Why is Selenium not finding elements (pythonanywhere)?

Question

Python

Everything works fine locally. Deployed the project to the server - problem:

Page title was 'Login • Instagram'
Message: no such element: Unable to locate element: {"method":"xpath","selector":"//div[@class="_5wCQW" ]//video"}
(Session info: headless chrome=78.0.3904.70)

Message: no such element: Unable to locate element: {"method":"xpath","selector":"//div[@class="KL4Bh"]//img"}
(Session info: headless chrome=78.0. 3904.70)

The problem is with Instagram, it reads other resources successfully.

What could it be? Authorization on Instagram is also successful, there is no blocking. I increased the time, set implicit waits .. nothing helps ..

Code:

def check_xpath_exists(driver, xpath_element, one_URL): #  метод проверяет по xpath существует ли элемент на странице
    try:
        driver.find_element_by_xpath(xpath_element)
        exist = True # если элемент найден
    except NoSuchElementException as e:
        print(e)
        exist = False
    return exist

chromedriver_autoinstaller.install()
chrome_options = webdriver.ChromeOptions()
chrome_options.add_argument("--headless") # запуск в фоном режиме
chrome_options.add_argument("--disable-gpu")
                       
driver = webdriver.Chrome(options=chrome_options)
try:
      # # ------ тестирование веб драйвера на поиск элементов по xpath ------------
     # driver.get("https://www.google.com") # https://help.pythonanywhere.com/pages/selenium/                 
     # if check_xpath_exists(driver, "/html/body/div[1]/div[3]/form/div[1]/div[1]/div[3]/center/input[1]", "https://www.google.com") == True:
             #  print('Найден')

     # authorize(driver)
     driver.get("https://www.instagram.com/p/CShQ6YCiX5u/")
     sleep(3)
     xpath_for_img = '//div[@class="KL4Bh"]//img' # универсальный xpath - находит все изображения в аккаунте юзера 
     xpath_for_video = '//div[@class="_5wCQW"]//video'
     if check_xpath_exists(driver, xpath_for_video, "https://www.instagram.com/p/CShQ6YCiX5u/") == True: 
           print('Найден')                
     if check_xpath_exists(driver, xpath_for_img, "https://www.instagram.com/p/CShQ6YCiX5u/") == True:
          print('Найден')
                 
 finally: # выполняет в любом случае, было ли исключение, или нет 
          # driver.close() # закрытие активной вкладки
          driver.quit() # завершение работы драйвера

instagram whitelisted - https://www.pythonanywhere.com/whitelist/
Example:
https://www.youtube.com/watch?v=hibhU5Rqt1s , https://github.com/bjcarlson42/youtube/blob/master ...

Answer 1

I can't say for sure, but 95% of problems with Selenium are problems with timing. For example, the element did not have time to be drawn. Try waiting to add