前几天由于过敏躺尸了两周，感觉都快废了。想要再次跨考计算机的计划遭到了家人的激烈反对。最后不了了之，对本行业越来越失望，希望通过这三年的自学成功跳行。
这次作业多学了好多东西才做出来深感码力不足，if-else循环用的太多了。即便刚学了函数，还是不知道使用函数精简代码的套路。希望后续课程有作补充。
作业要求
一、购物模式：
1.顾客输入薪水后打印商品列表
2.顾客可以根据商品列表的下标购买商品
3.若薪水不足支付购买的商品会报错
4.顾客退出的时候打印购买的商品列表并显示余额退出
二、管理员模式
1.在输入薪水的时候输入:administrator即可进入管理员模式
2.可根据商品的编号修改商品名称、价格
3.可添加新的商品
4.最后把修改后的商品数据写入商品文本中
前期准备工作
在源码同一文件夹下创建一商品文本内容如下：
源代码
1 #author : negu
2 # -*- coding: utf-8 -*-
3 def list_loop(list):#展示商品列表的函数
4 for index,i in enumerate(list):#把每项的下标取出来
5 if index == 0:
6 continue
7 print(index,i)
8 view_list = ['blank']#商品列表，第一项占位，让商品序号从1开始。
9 with open('goods','r+',encoding='utf-8') as f:#如上一次作业一样，把文件导入列表
10 for line in f:
11 goodname = line.strip().split(':')[0]
12 goodprice = line.strip().split(':')[1]
13 view_list.append([goodname,goodprice])#以子列表形式导入列表
14 salary = input("please input your salary:\t")
15 if salary == 'administrator':#进入管理员模式
16 while True:
17 list_loop(view_list)
18 choose = input("1.change the item name,2.chage the item price,3.add new item,else:quit:\t")
19 if choose == '1':
20 choose_1 = input("which item's name do you want to chage?:\t")#想改名字的商品的编号
21 if choose_1.isdigit():
22 choose_1 = int(choose_1)
23 if choose_1 <= len(view_list) and choose_1 >= 0 :#判断是否在列表中，重复代码下次多次出现
24 p_1 = view_list[choose_1]
25 choose_1_1 = input('input its new name:\t')#新名字
26 p_1[0] = choose_1_1
27 else :
28 print('invalid number')
29 continue
30 else :
31 print('invalid number')
32 continue
33 elif choose == '2':
34 choose_2 = input("which item's price do you want to change?:\t")#想改价格的商品的编号
35 if choose_2.isdigit():
36 choose_2 = int(choose_2)
37 if choose_2 <= len(view_list) and choose_2 >= 0 :
38 p_1 = view_list[choose_2]
39 choose_2_2 = input('input its new price:\t')#新价格
40 else:
41 print('invalid number')
42 continue
43 else:
44 print('invalid number')
45 continue
46 p_1[1] = choose_2_2
47 elif choose == '3':#添加新商品
48 temporary_name = input("input your good's name:\t")
49 temporary_price = input("input your good's price:\t")
50 if temporary_price.isdigit():
51 pass
52 else:
53 print('invalid number')
54 continue
55 view_list.append([temporary_name,temporary_price])#临时列表追加新商品
56 elif choose == 'q':
57 with open('goods','w+',encoding='utf-8') as fi :
58 for i in view_list:
59 if i == 'blank':
60 continue
61 s = '%s:%s\n'%(i[0],i[1])
62 fi.write(s)#将临时列表的商品写入文本中
63 exit()
64 else :
65 print('invalid number')
66 continue
67 elif salary.isdigit():
68 salary = int(salary)
69 elif not salary.isdigit():
70 print('invalid input')
71 exit()
72 cart = []
73 while True :
74 for index,i in enumerate(view_list):#把每项的下标取出来
75 if index == 0:
76 continue
77 print(index,i)
78 serial_number = input(" please input item number:\t")
79 if serial_number.isdigit():
80 serial_number = int(serial_number)
81 if serial_number <= len(view_list) and serial_number >= 0 :
82 p_i = view_list[serial_number]
83 if p_i[1].isdigit():
84 p_i[1] = int(p_i[1])
85 if p_i[1] <= salary: #买得起
86 cart.append(p_i[0])
87 salary -= p_i[1]
88 print("added %s into shopping cart,your current balance is %s"%(p_i,salary))
89 else : print("\033[41;1myour current balance is not enough.\033[0m")
90 #len函数返回的是列表的长度
91 else:
92 print("商品不存在")
93 elif serial_number == 'q' :
94 print("您已购买的产品有:",cart)
95 exit()
96 else:
97 print("invalid input")
98 continue
测试方法
一、管理员模式 1.进入管理员模式将banana改成watermelon，价格改成25.
