day1初次尝试

#Author:walter
_username = 'walter'
_password = '12345678'
i=1
while True:
    username = input("username: ")
    password = input("password: ")
    if  username ==_username and password ==_password:
        print("Welcome user {name} login...".format(name=username))
        break
    elif username == _username and password != _password:
        print("the password is wrong")
        i += 1
        if i > 3:
            print("the user {name} is locked".format(name=username))
    else:
        print("username is non-existent")
else:
    print("username is non-existent")