玉林":{
                "玉州","兴业"
            }
    }
}

def city_print(sheng,shi):
    sheng_namber = 0
    sheng_key = list(china_city.keys())

    if sheng == 0 and shi == 0:
        for i in china_city.keys():
            print(i)
    elif sheng !=0 and shi ==0 :
        sheng_zhi = sheng_key[sheng-1]
        for i in china_city[sheng_zhi].keys():
            print(i)
        shiqu = int(input("请输入你要查询的市区编码》》》"))
        if shiqu>=1 and shiqu<3:
            shi_zhi = china_city[sheng_zhi]
            shi_key = list(shi_zhi.keys())
            print(shi_zhi[shi_key[shiqu -1]])
        else:
            print("看好在选择哦,请重新选择")
judge = True
while judge == True:
    print("欢迎使用全国城市遍历系统！".center(50,"*"))
    for i in china_city.keys():
        print(i)
    shengfen = int(input("请输入你要查询的省份编码》》》"))
    shiqu = 0
    city_print(shengfen,shiqu)
第一个版本

目前退出还没写

china_city = {
    "河北":{
            "石家庄":{
                        "栾城","正定"
                    },
            "衡水":{
                    "枣强","武邑"
                    }
            },
    "黑龙江省":{
            "哈尔滨":{
                "五常","木兰"
                    },
            "佳木斯":{
                "同江","东风"
                    }
                 },
    "广西省":{
            "南宁":{
                "江南","马山"
                    },
            "玉林":{
                "玉州","兴业"
            }
    }
}
def quits():
    import os
    print("感谢使用，再见！")
    os._exit(0)
def city_print(sheng,shi):
    sheng_namber = 0
    sheng_key = list(china_city.keys())

    if sheng == 0 and shi == 0:
        for i in china_city.keys():
            print(i)
    elif sheng !=0 and shi ==0 :
        sheng_zhi = sheng_key[sheng-1]
        for i in china_city[sheng_zhi].keys():
            print(i)
        shiqu = int(input("请输入你要查询的市区编码,退出请输入123》》》"))
        if shiqu>=1 and shiqu<3:
            shi_zhi = china_city[sheng_zhi]
            shi_key = list(shi_zhi.keys())
            print(shi_zhi[shi_key[shiqu -1]])
        elif shiqu == 123:
            quits()
        else:
            print("看好在选择哦,请重新选择")
judge = True
while judge == True:
    print("欢迎使用全国城市遍历系统！".center(50,"*"))
    for i in china_city.keys():
        print(i)
    shengfen = int(input("请输入你要查询的省份编码,退出请输入123》》》"))
    shiqu = 0
    if shengfen == 123:
        quits()
    city_print(shengfen,shiqu)

 

 

 

 1 china_city = {
 2     "河北":{
 3             "石家庄":{
 4                         "栾城","正定"
 5                     },
 6             "衡水":{
 7                     "枣强","武邑"
 8                     }
 9             },
10     "黑龙江省":{
11             "哈尔滨":{
12                 "五常","木兰"
13                     },
14             "佳木斯":{
15                 "同江","东风"
16                     }
17                  },
18     "广西省":{
19             "南宁":{
20                 "江南","马山"
21                     },
22             "玉林":{
23                 "玉州","兴业"
24             }
25     }
26 }
27 def quits():
28     import os
29     print("感谢使用，再见！")
30     os._exit(0)
31 current_layer = china_city #拿出字典
32 parent_layer = [] #保存所有父级，最后一个元素永远都是父级
33 while True:
34     for key in current_layer:
35         print(key)
36     choice = input(">>>").strip()
37     if len(choice) == 0:continue
38 
39     if choice in current_layer:
40         parent_layer.append(current_layer)#在进入下一层之前，把当前层（也就是下一层父级）
41         #下一层loop.当用户选择b的选择，就可以直接取列表的最后一个值出来就ok
42         current_layer = current_layer[choice]#改成了子层
43     elif choice == "b":
44         if parent_layer:
45             current_layer = parent_layer.pop()
46     elif choice == "q":
47         quits()
48     else:
49         print("无此项！")
老师讲的版本-不好理解哦