Python入门：购物车实例

product_list=[('iphone',5800),
              ('pro',120000),
              ('python book',120),
              ('Bike',800),
              ('coffe',39)
]  #定义商品列表

shopping_list=[]  #定义购物车
salary=input("your sally:") #输入薪水
if salary.isdigit(): #判断是否为数字
    salary=int(salary)
    while True:
        for index,item in enumerate(product_list): #enumerate 取下标和内容
            print(index,item)
        user_choice=input("please you choose product:") #输入商品编号
        if user_choice.isdigit():
            user_choice=int(user_choice)
            if user_choice<len(product_list) and user_choice>=0:
                p_item=product_list[user_choice]
                if salary>=p_item[1]:
                    shopping_list.append(p_item)
                    salary=salary-p_item[1]
                    print("added %s into shopping cart,your current balance is %s"%(p_item,salary))
                else:
                    print("你的余额只剩 %s ,不能买了" %salary)
            else:
                print("您选择的不存在")
        elif user_choice=="q": #输入q 退出循环
            print("-------------shopping list----------")
            for i in shopping_list: #遍历打印购物车
                print(i)
            exit()
        else:
            print("Invalid option")
else:
    print("your salary is wrong")