Python 基础

_作业要求

1. 运行程序输出第一级菜单

2. 选择一级菜单某项，输出二级菜单，同理输出三级菜单

3. 菜单数据保存在文件中

4. 让用户选择是否要退出

5. 有返回上一级菜单的功能

评分标准：

用多层嵌套while循环的方式完成作业2，85分

只用一层循环完成作业2，100分

知识点总结：

1. 打开文件读取 字典信息， 用eval 从 字符串 转到 dictionary --- 没有成功

2. while, for 循环的掌握。while true的放的位置

3. 可以用function 的方式定义每次菜单打开，但是存在bug，最终用了比较low的方式完成作业。

My Work: 

#!usr/bin/env python
# -*- coding:utf-8 -*-
# Author: Jane Yue
# Key points: Dictionary;

import sys

menu_dict = {
    "华南":{
        "广东":["广州市","佛山市","深圳市","东莞市"],
        "广西":["南宁市","柳州市","桂林市","北海市"],
        "海南":["海口市","三亚市","三沙市","儋州市"]},
    "华东":{
        "上海":{"浦东新区": ['陆家嘴', '张江科创园', '世纪公园'],
              "卢湾区": ['日月光商场','K11'],
              "徐汇区": ['港汇', '环贸ipam'],
              "长宁区": ['中山公园'],
              "普陀区": ['真如']},
        "安徽":["合肥市","芜湖市","淮南市","马鞍山市"],
        "江苏":["南京市","无锡市","徐州市","常州市","苏州市"]},
    "华北":{
        "北京":["东城区","西城区","朝阳区","丰台区","石景山区","海淀区"],
        "山西":["太原市","大同市","阳泉市","长治市"],
        "河北":["石家庄市","唐山市","秦皇岛市","邢台市"]},
    "华中":{
        "湖北":["武汉市","黄石市","十堰市","十堰市"],
        "河南":["郑州市","开封市","洛阳市","平顶山市"],
        "湖南":["长沙市","株洲市","衡阳市","邵阳市"]},
    "西南":{
        "重庆":["万州区","涪陵区","渝中区","大渡口区"],
        "四川":["成都市","自贡市","攀枝花市","德阳市"],
        "贵州":["贵阳市","六盘水市","遵义市","安顺市"],}
}

while True:
    for i in sorted(menu_dict):   # 打印第一层
        print(i)

    choice_1 = input('1. 请选择您要查询的区域 【q:退出】 >>> ')
    if choice_1 in menu_dict:
        while True:
            for j in menu_dict[choice_1]:   #打印第二层
                print('	',j)
            choice_2 = input('2. 请选择您要查询的区域 【q:退出; b:返回】 >>>')
            if choice_2 in menu_dict[choice_1]:

                while True:
                    for k in menu_dict[choice_1][choice_2]:
                        print('		', k)
                    choice_3 = input('3. 请选择您要查询的区域。 请选【q:退出; b:返回】 >>>')
                    if choice_3 in menu_dict[choice_1][choice_2]:
                        for l in menu_dict[choice_1][choice_2][choice_3]:
                            print('			', l)
                        choice_4 = input('4. 最后一层。 请选择【b:返回】或任意键退出')
                        if choice_4 == 'b':
                            continue
                        else:
                            sys.exit()

                    if choice_3 == "b":
                        break
                    else:
                        print('感谢阅览')
                        sys.exit()

            elif choice_2 =="b":
                break
            elif choice_2 == "q":
                print('感谢阅览')
                sys.exit()
            else:
                print('请输入正确选项')
                continue
    elif choice_1 == "q":
        print('感谢阅览')
        sys.exit()
    else:
        print('请输入正确选项')
        continue

_{SAMPLE 1} 

data = {
    '北京': {
        '海淀': {
            '五道口': {
                'soho': {},
                '网易': {},
                'Google': {},
            },
            '中关村': {
                '爱奇艺': {},
                '汽车之家': {},
                'youku': {},
            },
            '上地': {
                'baidu': {},
            },
        },
        '昌平': {
            '沙河': {
                'oldboy': {},
                '北航': {},
            },
            '天通苑': {},
            '回龙观': {},
        },
        '朝阳': {},
        '东城': {},
    },
    '上海': {
        "黄浦": {
            '人民广场': {
                '炸鸡店': {},
            },
        },
        '闸北': {
            '火车站': {
                '携程': {},
            },
        },
        '浦东': {},
    },
    '山东': {},
}

exit_flag = False

while not exit_flag:
    for i in data:
        print(i)   # 进入死循环

    choice = input("your option >>>:")
    if choice in data:
        while not exit_flag:
            for j in data[choice]:
                print("	", j)
            choice2 = input('your 2nd option >>>:')
            while not exit_flag:
                for k in data[choice][choice2]:
                    print('		', k)
                choice3 = input('your 3rd option >>>:')
                if choice3 in data[choice][choice2]:
                    for l in data[choice][choice2][choice3]:
                        print('		', l)
                    choice4 = input("final, please input b for exit")
                    if choice4 == 'b':
                        pass  # pass == 啥都不做，必须写否则报错。作为占位符
                    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