Python购物车的实现课程

需求：

1.用户输入工资收入

2.打印商品列表

3.用户选择商品，不断的加入购物车

4.检测用户余额，直接捐款，不足提示余额不足

5.允许主动退出，退出时，打印已购商品列表

重点方法：

打印列表下标的方法：

a=['alex','sys','root','admin']

>>> for index,i in enumerate(a):
...     print(index,i)

0 alex
1 sys
2 root
3 admin

#!/usr/bin/env python3
# -*-conding:utf-8-**
# __Author__:'liudong'
salary=input("Input your salary:")
if salary.isdigit():
    salary=int(salary)
else:
    exit("Invalid data type...")
welcom_msg='Welcome to Shopping mall'.center(50,'-')
print(welcom_msg)
exit_flag=False
product_list = [
    ('Iphone',5000),
    ('Mac Air',8000),
    ('Mac Pro',9000),
    ('XiaoMi',20),
    ('Coffe',30),
    ('Bike',800),
    ('Cloth',200)
]
shop_car = []
while not exit_flag:
    #for product_item in product_list:
    #    p_name,p_price = product_item  #可选的写法
    print("Products list".center(50,'-'))
    # for p_name,p_price in product_list:
        # print(p_name,p_price)         #由于此方法后面打印下标时，会变成2个无组，所以用下面的方法打印
    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():   #肯定是选商品
        user_choice = int(user_choice)
        if user_choice < len(product_list):
            p_item = product_list[user_choice]
            if p_item[1] <= salary: #买的起
                shop_car.append(p_item) #放入购物车
                salary -= p_item[1] #扣钱
                print('Added [%s] into your shop car,your current balance is 33[31;1m[%s]33[0m' %
                  (p_item,salary))   ＃字体加颜色
            else:
                print('Your balance is [%s],cannot afford this product..' %salary)
    else:
        if user_choice == 'q' or user_choice == 'quit':
            print('purchased products as blew:'.center(40,'*'))
            for item in shop_car:
                print(item)
            print('END'.center(40,'*'))
            print('Your balance is [%s]' %salary)
            print('bye.')
            exit_flag = True
        elif user_choice == 'c' or user_choice == 'check':
            print('purchased products as blew:'.center(40, '*'))
            for item in shop_car:
                print(item)
            print('Your balance is 33[41;1m[%s]33[0m' % salary) #背景加颜色

编程的思维还要加强。。。。。