#1、验证输入账号密码的正确性
username = "cwb"
password = "123456"
_user = input("请输入账号：")
_passwd = input("请输入密码：")
if _user == username and _passwd == password:
    print("login in sucess!!,welcome!!")
else:
    print("failed!!")

#2、尝试3次输入账号密码，输入3次后程序退出
username = "cwb"
password = "123456"
for i in range(3):
    _user = input("请输入账号：")
    _passwd = input("请输入密码：")
    if _user == username and _passwd == password:
     print("login in sucess!!,welcome!!")
     break
    else:
     print("failed!!")

#3、输入3次后提示 输入已达到上限，程序退出
username = "cwb"
password = "123456"
count = 0
for i in range(4):
   if count == 3:
     print("尝试此数已达上限，程序退出！！！！")
     break
   user = input("请输入账号：")
   passwd = input("请输入密码：")
   if user == username and passwd == password:
        print("login in sucess!!,welcome!!")
        break
   else:
          print("failed!!")
   count += 1

#4、输入3次后提示 输入已达到上限，输入Y继续，输入N退出

username = "cwb"
password = "123456"
count = 0
for i in range(10):
   if count == 3:
        msg = input("继续输入Y，退出输入N:")
        if  msg == "Y":
            count = 0
        else:
            print("尝试此数已达上限，程序退出！！！！")
            break
   user = input("请输入账号：")
   passwd = input("请输入密码：")
   if user == username and passwd == password:
        print("login in sucess!!,welcome!!")
        break
   else:
          print("failed!!")
   count += 1