登录认证

用户跳转一个界面就要输入一次密码，所以通过设置一个状态值，来保存以登录的状态

def auth():
    username = input("username:").strip()
    password = input("password:").strip()
    #get data from db
    _username = "a"
    _password = "a"
    if username == _username and password == _password:
        print("passed authentication!")
        global login_status
        login_status = True #局部变量
        print("-->",login_status)
        return True, 1,2
        print("after return ....")
    else:
        return False

def home():
    if login_status == True:
        print("welcome to home page")
    else:
        auth()
def pay():
    if login_status == True:
        print("welcome to pay page")
    else:
        auth()

login_status = auth()
print(login_status)

# print(login_status)
auth()
home()
pay()