shopping_cart = []
product_list = [
                [‘iphone‘,5800],
                [‘book‘,30],
                [‘茅台酒‘,650],
                [‘笔‘,5],
                [‘小米手机‘,2000],
]
salary = int(input(‘input you salary:‘))
while True:
    index = 0
    for product in product_list:
        print(index,product)
        index+=1
    choice = input(‘请输入商品编号，或者输入q退出：‘).strip()
    if choice.isdigit(): #判断输入是否为数字
        choice = int(choice)
        if choice >=0 and choice <= len(product_list): #商品存在
            product = product_list[choice]
            if product[1] <= salary: #买得起
                shopping_cart.append(product)
                salary-=product[1]
                print(‘Added product ‘+product[0]+‘ into shopping_cart ,your current balance:‘+str(salary))
            else:
                print(‘工资不够，商品的价格是‘+str(product[1])+‘你还差‘+str(product[1]-salary))
        else:
            print(‘商品不存在‘)
    elif choice==‘q‘:
            print(‘\033[31;1m------------已购买商品列表--------------\033[0m‘)
            for i in shopping_cart:
                print(i)
            print(‘您的余额为：‘,salary)
            print(‘\033[31;1m----------------end--------------------\033[0m‘)
            break
    else:
        print(‘无此选项‘)

menu = {
    ‘北京‘:{
        ‘海淀‘:{
            ‘五道口‘:{
                ‘soho‘:{},
                ‘网易‘:{},
                ‘google‘:{}
            },
            ‘中关村‘:{
                ‘爱奇艺‘:{},
                ‘汽车之家‘:{},
                ‘youku‘:{},
            },
            ‘上地‘:{
                ‘百度‘:{},
            },
        },
        ‘昌平‘:{
            ‘沙河‘:{
                ‘老男孩‘:{},
                ‘北航‘:{},
            },
            ‘天通苑‘:{},
            ‘回龙观‘:{},
        },
        ‘朝阳‘:{},
        ‘东城‘:{},
    },
    ‘上海‘:{
        ‘闵行‘:{
            "人民广场":{
                ‘炸鸡店‘:{}
            }
        },
        ‘闸北‘:{
            ‘火车战‘:{
                ‘携程‘:{}
            }
        },
        ‘浦东‘:{},
    },
    ‘山东‘:{},
}
break_flag=True
for k in menu.keys():
    print(k)      #打印第一级菜单
while break_flag:
    choice1 = input(‘请输入目的地：‘)   #输入第一级菜单
    if choice1 in menu.keys():           #输入字符在第一级菜单里
        for i in menu[choice1].keys():   #遍历第二级菜单
            print(i)                      #打印第二级菜单
        choice2 = input(‘请输入目的地：‘)    #输入第二级菜单
        if choice2 in menu[choice1].keys():   #输入字符在第二级菜单里
            for j in menu[choice1][choice2].keys():    #遍历第三级菜单
                print(j)                                #打印第三级菜单
            choice3 = input(‘请输入目的地：‘)      #输入第三级菜单
            if choice3 in menu[choice1][choice2].keys():          #输入字符在第三级菜单里
                for m in menu[choice1][choice2][choice3].keys():  #遍历第四级菜单
                    print(m)                                       #输出第四季菜单
                choice4 = input(‘请选择b返回，或者q直接退出‘)
                if choice4 ==‘q‘:
                    break_flag = False
                    break
                elif choice4==‘b‘:
                    break
                else:
                    print(‘请输入正确字符‘)
            elif choice3 == ‘q‘:
                break_flag = False
                break
            elif choice3 == ‘b‘:
                break
            else:
                print(‘请输入正确字符‘)
        elif choice2 == ‘q‘:
            break_flag = False
            break
        elif choice2 == ‘b‘:
            break
        else:
            print(‘请输入正确字符‘)
    elif choice1 == ‘q‘:
        break_flag = False
        break
    elif choice1 == ‘b‘:
        break
    else:
        print(‘请输入正确字符‘)