selenium多窗口切换定位

from selenium import webdriver
import unittest,time,re
from selenium.webdriver.common.keys import Keys

'''
元交网登录退出
'''

username=''
password=''

class Untitled(unittest.TestCase):
    def setUp(self):
        # 打开网址
        self.driver=webdriver.Firefox()
        self.driver.implicitly_wait(10)
        self.url="https://ca.cecb2b.com/login"
        self.driver.maximize_window()

    def shop_buy(self):
        driver=self.driver
        driver.get(self.url)
        # 登录
        driver.find_element_by_xpath("//input[@id='username']").clear()
        driver.find_element_by_xpath("//input[@id='username']").send_keys(username)
        self.driver.implicitly_wait(10)
        driver.find_element_by_xpath("//input[@class='text_inps1 text_inps2']").send_keys(password)
        driver.find_element_by_xpath("//input[@type='submit']").click()
        driver.find_element_by_xpath("//a[contains(text(),'元器件交易网-全球领先电子配套平台')]").click() #元交网首页

        now_handle=driver.current_window_handle  #获取当前窗口句柄
        print("----now handle id first is %s"%now_handle)

        # 购买某产品
        driver.find_element_by_xpath("//*[@class='buy-now']").find_element_by_link_text('立即购买').click()
        # driver.implicitly_wait(10)
        time.sleep(2)

        all_handles = self.driver.window_handles #获取所有窗口的句柄
        # 将所有窗口id遍历一遍，将最新的写入到txt中
        filename='write_data.txt'
        with open(filename, 'w') as f:
            for i in range(len(all_handles)):
                  f.write(str(all_handles[i]+"\n"))

        time.sleep(2) #增加延迟，以确保浏览器响应
        # print("---新页面id is %s 旧页面id is %s"%(all_handles[1],now_handle))

        # 进入购物车
        driver.switch_to_window(all_handles[-1])
        time.sleep(1)
        driver.find_element_by_xpath("//div[@class='gauge']/a[1]").click()
        time.sleep(1)
        # print(now_handle)

        # 进入结算
        time.sleep(2)
        self.driver.find_element_by_xpath("//input[@id='inlandAllTop']").click() # 复选框checkbox
        time.sleep(2)
        self.driver.find_element_by_xpath("//div[@class='company-list']/input[1]").send_keys(Keys.SPACE) #选择第一个checkbox
        if driver.find_element_by_xpath("//div[@class='company-list']/input[1]").is_selected():
            print('selected!')
        else:
            print('not yet!')
        time.sleep(1)
        self.driver.find_element_by_xpath("//a[@class='accounts']").click()
        time.sleep(2)

        self.driver.find_element_by_link_text("提交订单").click()
        time.sleep(2)
        self.driver.find_element_by_link_text("国内交货支付").click()

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

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