I am getting the following error while using Selenium in python:
selenium.common.exceptions.StaleElementReferenceException: Message: u'stale element reference: element is not attached to the page document\n
Interestingly enough, the error pops up at different times in the for loop. Sometimes it gets through eg. 4 iterations and other times eg. 7.
Some of the relevant code being run is:
for i in range(0, 22):
u = driver.find_elements_by_id("data")
text = u[0].get_attribute("innerHTML")
driver.find_elements_by_class_name("aclassname")[0].click()
What does this error mean and what is something I can try to fix this?
It means the element is no longer in the DOM, or it changed.
The following code will help you find the element by controlling and ignoring StaleElementExceptions and handling them just like any other NoSuchElementException. It waits for the element to NOT be stale, just like it waits for the element to be present. It also serves as a good example on how to properly wait for conditions in Selenium.
from selenium.common.exceptions import NoSuchElementException
from selenium.common.exceptions import StaleElementReferenceException
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions
my_element_id = 'something123'
ignored_exceptions=(NoSuchElementException,StaleElementReferenceException,)
your_element = WebDriverWait(your_driver, some_timeout,ignored_exceptions=ignored_exceptions)\
.until(expected_conditions.presence_of_element_located((By.ID, my_element_id)))
To better understand the problem, imagine you are inside a for loop and think what happens during the iterations: