元组及其操作 元组在很多地方与列表很像，都是有序的，都可以通过[]指定索引来获取元素，不过元组创建好之后就不可以变动。
names=('sheldon','penny','leonard')
print(names)
print(names[1]) # 切
print(names.count('penny')) # 统计
print(names.index('penny')) # 索引
# names[1]='潘妮' # 替换 不可以
# names.remove('penny') # 删 不可以
# names.append('潘妮') # 增 不可以
购物车实例 1.简单的购物车 存在的缺点一旦，商品号输错就好运行失败；
salary=int(input('salary:'))
names1=('Iphone','Bike','Book','Car')
names2=('2500','800','60','3000')
names3=[]
print('-------------------')
for i in names1:
num=names1.index(i )
price=names2[names1.index(i) ]
print(num,i,price)
print('-------------------')
_abc=input('你是否要购物：（add）or（other）')
while _abc=='add':
num2=int(input("The shopping num:"))
price2=int(names2[num2])
if salary>price2:
names3.append(names1[num2])
names3.append(names2[num2])
print('你刚刚购买了：',num2,names1[num2],names2[num2 ])
salary=salary-price2
print('-------------------')
for i in names1:
num = names1.index(i)
price = names2[names1.index(i)]
print(num, i, price)
print('-------------------')
_abc=input('你是否要继续购物：（add）or（other）')
else:
print("you money is not enougy")
break
print("你购买的商品：",names3)
print('你的余额：',salary)
2.完善后的程序
product_list=[
('Iphone',5800),
('Mac pro',9800),
('Bike',8000),
('Book',20),
('Car',3000),
('Food',200)
] # 嵌套类型
shopping_list=[]
salary=input('input you salary:')
if salary.isdigit():
salary=int(salary)
while True:
for index,item in enumerate (product_list): # 取出列表的下标
print(index,item)
use_choice=input("你要买什么：")
if use_choice.isdigit() :
use_choice =int(use_choice )
if use_choice >=0 and use_choice <len(product_list ):
P_item=product_list [use_choice ]
if P_item[1]<=salary :
shopping_list .append(P_item)
salary -=P_item[1]
print("Added %s into shopping car,you moneny is \033[31;1m%s\033[0m"%(P_item ,salary))
else:
print("\033[41;1m你的余额不足，只剩%s\033[0m"%(salary ))
else :
print("没有该类产品...")
elif use_choice =='q':
print("----------shopping list-----------")
for i in shopping_list :
print(i)
print('你的余额剩%s'%(salary))
# break
exit()
else:
print("invalid option")
