“Cómo cambiar el controlador en Python Selenium” Código de respuesta

Cómo cambiar el controlador en Python Selenium

import unittest
from selenium import webdriver
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.common.by import By

class GoogleOrgSearch(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()