def login1(username,password):time.sleep(1)if username is not None:driver.find_element(By.CSS_SELECTOR, "#username").send_keys(username)if password is not None:driver.find_element(By.CSS_SELECTOR,'#password').send_keys(password)driver.find_element(By.CSS_SELECTOR,'#loginBtn').click()time.sleep(1)# alert=driver.switch_to.alert.text# driver.switch_to.alert.accept()# return alert我把后三行注释掉了 按道理没有返回值 也没有get到alert的文本 但是def test_0001(self,clearAlert):alert1=login.login1(None,'sdfsdf')time.sleep(1)assert alert1=="请输入用户名"这个测试用例还是通过的 是为什么啊 各位大佬