'''
购物小程序：
用户启动时先输入工资
用户启动程序后打印商品列表
允许用户选择购买商品
允许用户不断购买各种商品
购买时检测余额是否够，如果够直接扣款，否则打印余额不足
允许用户主动退出程序，退出时打印已购商品列表
'''
salary=input("input you salary:")
if salary.isdigit():
    salary=int(salary)
else:
    exit("invalid data type.....")
welcome_msg='welcome to Shopping mall'.center(50,'-')
print(welcome_msg)
product_list=[
    ('Iphone',5888),
    ('Mac Air',8000),
    ('Mac Pro',9000),
    ('XiaoMi',19.9),
    ('Coffee',30),
    ('Tesla',820000),
    ('Bike',900),
    ('cloth',200)
]
shop_car=[]
exit_flag=False
while not exit_flag:

    print('product list'.center(50, '-'))
    #for product_item in product_list:
        #p_name, p_price = product_item
    '''for p_name,p_price in product_list:
        print(p_name,p_price)'''
    for item in enumerate(product_list):
        index=item[0]
        p_name=item[1][0]
        p_price=item[1][1]
        print(index,p_name,p_price)
    user_choice=input("[q=quit,c=check]What do you want to buy?:")
    if user_choice.isdigit():#肯定是选择商品
        user_choice=int(user_choice)
        if user_choice<len(product_list):
            p_item=product_list[user_choice]
            if p_item[1]<salary:
                shop_car.append(p_item)#放入购物车
                salary -=p_item[1]#减钱
                print("Added [%s] into shop car,your current balance is [%s]"%(
                    p_item,salary))
            else:
                print("your balance is [%s],can not afford this.."%salary)
    else:
        if user_choice=='q' or user_choice=="quit":
            print("purchased products as belows:".center(40,'*'))
            for item in shop_car:
                print(item)
            print("End".center(40,'*'))
            print("your balance is [%s]"%salary)
            exit_flag=True
        elif user_choice=='c' or user_choice=="check":
            print("purchased products as belows:".center(40,'*'))
            for item in shop_car:
                print(item)
            print("End".center(40,'*'))
            print("your balance is [%s]"%salary)