selenium中定位frame中的元素

from selenium import webdriver
from time import  sleep

class TestCase(object):
    def __init__(self):
        self.driver = webdriver.Chrome()
        self.driver.get('http://sahitest.com/demo/framesTest.htm')
        self.driver.maximize_window()

    def test(self):
        top = self.driver.find_element_by_name('top')
        self.driver.switch_to.frame(top)
        self.driver.find_element_by_xpath('/html/body/table/tbody/tr/td[1]/a[1]').click()
        sleep(1)
        #   退出第一个frame
        self.driver.switch_to.default_content()
        sleep(1)
        #   找到第二个frame
        se = self.driver.find_element_by_xpath('/html/frameset/frame[2]')
        self.driver.switch_to.frame(se)
        self.driver.find_element_by_xpath('/html/body/table/tbody/tr/td[1]/a[2]').click()


if __name__ == '__main__':
    case = TestCase()
    case.test()
    sleep(2)
    case.driver.quit()