Python模拟自动存取款机的查询、存取款、修改密码等操作

1.工作流程

2.模拟自动存取款机的操作

代码如下：

import msvcrt, sys, os#定义用星号隐藏密码输入的函数def psw_input():  li = []  while True:    ch = msvcrt.getch()    #回车    if ch == b'/r':      msvcrt.putch(b'/n')      break    #退格    elif ch == b'/x08':      if li:        li.pop()        msvcrt.putch(b'/b')        msvcrt.putch(b' ')        msvcrt.putch(b'/b')    #Esc    elif ch == b'/x1b':      break    else:      li.append(ch)      msvcrt.putch(b'*')  return li#定义CSDN银行ATM欢迎界面的函数def ATM():  '''  CSDN银行ATM欢迎界面的函数  '''  print("="*14,"Bank of CSDN","="*14,"/n")  print("{:^42}".format("ATM"),"/n")  print("="*14,"Bank of CSDN","="*14,"/n")#CSDN银行用户列表信息，用户信息包含：姓名、余额、密码（6位）、银行卡号（19位）user_list = [{"name":"张 三","balance":10000,"password":"000000","numbers":"0000000000000000000"},{"name":"李 四","balance":20000,"password":"111111","numbers":"1111111111111111111"},{"name":"王 五","balance":30000,"password":"222222","numbers":"2222222222222222222"}]#定义验证银行卡号与密码匹配的函数def check(user_name,user_password):  '''  验证银行卡号与密码匹配的函数  '''   for i in range(len(user_list)):    if user_name == user_list[i]["numbers"] and user_password == user_list[i]["password"]:      return i #银行卡号与密码匹配则返回该用户在ATM系统内的ID值，否则返回None值#定义用户登录成功后操作界面的函数def interface():  '''  用户登录成功后操作界面的函数  '''  print("="*14,"用户操作界面","="*14,"/n")  print("{0:2} {1:12} {2:12} {3:12}".format(" ","1. 查询","2. 取款","3. 存款"),"/n")  print("{0:2} {1:10} {2:12}".format(" ","4. 修改密码","5. 退出"),"/n")  print("="*42,"/n")#定义用户查询信息的函数def inquire(user_id):  '''  用户查询信息的函数  '''  print("="*14,"账号查询界面","="*14,"/n")  print("|{0:<4}|{1:<18}|{2:<9}|/n".format("账户名","卡号","余额(RMB)"))  print("|{0:<5}|{1:<20}|{2:<11}|/n".format(user_list[user_id]["name"],user_list[user_id]["numbers"],user_list[user_id]["balance"]))#定义用户取款的函数def withdrawal(amount):  '''  用户取款的函数  '''  i = user_list[user_id]["balance"]-int(amount)  if i>=0:    user_list[user_id]["balance"]-=int(amount)  else:    print("账户余额不足/n")#定义用户存款的函数def deposit(amount):  '''  用户存款的函数  '''  user_list[user_id]["balance"]+=int(amount)#定义用户修改密码的函数def change_password(old_password,new_password1,new_password2):  '''  用户修改密码的函数  '''  if old_password == user_list[user_id]["password"]:    if new_password1 == new_password2:      user_list[user_id]["password"] = new_password1      print("新密码修改成功/n")      return 1    else:      print("修改密码失败，您2次输入的新密码不一致/n")      return 2  else:    print("旧密码输入错误/n")    return 0#用户登录界面，输入银行卡号和密码chance = 3 #允许3次用户名或密码输入错误while True:  ATM()  user_name = input("请输入您的银行卡卡号：")  print("")  print("请输入您的银行卡密码:", end=' ', flush=True)  user_password = b''.join(psw_input()).decode()  print("")  user_id = check(user_name,user_password)#验证银行卡号与密码是否匹配  if user_id != None:    print("登录成功/n")    while True:      interface()      key_word = input("请输入操作选项：")      print("")      if key_word == "1":        inquire(user_id)        input("按任意键返回上一级目录:")        print("")      elif key_word == "2":        print("="*14,"账号取款界面","="*14,"/n")        amount = input("请输入取款金额：")        print("")        withdrawal(amount)        inquire(user_id)        input("按任意键返回上一级目录:")        print("")      elif key_word == "3":        print("="*14,"账号存款界面","="*14,"/n")        amount = input("请输入存款金额：")        print("")        deposit(amount)        inquire(user_id)        input("按任意键返回上一级目录:")        print("")      elif key_word == "4":        print("="*14,"密码管理界面","="*14,"/n")        print("请输入旧密码:", end=' ', flush=True)        old_password = b''.join(psw_input()).decode()        print("")        print("请输入新密码:", end=' ', flush=True)        new_password1 = b''.join(psw_input()).decode()        print("")        print("请再次输入新密码:", end=' ', flush=True)        new_password2 = b''.join(psw_input()).decode()        print("")                save = change_password(old_password,new_password1,new_password2)        #如何检测到旧密码输入有误，将直接退出        if save == 0:          break      elif key_word == "5":        print("="*14,"欢迎下次光临","="*14,"/n")        break      else:        print("="*14,"没有该选项","="*14,"/n")  else:    if chance > 1:           print("用户名或密码错误，您还有",chance-1,"次机会，请重新输入/n")      chance -= 1    else:      print("对不起，您输入用户名或密码错误已达3次")      break