python入门之实例-购买商品

需求：

　　选择商品，结算所选的商品

#目前总资产

asset_all = 0

#所选商品总价

all_price = 0

#购物车列表，目前已选择商品

#每个元素的结构："商品名":{'price':"单个商品价格",'num':"购买数量"}

car_dict = {}

i1 = input("请输入总资产：")

asset_all += int(i1)

goods = [

    {"name":"电脑","price":1999},

    {"name":"鼠标","price":50},

    {"name":"键盘","price":40},

    {"name":"U盘","price":20}

]

#循环输出商品信息

for k,i in enumerate(goods,1):

    print(k,i['name'],i['price'])

#选择商品将其加入购物车

while True:

    i2 = input("请选择商品(q结算)：")

    if i2.lower() == 'q':

        break

    i2 -= 1

    name = goods[i2]["name"]

    price = goods[i2]["price"]

    if name in car_dict.keys():

        car_dict[name]["num"] += 1

    else:

        car_dict[name] = {"price":price,"num":1}

#计算购物车里所有商品的总价格

for i,j in car_dict.items():

    p = j["price"]

    n = j["num"]

    all_sum = p * n

    all_price += all_sum

#判断是否能购买商品

if all_price > asset_all:

    print("余额不足，请充值")

else:

    asset_all -= all_price

    print("购买成功")

    car_dict.clear()