優化了上一個購物車程序：http://www.cnblogs.com/klvchen/p/8577269.html

#輸入工資
salary = input("Please input your salary: ")

#判斷工資是否為整數
if salary.isdigit():
    salary = int(salary)
else:
    exit("you must input digit")

#定義購物車
cart = []
#商品信息
msg = [["iphone6s", 5800], ["mac book", 9000], ["coffee", 32], ["bicycle", 1500]]

while
 
 True:
　　#展示商品信息
    for k, v in enumerate(msg, 1):
        print("%s 商品名稱: %s, 價格: %d" % (k, v[0], v[1]))
    choice = input("Please select the product number you need to purchase ! [q] to exit")
　　#退出
    if choice == ‘q‘:
        print("========== You have buy ==========")
        for l in cart:
            
 
print(l)
        exit()
　　#選擇商品
    if choice.isdigit():
        choice = int(choice)
        if 0 < choice <= len(msg):
　　　　　　　#判斷余額是否充足
            if salary >= msg[choice-1][1]:
                salary -= msg[choice-1][1]
                print("You have buy %s, money has %d" %(msg[choice-1][0], salary))
                cart.append(msg[choice
 
-1][0])
            else:
                print("You don‘t you enough money! money has %d" %salary )
        else:
            print("Please select right product number!")
    else:
        print("Please select right options")

運行結果如下：

程序還有很多可以優化的地方，以後有空再琢磨~

Python 練習：簡單的購物車(二)