2.加一个新的商品pear，价格8
二、顾客模式
1.输入2000薪水随便买些东西
2.输入20薪水买爆报错
3.输入'fuck off'看一下系统的识别能力
结果
一、
1.输出结果：
please input your salary: administrator 1 ['banana', '10'] 2 ['flowers', '30'] 3 ['bottle', '15'] 4 ['flag', '11'] 1.change the item name,2.chage the item price,3.add new item,else:quit: 1 which item's name do you want to chage?: 1 input its new name: watermelon 1 ['watermelon', '10'] 2 ['flowers', '30'] 3 ['bottle', '15'] 4 ['flag', '11'] 1.change the item name,2.chage the item price,3.add new item,else:quit: 2 which item's price do you want to change?: 1 input its new price: 25 1 ['watermelon', '25'] 2 ['flowers', '30'] 3 ['bottle', '15'] 4 ['flag', '11'] 1.change the item name,2.chage the item price,3.add new item,else:quit: 3 input your good's name: pear input your good's price: 8 1 ['watermelon', '25'] 2 ['flowers', '30'] 3 ['bottle', '15'] 4 ['flag', '11'] 5 ['pear', '8'] 1.change the item name,2.chage the item price,3.add new item,else:quit: q Process finished with exit code 0
2.商品文本图：
二、
1.正常买东西输出结果：
please input your salary: 2000 1 ['watermelon', '25'] 2 ['flowers', '30'] 3 ['bottle', '15'] 4 ['flag', '11'] 5 ['pear', '8'] please input item number: 1 added ['watermelon', 25] into shopping cart,your current balance is 1975 1 ['watermelon', 25] 2 ['flowers', '30'] 3 ['bottle', '15'] 4 ['flag', '11'] 5 ['pear', '8'] please input item number: 2 added ['flowers', 30] into shopping cart,your current balance is 1945 1 ['watermelon', 25] 2 ['flowers', 30] 3 ['bottle', '15'] 4 ['flag', '11'] 5 ['pear', '8'] please input item number: 3 added ['bottle', 15] into shopping cart,your current balance is 1930 1 ['watermelon', 25] 2 ['flowers', 30] 3 ['bottle', 15] 4 ['flag', '11'] 5 ['pear', '8'] please input item number: q 您已购买的产品有: ['watermelon', 'flowers', 'bottle']
2.买爆输出结果：
please input your salary: 20 1 ['watermelon', '25'] 2 ['flowers', '30'] 3 ['bottle', '15'] 4 ['flag', '11'] 5 ['pear', '8'] please input item number: 1 your current balance is not enough. 1 ['watermelon', 25] 2 ['flowers', '30'] 3 ['bottle', '15'] 4 ['flag', '11'] 5 ['pear', '8'] please input item number:
3.乱输东西的输出结果：
please input your salary: 2000 1 ['watermelon', '25'] 2 ['flowers', '30'] 3 ['bottle', '15'] 4 ['flag', '11'] 5 ['pear', '8'] please input item number: fuck off invalid input 1 ['watermelon', '25'] 2 ['flowers', '30'] 3 ['bottle', '15'] 4 ['flag', '11'] 5 ['pear', '8'] please input item number: