本文实例讲述了Python实现购物车功能的方法。分享给大家供大家参考，具体如下：

1、程序的源代码如下：

salary = input("input your salary:")

if salary.isdigit:

salary = int(salary)

else:

exit("salary is not digit!!")

welcome_msg = "welcome to our shoping mall"

print(welcome_msg.center(50,"-"))

product_list = [

("Iphone",5888),

("Mac Air",8000),

("XiaoMi",19.9),

("coffee",30),

("Tesla",820000),

("Bike",700),

("Cloth",200)

]

shop_car = []

#推出标志位

exit_flag = 0

while exit_flag is not True:

print("product list :".center(50,"-"))

for item in enumerate(product_list):

index = item[0] #获得商品序号

p_name = item[1][0] #获得商品名称

p_price= item[1][1] #获得商品价格

print(index,p_name,p_price)

user_choice = input("[q=quit,c=check] what do you want to buy?:")

if user_choice.isdigit():

user_choice = int(user_choice)

if user_choice < len(product_list): #输入的商品序号要在范围之内

p_item = product_list[user_choice] #选择的商品

if p_item[1] <= salary: #买得起

shop_car.append(p_item) #放入购物车

salary -= p_item[1] #减钱

print("purchased products are:".center(40, "-"))

for item in shop_car:

print(item)

print("Your balance is [%s]" % salary)

else: #买不起

print("Your balance is [%s],cannot buy the product!"%salary)

else:

print("we do not have the product,please input again!")

elif user_choice == "q" or user_choice == "quit":

print("purchased products are:".center(40,"-"))

for item in shop_car:

print(item)

print("END ".center(40,"-"))

print("Your balance is [%s]"%salary)

exit_flag =True

elif user_choice == "c" or user_choice == "check":

print("purchased products are:".center(40, "-"))

for item in shop_car:

print(item)

print("Your balance is %d" % salary)

print("Check ".center(40, "-"))

else:

print("Incorrect input ,please input again!!")

2、程序运行结果

input your salary:10000

-----------welcome to our shoping mall------------

------------------product list :------------------

0 Iphone 5888

1 Mac Air 8000

2 XiaoMi 19.9

3 coffee 30

4 Tesla 820000

5 Bike 700

6 Cloth 200

[q=quit,c=check] what do you want to buy?:0

added [[("Iphone", 5888)]] into shop car ,yourcurrent balence is 4112

------------------product list :------------------

0 Iphone 5888

1 Mac Air 8000

2 XiaoMi 19.9

3 coffee 30

4 Tesla 820000

5 Bike 700

6 Cloth 200

[q=quit,c=check] what do you want to buy?:1

Your balance is [4112],cannot buy the product!

------------------product list :------------------

0 Iphone 5888

1 Mac Air 8000

2 XiaoMi 19.9

3 coffee 30

4 Tesla 820000

5 Bike 700

6 Cloth 200

[q=quit,c=check] what do you want to buy?:c

shop car list are [[("Iphone", 5888)]],your balance is 4112

------------------product list :------------------

0 Iphone 5888

1 Mac Air 8000

2 XiaoMi 19.9

3 coffee 30

4 Tesla 820000

5 Bike 700

6 Cloth 200

[q=quit,c=check] what do you want to buy?:4

Your balance is [4112],cannot buy the product!

------------------product list :------------------

0 Iphone 5888

1 Mac Air 8000

2 XiaoMi 19.9

3 coffee 30

4 Tesla 820000

5 Bike 700

6 Cloth 200

[q=quit,c=check] what do you want to buy?:q

--------purchased products are:---------

("Iphone", 5888)

------------------END ------------------

Your balance is [4112]

Process finished with exit code 0

3、学习到的知识点

（1）print("product list :".center(50,"-"))

>>> print("product list :".center(50,"-"))

------------------product list :------------------

（2）for item in enumerate(product_list):

>>> for item in enumerate(product_list):

print(item)

(0, ("Iphone", 5888))

(1, ("Mac Air", 8000))

(2, ("XiaoMi", 19.9))

(3, ("coffee", 30))

(4, ("Tesla", 820000))

(5, ("Bike", 700))

(6, ("Cloth", 200))

enumerate函数返回一个生成器对象：（index,item）的元组。

（3）这里使用了列表+元组的形式存储商品列表，而不是字典，因为字典是无序的，每次打印顺序都不一样，而且不能通过索引进行取值。

希望本文所述对大家Python程序设计有所帮助。