Python实现ATM系统

def index(nowUser):
 print('=' * 10, '自动存取款机', '=' * 10)
 print(getName(nowUser), '欢迎登陆！')
 print('{:<10}{:^10}{:<10}'.format('1.修改密码', ' ', '2.查询余额'))
 print('{:<10}{:^12}{:<10}'.format('3.存钱', ' ', '4.取钱'))
 print('输入\'exit\'退出操作')

def getId(nowUser):
 '''获取当前用户在列表中的位置'''
 index = -1
 for i in range(len(userList)):
  if userList[i]['cardid'] == nowUser:
   index = i # 如果用户存在则返回它在列表中的下标
   break
 return index # 如果用户不存在则返回-1


def getName(nowUser):
 ''' 获取用户姓名'''
 index = getId(nowUser)
 return userList[index]['name']


def checkUser(cardid, password):
 '''自定义用户检测功能，包括卡号及密码检测'''
 index = getId(cardid)
 if index == -1: # 如果用户不存在
  return 'noCardId' # 卡号不存在
 else:
  if userList[index]['cardid'] == cardid and userList[index]['password'] == password: # 用户存在并且账号密码正确
   return 'login' # 密码正确
  else:
   return 'errorPW' # 密码错误

def showMoney(nowUser):
 '''查询余额'''
 index = getId(nowUser)
 print('您当前的账户余额为：', userList[index]['money'], '元')

def saveMoney(nowUser, money):
 '''存钱'''
 index = getId(nowUser)
 print("输入的金额是：", money)
 userList[index]['money'] += int(money)
 print('存入成功！')

def drawMoney(nowUser, money):
 '''取钱'''
 index = getId(nowUser)
 nowMoney = userList[index]['money']
 if nowMoney >= int(money):
  userList[index]['money'] -= int(money)
  print('已取出', money, '元')
 else:
  print('账户余额不足！')

def changePW(nowUser, newPW):
 '''修改密码'''
 index = getId(nowUser)
 userList[index]['password'] = newPW

# 用户操作
def userChoice(nowUser):
 choices = ['1', '2', '3', '4', 'exit']
 # 循环获取用户操作
 while True:
  index(nowUser)
  choice = input('请选择操作：')
  if choice == '1': # 选择修改密码
   oldPW = input('请输入原始密码:')
   flag = checkUser(nowUser, oldPW)
   if flag == "errorPW":
    # print('密码错误！请重新输入，或输入\'back\'返回上一级')
    print('密码错误!返回主界面')
   elif flag == 'login':
    changePW(nowUser, input('请输入新密码：'))
    print('修改密码成功！')
    continue
  elif choice == '2': # 选择查询余额
   showMoney(nowUser)
   continue
  elif choice == '3': # 选择存钱
   saveMoney(nowUser, input('请输入存入金额：'))
   continue
  elif choice == '4': # 选择取钱
   drawMoney(nowUser, input('请输入取出金额：'))
   continue
  elif choice == 'exit':
   main() # 返回主界面
  elif choice not in choices:
   print('错误操作，请重新输入选项!')
   continue

# 主界面
def main():
 # 定义错误次数
 errorTime = 0
 if errorTime >= 3: # 错误次数达三次退出系统后清零
  errorTime = 0
 while True:
  # crs登陆主界面
  print('=' * 10, '自动存取款机', '=' * 10)
  nowUser = ''
  # 用户输入卡号和密码
  cardid = input('请输入卡号：')
  password = input('请输入密码：')

  # 判断卡号密码是否存在正确
  # 卡号不存在
  flag = checkUser(cardid, password)

  if flag == 'noCardId':
   print('卡号不存在！请重新输入')
   continue

  # 密码错误
  elif flag == 'errorPW':
   errorTime += 1
   print('密码错误！错误次数达三次将自动退出本系统！')
   print("错误次数：", errorTime)
   if errorTime >= 3: # 错误次数达三次自动退出
    print('密码输错三次，自动退出系统！')
    exit(0)
   continue

  # 卡号密码正确进入系统
  else:
   nowUser = cardid
   userChoice(nowUser)

if __name__ == '__main__':

 main()