网页页面之间的切换

from selenium import webdriver
import  time


driver=webdriver.Chrome()
driver.get("http://www.douban.com/")
time.sleep(2)
driver.execute_script('window.open("http:www.163.com/")')
time.sleep(2)
driver.execute_script('window.open("http:www.jd.com/")')
time.sleep(2)
driver.execute_script('window.open("http:www.baidu.com/")')

#回到第一个页面
pages=driver.window_handles
driver.switch_to.window(pages[0])