products = [['phone1',100],['phone2',200],['phone3',300],['phone4',500],['phone5',500],['phone6',600]]
shopping_cart = []
run_flag = True #标志位

while run_flag:
    print("---------商品列表----------")
    for index, p in enumerate(products):
        print("%s.  %s  %s" % (index, p[0], p[1]))
    # choice = int(input("输入想购买的商品编号:"))   #input输入的都为字符串、所以要加上int
    choice = input("输入想购买的商品编号:")   #input输入的都为字符串、所以要加上int
    if choice.isdigit():
        choice = int(choice)
        if choice >= 0 and choice < len(products):
            shopping_cart.append(products[choice])
            print("Added product %s into shopping cart. " %(products[choice]))
        else:
            print("商品不存在")
    elif choice == 'q':
        if len(shopping_cart) >0:
            print("---------您购买的产品为-----------")
            for index, p in enumerate(shopping_cart):
                print("%s.  %s  %s" % (index, p[0], p[1]))
        # break
        run_flag  = False
    else:
        print("请输入数字")