基础要求： 1、启动程序后，输入用户名密码后，让用户输入工资，然后打印商品列表 2、允许用户根据商品编号购买商品 3、用户选择商品后，检测余额是否够，够就直接扣款，不够就提醒 4、可随时退出，退出时，打印已购买商品和余额 5、在用户使用过程中， 关键输出，如余额，商品已加入购物车等消息，需高亮显示
扩展需求： 1、用户下一次登录后，输入用户名密码，直接回到上次的状态，即上次消费的余额什么的还是那些，再次登录可继续购买 2、允许查询之前的消费记录
goods = [
{"name": "电脑", "price": 1999},
{"name": "鼠标", "price": 10},
{"name": "游艇", "price": 20},
{"name": "美女", "price": 998},
]
name_user = {}
验证帐号密码
1 def con(Username, Pwd): 2 with open(‘file.user‘, ‘r‘, encoding=‘UTF-8‘) as f: 3 date = eval(f.read().strip()) 4 for i in date: 5 if Username == i and Pwd == date[i]: 6 return True 7 else: 8 return False
写购买记录
1 def write_shop_file(b): 2 with open(‘file.user‘, ‘r+‘, encoding=‘UTF-8‘) as f: 3 date = eval(f.read().strip()) 4 f.seek(0) 5 f.truncate() 6 date[‘shopcar‘]= b 7 f.write(str(date)) 8 f.flush()
写金额
1 def write_money_file(money): 2 with open(‘file.user‘, ‘r+‘, encoding=‘UTF-8‘) as f: 3 date = eval(f.read().strip()) 4 f.seek(0) 5 f.truncate() 6 date[‘money‘] = money 7 f.write(str(date)) 8 f.flush()
读历史购买记录
1 def read_shop_file(): 2 with open(‘file.user‘, ‘r‘, encoding=‘UTF-8‘) as f: 3 date = eval(f.read().strip()) 4 old = (date[‘shopcar‘]) 5 return old
读历史金额
1 def read_money_file(): 2 with open(‘file.user‘, ‘r‘, encoding=‘UTF-8‘) as f: 3 date = eval(f.read().strip()) 4 money = date[‘money‘] 5 return money
继续购买
1 def old_buy(): 2 money = read_money_file() 3 old_res = read_shop_file() 4 while True: 5 print(‘----------商品列表------------‘) 6 for index, i in enumerate(goods): 7 print(index, i[‘name‘], i[‘price‘]) 8 num = input(‘请问需要购买什么？输入商品编号,或者按Q退出:‘) 9 if num.isdigit(): 10 num = int(num) 11 if num >= 0 and num <=len(goods)-1 and money >= goods[num][‘price‘]: 12 old_res.append(goods[num]) 13 money -= goods[num][‘price‘] 14 print(‘你的金额还剩下:‘‘\033[1;31;m%s\033[0m‘ % money) 15 print(‘\033[1;31;m%s\033[0m‘ % ‘成功加入购物车‘) 16 elif num >= 0 and num <= len(goods)-1 and money < goods[num][‘price‘]: 17 print(‘\033[1;31;m%s\033[0m‘ % ‘余额不足‘) 18 else: 19 print(‘输入商品不存在,请重新输入‘) 20 elif num == ‘q‘ or num ==‘Q‘: 21 if len(old_res) > 0: 22 print(‘你的金额还剩下:‘‘\033[1;31;m%s\033[0m‘ % money) 23 print(‘你总购买商品如下:‘) 24 for index, i in enumerate(old_res): 25 print(‘\033[1;31;m‘, end=‘‘) 26 print(index, i[‘name‘], i[‘price‘]) 27 print(‘\033[0m‘, end=‘‘) 28 time.sleep(1) 29 print(‘欢迎下次光临‘) 30 write_shop_file(old_res) 31 write_money_file(money) 32 break 33 else: 34 print(‘输入有误，请重新输入‘) 35 continue
新购买
