title: Python Selenium Could not select dependent second dropdown after selecting first dropdown
body: <p>I am trying to scrape <a href="https://www.autotrader.com/model-information" rel="nofollow noreferrer">https://www.autotrader.com/model-information</a> and get all combinations make-model of dropdown values (such as Audi-a4, Audi-a6, etc).</p>
  <p>I can click and select the values from the first dropdown (car make dropdown) without a problem. But when I try to click and select the value in the second dropdown (model dropdown), TimeoutException error shows up.</p>
  <p>[error like this][1] [1]: https://i.stack.imgur.com/mLM5h.png</p>
  <p>Looks like the second dropdown cannot be clicked thus the option values cannot be showed while using chromedriver. When I browse the website and click the first dropdown myself, the second dropdown become clickable immediately and all values show up in the dropdown.</p>
  <p>I do not know how to fix this since the url, ID, XPATH, nothing change after choosing values of the first dropdown.</p>
  <p>It may be something to do with anti-blocking. Maybe the website recognize I am a bot and block me from scraping.</p>
  <p>Here is my code:</p>
  <pre><code>driver = webdriver.Chrome(executable_path='/opt/anaconda3/bin/chromedriver')   
   ### paste chromedriver path as executable_path here
  driver.maximize_window()
  url = &quot;https://www.autotrader.com/model-information&quot; 
  driver.get(url)
  
  makelist=[]
  modellist=[]
  #### First work with the drop down menus with car makes 
  driver.find_element_by_xpath('//*[@id=&quot;makeCode&quot;]').click()
  make = driver.find_elements_by_xpath('//*[@id=&quot;makeCode&quot;]/optgroup[@label=&quot;All Makes&quot;]/option')
  #### Loop through all makes in the drop down menus
  for makeele in make:
      makelist.append(makeele.get_attribute('text'))
      makeele.click()
      time.sleep(3)
      
      #### Work with the drop down menus with car models of specific make
      wait = WebDriverWait(driver, 20)
      wait.until(EC.element_to_be_clickable((By.XPATH,'//*[@id=&quot;ModelCode&quot;]'))).click()
      model = driver.find_elements_by_xpath('//*[@id=&quot;ModelCode&quot;]/optgroup[2]/option')
      #### Loop through all models in the drop down menus
      for modelele in model:
          modellist.append(modelele.get_attribute('text'))
          modelele.click()
          time.sleep(3)
  </code></pre>
  <p>I appreciate any suggestion.</p>