Python Selenium: wait until an element is no longer stale?

A stale element is an element reference that you have stored that is no longer valid because the page, part of the page, or maybe just the element was refreshed. A simple example

element = driver.find_element_by_id("elementID")# do something that refreshes the pageelement.click()

Here element.click() will throw a stale element exception because the reference was stored before the refresh but used (clicked) after the refresh. In this case, that reference is no longer valid. Once a reference is stale, it never becomes "unstale"... that reference can never be used again. The only way to fix that is to store the reference again.

NOTE: Your code sample is not correct for .staleness_of(). It takes a web element reference, not a locator. You need an existing reference to wait for it to go stale. See the docs.

Now to solve the problem... you need to wait for the refresh to complete and then get a new reference.

element = driver.find_element_by_id("elementID")# do something that refreshes the elementself.wait.until(EC.staleness_of(element))element = self.wait.until(EC.visibility_of_element_located((By.ID, "elementID")))# do something with element

Waiting for the element to become stale waits for the element reference to be lost, which means the element has changed/refreshed. Once we know the element has changed, we can now get a new reference to it. In this case, waiting for the element to become visible. We now have a new reference stored in our variable that we can use without stale element exceptions.

From the documentation:

Staleness of:

class staleness_of(object):    """ Wait until an element is no longer attached to the DOM.    element is the element to wait for.    returns False if the element is still attached to the DOM, true otherwise.    """    def __init__(self, element):        self.element = element    def __call__(self, ignored):        try:            # Calling any method forces a staleness check            self.element.is_enabled()            return False        except StaleElementReferenceException:            return True

Element to be clickable:

class element_to_be_clickable(object):    """ An Expectation for checking an element is visible and enabled such that    you can click it."""    def __init__(self, locator):        self.locator = locator    def __call__(self, driver):        element = visibility_of_element_located(self.locator)(driver)        if element and element.is_enabled():            return element        else:            return False

As you can see, both use the same method is_enabled() in order to perform the check.

As you want to pick up the text property once the WebElement is no longer stale, you can use the following :

wait1 = WebDriverWait(driver, 10)wait1.until(expected_conditions.text_to_be_present_in_element((By.ID, "elementID"), "expected_text1"))

OR

wait2 = WebDriverWait(driver, 10)wait2.until(expected_conditions.text_to_be_present_in_element_value((By.ID, "elementID"), "expected_text2"))