title: Check if any alert exists using selenium with python
body: <p>I'm trying to write a test with selenium in python language for a web page that manages users. In this page someone can add role for users and if a role exists while adding it, an alert raises. I don't know if the alert is a javascript alert or an element of the web page. I want to automatically check the existence of the alert, because checking for the role in the list wastes time and has an enormous load. I tried this:</p>
  
  <pre><code>browser = webdriver.Firefox()
  browser.get("url")
  browser.find_the_element_by_id("add_button").click()
  try:
      alert = browser.switch_to_alert()
      alert.accept()
      print "alert accepted"
  except:
      print "no alert"
  </code></pre>
  
  <p>But it didn't work and I got the "UnexpectedAlertPresentException".
  I also tried this:</p>
  
  <pre><code>browser = webdriver.Firefox()
  browser.get("url")
  browser.find_the_element_by_id("add_button").click()
  s = set(browser.window_handles)
  s.remove(browser.current_window_handle)
  browser.switch_to_window(s.pop()) 
  </code></pre>
  
  <p>But I got the same exception.
  Additionally, I tried to access the alert with firebug to check if I can get access with its properties, but right click was disabled.
  I need a solution very quickly, even in other languages. I can understand the approach anyway.
  I will appreciate any help.</p>