1 def new_buy(): 2 new_res = [] 3 money = int(input(‘请输入金额：‘)) 4 while True: 5 print(‘----------商品列表------------‘) 6 for index, i in enumerate(goods): 7 print(index, i[‘name‘], i[‘price‘]) 8 num = input(‘请问需要购买什么？输入商品编号,或者按Q退出:‘) 9 if num.isdigit(): 10 num = int(num) 11 if num >= 0 and num <=len(goods)-1 and money >= goods[num][‘price‘]: #判断输入是否在索引内 12 new_res.append(goods[num]) 13 money -= goods[num][‘price‘] #没购买一次，金额自减 14 print(‘你的金额还剩下:‘‘\033[1;31;m%s\033[0m‘ % money) 15 print(‘\033[1;31;m%s\033[0m‘ % ‘成功加入购物车‘) 16 elif num >= 0 and num <= len(goods)-1 and money < goods[num][‘price‘]: 17 print(‘\033[1;31;m%s\033[0m‘ % ‘余额不足‘) 18 else: 19 print(‘输入商品不存在,请重新输入‘) 20 elif num == ‘q‘ or num == ‘Q‘: 21 if len(new_res) > 0: 22 print(‘你的金额还剩下:‘‘\033[1;31;m%s\033[0m‘ % money) 23 print(‘你购买商品如下:‘) 24 for index, i in enumerate(new_res): 25 print(‘\033[1;31;m‘, end=‘‘) 26 print(index, i[‘name‘], i[‘price‘]) 27 print(‘\033[0m‘, end=‘‘) 28 time.sleep(1) 29 print(‘欢迎下次光临‘) 30 write_shop_file(new_res) 31 write_money_file(money) 32 break 33 else: 34 print(‘输入有误，请重新输入‘) 35 continue
登入
1 def login(): 2 # 写帐号密码,判断是否是第一次登入，是就创建 3 with open(‘file.user‘, ‘r+‘, encoding=‘UTF-8‘) as f: 4 date = f.read() 5 if not date: 6 print(‘这是您第一次登入，请创建你的帐号和密码‘) 7 while True: 8 username = input(‘请输入你要创建的帐号:‘).strip() 9 pwd = input(‘请输入你要创建的密码:‘).strip() 10 pwd2 = input(‘请再次输入你要创建的密码:‘).strip() 11 if pwd == pwd2: 12 print(‘创建成功‘) 13 time.sleep(0.5) 14 name_user[username] = pwd 15 name_user[‘money‘] = 0 16 name_user[‘shopcar‘] = [] 17 print(name_user) 18 f.write(str(name_user)) 19 f.flush() 20 break 21 else: 22 print(‘创建失败，密码输入2次不一致‘) 23 time.sleep(0.5) 24 continue 25 while True: 26 Username = input(‘请输入帐号:‘).strip() 27 Pwd = input(‘请输入密码:‘).strip() 28 if con(Username, Pwd): 29 print(‘登入成功‘) 30 time.sleep(0.5) 31 money = read_money_file() #用来判断是否是第一次登入，如果是第一次就跳过，直接输入金额 32 if money != 0: # 用-1来做标记 33 print(‘你的金额还剩下:‘‘\033[1;31;m%s\033[0m‘ % money) 34 print(‘你上次的购买记录是：‘) 35 old_res = read_shop_file() 36 for index, i in enumerate(old_res): 37 print(‘\033[1;31;m‘, end=‘‘) 38 print(index, i[‘name‘], i[‘price‘]) 39 print(‘\033[0m‘, end=‘‘) 40 flag = input(‘请问是否继续上次购买，输入Y或者N:‘).strip() 41 if flag == ‘Y‘ or flag == ‘y‘: 42 old_buy() 43 elif flag == ‘N‘ or flag == ‘n‘: 44 new_buy() 45 else: 46 new_buy() 47 return True 48 else: 49 print(‘帐号或者密码错误，请重新输入‘) 50 time.sleep(0.5) 51 continue
原文：https://www.cnblogs.com/zhengyiqun1992/p/10015402.html
