title: Error while switching window in python selenium
body: <p>I want to work with multiple windows and tabs using selenium and python.</p>
  
  <p>I am getting below error during script execution:- 
  ( code is mentioned at last)</p>
  
  <pre><code>{f625f26d-cfcf-442c-b9fc-5e96a199cd43}
  C:\Python34\lib\site-packages\selenium-2.47.1- py3.4.egg\selenium\webdriver\remot
  e\webdriver.py:525: DeprecationWarning: use driver.switch_to.window instead
   warnings.warn("use driver.switch_to.window instead", DeprecationWarning)
   {cad6e3cf-9062-408e-a6f1-11e98813dc6c}
  </code></pre>
  
  <hr>
  
  <pre><code>import unittest
  from selenium import webdriver
  from selenium.webdriver.common.keys import Keys
  from selenium.webdriver.common.by import By
  
  class GoogleTabs(unittest.TestCase):
  
   def setUp(self):
       self.driver = webdriver.Firefox()
  
   def test_google_search_page(self):
       driver = self.driver
       driver.get("http://www.cdot.in")
       window_before = driver.window_handles[0]
       print (window_before)
       driver.find_element_by_xpath("//a[@href='http://www.cdot.in/home.htm']").click()
       window_after = driver.window_handles[1]
       driver.switch_to_window(window_after)
       print (window_after)
       driver.find_element_by_link_text("ATM").click()
       driver.switch_to_window(window_before)
  
  
   def tearDown(self):
       self.driver.close()
  
  if __name__ == "__main__":
  unittest.main()
  </code></pre>