登录操作（方法二：for与else搭配）

登录操作（方法二：for与else搭配）

user_name="star"
passwoed='123'

count=0
for i in range(3):
    u_username=input("please input your username:")
    u_password=input("please input your password:")

    if u_username==user_name and u_password==passwoed:
        print("welcome to %s"%u_username)
        break
    else:
        count+=1
        print("your username or password is Error")
else:
    count==3
    print("you have try more times,would you want to try again? please input yes or no,please choose")
    answer=input("your choose:")
    if answer=='yes':
        print("go away,hahahah")
Output:错误操作

please input your username:aaa
please input your password:a
your username or password is Error
please input your username:a
please input your password:a
your username or password is Error
please input your username:a
please input your password:a
your username or password is Error
you have try more times,would you want to try again? please input yes or no,please choose
your choose:yes
go away,hahahah

进程已结束,退出代码0

Input:错误操作

please input your username:star
please input your password:123
welcome to star

进程已结束,退出代码0