Python实现购物车功能的方法分析


            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。

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希望本文所述对大家Python程序设计有所帮助。