平时不会的题

列表的增加

l=[1,2,'d']
l[1]=['a',9,'p']
print(l)
#[1, ['a', 9, 'p'], 'd']
l[1:2]=['a',9,'p']
print(l)
#[1, 'a', 9, 'p', 'd']

购物车：

goods = [{"name": "电脑", "price": 1999},
         {"name": "鼠标", "price": 10},
         {"name": "游艇", "price": 20},
         {"name": "美女", "price": 998},]
shopping_car = []
flag = True
while flag:
    asset_total = input('请输入你的总资产：')
    if asset_total.isdigit():
        asset_total = int(asset_total)
        print('*****请选择以下商品*****')
        for index,i in enumerate(goods,1):
            print('	{0}	{1}	{2}'.format(index, i['name'], i['price']))
        print('************************')
        while True:
            goods_num = input('请选择您输入的商品序号(输入Q或者q为退出)：')
            if goods_num.isdigit():
                goods_num = int(goods_num)
                if goods_num > 0 and goods_num <= len(goods):
                    goods_price = goods[goods_num - 1]['price']
                    if asset_total >= goods_price:
                        asset_total = asset_total - goods_price
                        shopping_car.append(goods[goods_num - 1])
                        print('您已经成功购买%s,您的余额是%d' %(goods[goods_num - 1]['name'],asset_total))
                    else:print('您的余额不足')
                else:print('请输入正确的数字')
            elif goods_num.lower() == 'q':
                print('您已经购买了如下商品')
                for i in shopping_car:
                    print(i)
                print('您的余额为%s' %asset_total)
                flag = False
                break
            else:print("请输入数字")
    else:print('请输入正确的数字')

 三级菜单：

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': {},
}
def menu_3(menu):
    while True:
        for key in menu:
            print(key)
        choice=input('选择:')
        if choice == 'q' or choice == 'b':
            return choice
        elif choice in menu and menu_3(menu[choice]):
            borq = menu_3(menu[choice])
            if borq == 'q':
                return 'q'
menu_3(menu)