def find_toast(self,message,timeout,poll_frequency,driver):
message = '//*[@text=\'{}\']'.format(message)
element = WebDriverWait(driver,timeout,poll_frequency).until(expected_conditions.presence_of_element_located((By.XPATH,message)))
print (element)
```python
这个函数是查询对应的toast,然后打印出来吧,但是为什么我运行失败了呢 1.6.4+pyhon3
"F:\001\RE_Testcase.py", line 194, in guide
self.find_toast(u'用户名密码错误',10,0.5,self.driver)
File "F:\001\RE_Testcase.py", line 72, in find_toast
element = WebDriverWait(driver,timeout,poll_frequency).until(expected_conditions.presence_of_element_located((By.XPATH,message)))
File "F:\001\selenium\webdriver\support\wait.py", line 80, in until
raise TimeoutException(message, screen, stacktrace)
selenium.common.exceptions.TimeoutException: Message: