python列表作业和购物车

'''
针对列表names=[‘金角大王’, ‘黑姑娘’, ‘rain’, ‘eva’, ‘狗蛋’, ‘银角大王’, ‘eva’,’鸡头’]进入以下操作


1.通过names.index()的方法返回第2个eva的索引值

2.把以上的列表通过切片的形式实现反转

3.打印列表中所有下标为奇数的值

4.通过names.index()方法找到第2个eva值 ，并将其改成EVA
'''
'''
names=['金角大王', '黑姑娘', 'rain', 'eva', '狗蛋', '银角大王', 'eva','鸡头']
#1.
# print(names.index('eva',names.index('eva')+1))
#2.
# names.reverse()
# print(names)
#3.
print(names[1::2])
#4.
names[6] = names[names.index('eva',names.index('eva')+1)].upper()
print(names)
'''

######################购物车######################
'''
实现功能要求：
1、启动程序后，让用户输入工资，然后进入循环，打印商品列表和编号
2、允许用户根据商品编号选择商品
3、用户选择商品后，检测余额是否够，够就直接扣款，并加入购物车， 不够就提醒余额不足
4、可随时退出，退出时，打印已购买商品和余额
'''

from collections import Counter

goods = [
{"name": "电脑", "price": 1999},
{"name": "鼠标", "price": 10},
{"name": "游艇", "price": 20},
{"name": "美女", "price": 9998},
]

# goods_new = {}
v1 = []
names=[] #商品的名字
price= []#商品的价格 1999 10 20 9998
for i in range(4):
    for v in goods[i].values():
        v1.append(v)
        # goods_new.setdefault("商品"+str(i),v1)    ??????????
        # print("商品{0:<13}号 {1:^15} ".format(i,v))
for i in v1[::2]:
    names.append(i)
for i in v1[1::2]:
    price.append(i)
#上面是构造商品数据
salary = int(input("input salary: "))#
print("商品列表".center(60,"*"))
print("{0:^15}{1:^32}{2:>8}(元)".format("num","name","price"))
for i in range(4):
    print("{0:^15}{1:^31}{2:^15}".format(i,names[i],price[i]))

#购买
buy_sign = False
buy_car = {}
while not buy_sign:
    try:
        choice =input('请输入要购买商品的编号，用逗号隔开：')
        num = [int(i) for i in choice.split(',') ]
        num =[i for i in num if i < 4]
        num_dic = dict(Counter(num))#把购买的商品序号包装成字典
        # num_dic = sorted(num_dic.items(),key=lambda dic:dic[0])#排序后转换成列表
        cost =0
        for k,v in num_dic.items():
            print("您选择了{0}号商品,{1}，数量是{2}，单价是{3}元".format(k,names[k],v,price[k]))
            buy_car.setdefault(names[k],"数量："+str(v))
            # print("buy_car: ",buy_car)
            cost += v * price[k]
        print("总价是：{}元,你的工资是：{}元".format(cost,salary))

        buy_choice = input("y或Y确认购买，q或Q退出: ")
        buy_choice = buy_choice.lower()
        if buy_choice == 'y' :
            if cost <= salary:
                print("购买成功，余额为{}元".format(salary-cost))
                for k, v in buy_car.items():
                    print("已经购买{0},{1}".format(k, v))
            else:
                print("工资不足，请重新选择")
                num_dic.clear()
                buy_car.clear()
        elif buy_choice == 'q':
            break
        else:
            print("输入错误")

        if num_dic:
            buy_sign =True
        # print(num_dic)
    except ValueError:
        print("输入错误，请重新输入.")
# print(num)