总结购物车小程序知识点

购物车小程序：

知识点：

1. input()函数，while循环， if...elseif...else语句，for循环

2. 字符串方法 .isdigit()和.center()

3. 枚举 enumerate()

4. 列表切片与列表方法追加.append()

5. 词典的使用

6. 字符串格式化输出

#! /usr/bin/env python3
# -*- coding:UTF-8 -*-
# Author：F.W


salary = input("input your salary:")
if salary.isdigit():
    salary = int(salary) 输入的字符串如果是数字，强制转换为整型，方便后续比较大小
else:
    exit("invalid data type!") 输入如果不符合要求，提示退出程序
Welcome_msg = "Welcome to FAN shopping mall".center(50, '-')
print(Welcome_msg)

exit_flag = False
Product_List = [('iphone', 5000), ('bike', 700), ('cloth', 300), ('basketball', 150)]
Shopping_car = []
while not exit_flag:
    print('Product_List'.center(50, '-'))
    for item in enumerate(Product_List):
        index = item[0] 切片获得商品序号
        P_Name = item[1][0] 切片获得商品名称
        P_Price = item[1][1] 切片获得商品价格
        print(index, '.', P_Name, P_Price) 统一打印商品清单的输出次序
    User_Choice = input("What do you wanna buy? choose commodity's index or 'q'/'c' to do next(Note: q=quick,c=check)")
    if User_Choice.isdigit():
        User_Choice = int(User_Choice)
        if User_Choice < len(Product_List): 用户选择在商品数量范围内
            P_item = Product_List[User_Choice]
            if P_item[1] <= salary: 购买能力的衡量 商品价格与薪资的对比
                Shopping_car.append(P_item) 将商品追加到购物车列表中
                salary -= P_item[1] 扣款
                print("Added %s to Shopping_car, Your current balance is \033[1;43;31m %s \033[0m" % (P_item, salary))
            else:
                print("you current balance is %s, cannot afford this commodity %s your wanted." % (salary, P_item))
        else: 如果选择超出范围，给予提醒！
            print("you selected number is out of range, please check the Product_list then enter current number!")
    else:
        if User_Choice == 'c': 用户选择-查看购买信息及薪资结余情况以便下一步选择
            print("Your purchased products as follows:".center(50, '-'))
            for item in enumerate(Shopping_car):
                print(item)
            print("End".center(50, '-'))
            print("your current balance is %s" % salary)
        elif User_Choice == 'q':用户选择-决定结束购物，打印商品信息和薪资余额情况
            print("Your purchased products as follows:".center(50, '-'))
            for item in enumerate(Shopping_car):
                print(item)
            print("End".center(50, '-'))
            print("your current balance is %s" % salary)
            print("Thanks for your shopping! Bye!")
            exit_flag = True 跳出while循环