3.20---购物车练习
编写ATM程序实现下述功能，数据来源于文件db.txt
0、注册功能：用户输入账号名、密码、金额，按照固定的格式存入文件db.txt
1、登录功能：用户名不存在，要求必须先注册，用户名存在&输错三次锁定，登录成功后记录下登录状态（提示：可以使用全局变量来记录）
下述操作，要求登录后才能操作
1、充值功能：用户输入充值钱数，db.txt中该账号钱数完成修改
2、转账功能：用户A向用户B转账1000元，db.txt中完成用户A账号减钱，用户B账号加钱
3、提现功能：用户输入提现金额，db.txt中该账号钱数减少
4、查询余额功能：输入账号查询余额
# 注册函数 def register(): tag = True while tag: username = input("请输入注册账号：") with open("db.txt",mode="a+t",encoding="utf-8") as f: f.seek(0,0) for line in f: name,pwd,account = line.strip().split(":") if name == username: print("该用户名已存在，请重新输入！") break else: while True: password1 = input("请设定密码：") password2 = input("请确认密码：") if password1 == password2: print(f"恭喜！用户<{username}>注册成功！") f.write(f"{username}:{password1}:0\n") tag = False break else: print("两次密码不同！请重新输入！") # 登录函数 def login(): import time import os count = {} while True: username = input("请输入账号（q:退出）：") if os.path.exists(f"{username}.locked.txt"): print("您的账号已被锁定！请5秒后继续输入！") time.sleep(5) os.remove(f"{username}.locked.txt") count[username] = 0 if username == "q" or username =="Q": break with open("db.txt",mode="r+t",encoding="utf-8") as f: for line in f: name,pwd,account = line.strip().split(":") if name == username: while True: password = input("请输入密码(r:重输账号)：") if pwd == password: print(f"尊敬的用户<{name}>,您已登录成功！") logined.append(name) break elif password == "r" or password == "R": break else: if username in count: count[username] += 1 if count[username] == 3: with open(f"{username}.locked.txt",mode="wt",encoding="utf-8") as f: f.write(str(time.time())) print("您的账号已被锁定！请5秒后继续输入！") time.sleep(5) os.remove(f"{username}.locked.txt") count[username] = 0 break else: count[username] = 1 print("密码错误，请重新输入！") break else: print("该账号不存在！请先注册！") # 查找函数 # 找到该用户在数据库中的行，并返回 # 若找不到，则返回None def search_name(user): with open("db.txt",mode="rt",encoding="utf-8") as f: for line in f: name,pwd,account = line.strip().split(":") if name == user: return line # 新行换旧行，替换函数 def change(old,new): import os with open("db.txt",mode="rt",encoding="utf-8") as f,\ open(".db.swap.txt",mode="wt",encoding="utf-8") as f1: for line in f: if line == old: f1.write(new) else: f1.write(line) os.remove("db.txt") os.rename(".db.swap.txt","db.txt") # 充值函数 def charge(): # 先找此时登录账号，若无登录账号，提示登录。 if not logined: print("请先登录！") return old = search_name(logined[0]) name, password, account = old.strip().split(":") account = float(account) while True: money = input("请输入充值金额：") if money.isdigit(): account += float(money) print(f"充值{money}元成功！您的账户当前余额为：{account}元") new = f"{name}:{password}:{account}\n" break else: print("请输入数字。") change(old,new) # 转账函数： def transfer(): if not logined: print("请先登录！") return old_1 = search_name(logined[0]) name1, password1, account1 = old_1.strip().split(":") account1 = float(account1) while True: apt_account = input("请输入转账账户：") if search_name(apt_account): old_2 = search_name(apt_account) name2,password2,account2 = old_2.strip().split(":") account2 = float(account2) money = input("请输入转账金额：") if money.isdigit(): account1 -= float(money) account2 += float(money) print(f"转账{money}元至账户<{name2}>成功！您的账户当前余额为：{account1}元") new_1 = f"{name1}:{password1}:{account1}\n" new_2 = f"{name2}:{password2}:{account2}\n" break else: print("请输入数字。") else: print("转账账户不存在，请确认后重输！") change(old_1, new_1) change(old_2, new_2) # 提现函数 def withdraw(): if not logined: print("请先登录！") return old = search_name(logined[0]) name, password, account = old.strip().split(":") account = float(account) while True: money = input("请输入提现金额：") if money.isdigit(): if float(money) <= account: account -= float(money) print(f"提现{money}元成功！您的账户当前余额为：{account}元") new = f"{name}:{password}:{account}\n" break else: print(f"余额不足，当前余额为：{account}元") else: print("请输入数字。") change(old, new) # 查询余额函数 def check_balance(): if not logined: print("请先登录！") return old = search_name(logined[0]) name, password, account = old.strip().split(":") print(f"当前余额为：{account}") # 退出登录函数 def user_quit(): if not logined: print("请先登录！") return logined.pop() # ATM机流程函数 def Atm(): while True: print(" ATM ".center(50,"-")) for key in func_dic: print(key,func_dic[key][0]) print(" END ".center(50,"-")) cmd = input("请输入指令：") if cmd.isdigit(): if cmd in func_dic: func_dic[cmd][1]() else: print("指令不存在！") else: print("请输入数字！") input("请按Enter键继续。") # 函数字典 func_dic = {"1":("充值",charge),"2":("转账",transfer),"3":("提现",withdraw),"4":("查询余额",check_balance), "5":("登录",login),"6":("注册",register),"0":("退出当前账号",user_quit),"q":("退出程序",exit)} # 全局变量，维护登录状态 logined = [] Atm()
