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You may be getting an interesting error when you try to use an element on a page, such as reading a value from it or clicking on it. This is because when you try to invoke the action, the page hasn’t fully loaded the elements into the DOM. Use the following code courtesy of Gregor to get around the problem

from selenium.webdriver.support.ui import WebDriverWait

element_id = object

def find_the_element_by_id(driver, element_id):
    element = driver.find_element_by_id(element_id)
    if element:
        return element
    else:
        return False

def function_where_test_written():
    global element_id
    
    element_id = "qa"
    qa = WebDriverWait(driver, 1).until(find_the_element_by_id)
    qa.click()

Code explained

Line 1 3 : set up a variable that we can pass the id or whatever the search criteria is into

Line 35-8 10 : create a function that does the query on the DOM using the webdriver that is passed in

Line 11 15 : specify the thing that you want search for

Line 12 16 : use a special API call WebDriverWait() that tells the webdriver (the first parameter being passed in) to wait for a certain period (the second parameter, in this example up to 1 second) until calling your query function “find_the_element_by_id” - this is passed into the until() method. Essentially it causes the WebDriver to slow down until the DOM is stable (in other words the page has been properly loaded).

Line 13 17 : perform your action on the element as normal

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