当前窗口句柄与切换回原窗口句柄

import unittest,time,re
from selenium import webdriver

class Untitled(unittest.TestCase):
    def setUp(self):
        self.driver = webdriver.Chrome()
        self.driver.implicitly_wait(10)
        self.url = "http://www.baidu.com"

    def test_Untitled (self):
        driver = self.driver
        driver.get(self.url)
        now_handle = driver.current_window_handle #获取当前窗口句柄
        print (now_handle)   #输出当前获取的窗口句柄
        driver.find_element_by_id("kw").send_keys("葵花")
        driver.find_element_by_id("su").click()
        driver.find_element_by_partial_link_text("www.xxxx.com/kuihua ").click() #点击链接跳转新标签页
        time.sleep(2)
        all_handles = driver.window_handles #获取所有窗口句柄

        for handle in all_handles:

            if handle != now_handle:
                print (handle)    #输出待选择的窗口句柄
                driver.switch_to_window(handle) #绑定
                driver.find_element_by_id("blog_nav_sitehome").click()
                time.sleep(5)
                driver.close() #关闭当前窗口
        time.sleep(3)
        print (now_handle)   #输出主窗口句柄
        driver.switch_to_window(now_handle) #返回主窗口
        time.sleep(2)
        driver.find_element_by_id("kw").clear()
        driver.find_element_by_id("kw").send_keys("12306")
        driver.find_element_by_id("su").click()

        time.sleep(10)

    def tearDown(self):
        self.driver.quit()
        #pass


if __name__ == "__main__":
    unittest.main()