Python 为什么Selenium不切换到给定的帧？

我有以下Selenium Python脚本（python3的完整工作示例）：

运行脚本时，我收到以下错误：

======================================================================
ERROR: test_1 (__main__.Test1)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "E:/Privat/Learn/Selenium/test2.py", line 23, in test_1
    driver.switch_to.frame("menu")
  File "C:\Program Files (x86)\Python 3.5\lib\site-packages\selenium\webdriver\remote\switch_to.py", line 67, in frame
    self._driver.execute(Command.SWITCH_TO_FRAME, {'id': frame_reference})
  File "C:\Program Files (x86)\Python 3.5\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 201, in execute
    self.error_handler.check_response(response)
  File "C:\Program Files (x86)\Python 3.5\lib\site-packages\selenium\webdriver\remote\errorhandler.py", line 181, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.NoSuchFrameException: Message: Unable to locate frame: menu
Stacktrace:
    at FirefoxDriver.prototype.switchToFrame (file:///C:/Users/dial1/AppData/Local/Temp/tmpyz7v7fdj/extensions/fxdriver@googlecode.com/components/driver-component.js:10729)
    at DelayedCommand.prototype.executeInternal_/h (file:///C:/Users/dial1/AppData/Local/Temp/tmpyz7v7fdj/extensions/fxdriver@googlecode.com/components/command-processor.js:12534)
    at fxdriver.Timer.prototype.setTimeout/<.notify (file:///C:/Users/dial1/AppData/Local/Temp/tmpyz7v7fdj/extensions/fxdriver@googlecode.com/components/command-processor.js:621)

----------------------------------------------------------------------
Ran 1 test in 34.349s

FAILED (errors=1)

======================================================================
错误：测试1（主测试1）
----------------------------------------------------------------------
回溯（最近一次呼叫最后一次）：
文件“E:/Privat/Learn/Selenium/test2.py”，第23行，测试1
驱动程序。切换到框架（“菜单”）
文件“C:\Program Files（x86）\Python 3.5\lib\site packages\selenium\webdriver\remote\switch\u to.py”，第67行，在框架中
self._driver.execute（Command.SWITCH_TO_FRAME，{'id'：FRAME_reference}）
文件“C:\Program Files（x86）\Python 3.5\lib\site packages\selenium\webdriver\remote\webdriver.py”，第201行，执行
self.error\u handler.check\u响应（响应）
文件“C:\Program Files（x86）\Python 3.5\lib\site packages\selenium\webdriver\remote\errorhandler.py”，第181行，在check\u响应中
引发异常类（消息、屏幕、堆栈跟踪）
selenium.common.exceptions.NoSuchFrameException:消息：无法找到帧：菜单
堆栈跟踪：
在FirefoxDriver.prototype.switchToFrame(file:///C:/Users/dial1/AppData/Local/Temp/tmpyz7v7fdj/extensions/fxdriver@googlecode.com/components/driver component.js:10729）
在DelayedCommand.prototype.executeInternal\uh处(file:///C:/Users/dial1/AppData/Local/Temp/tmpyz7v7fdj/extensions/fxdriver@googlecode.com/components/command processor.js:12534）
在fxdriver.Timer.prototype.setTimeout/中，必须切换回“默认”窗口，请参阅固定代码。然而，这似乎没有记录

# -*- coding: utf-8 -*-
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.support.ui import Select
from selenium.common.exceptions import NoSuchElementException
from selenium.common.exceptions import NoAlertPresentException
import unittest, time, re

class Test1(unittest.TestCase):
    def setUp(self):
        self.driver = webdriver.Firefox()
        self.driver.implicitly_wait(30)
        self.base_url = "http://ironspider.ca/"
        self.verificationErrors = []
        self.accept_next_alert = True

    def test_1(self):
        driver = self.driver
        driver.get(self.base_url + "/frames/frames_example1/advanced.htm")
        driver.switch_to.frame("content")
        self.assertEqual("The Eve of the War", driver.find_element_by_css_selector("h2").text)
        driver.switch_to.default_content()
        driver.switch_to.frame("menu")
        driver.find_element_by_link_text("Chapter 2").click()
        driver.switch_to.default_content()
        driver.switch_to.frame("content")
        self.assertEqual("The Falling Star", driver.find_element_by_css_selector("h2").text)

    def is_element_present(self, how, what):
        try: self.driver.find_element(by=how, value=what)
        except NoSuchElementException: return False
        return True

    def is_alert_present(self):
        try: self.driver.switch_to_alert()
        except NoAlertPresentException: return False
        return True

    def close_alert_and_get_its_text(self):
        try:
            alert = self.driver.switch_to_alert()
            alert_text = alert.text
            if self.accept_next_alert:
                alert.accept()
            else:
                alert.dismiss()
            return alert_text
        finally: self.accept_next_alert = True

    def tearDown(self):
        self.driver.quit()
        self.assertEqual([], self.verificationErrors)

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

指出
驱动程序.switch\u to.default\u content（）
行可能会有所帮助。也许代码中有注释？类似于
#注意这一行
。乍一看，您的解决方案并不明显。您使用的是什么版本的Selenium？我不记得以前有过这样的经历。如果我使用的是您需要的早期版本，您的问题可能表明在以后的版本中引入了错误。
# -*- coding: utf-8 -*-
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.support.ui import Select
from selenium.common.exceptions import NoSuchElementException
from selenium.common.exceptions import NoAlertPresentException
import unittest, time, re

class Test1(unittest.TestCase):
    def setUp(self):
        self.driver = webdriver.Firefox()
        self.driver.implicitly_wait(30)
        self.base_url = "http://ironspider.ca/"
        self.verificationErrors = []
        self.accept_next_alert = True

    def test_1(self):
        driver = self.driver
        driver.get(self.base_url + "/frames/frames_example1/advanced.htm")
        driver.switch_to.frame("content")
        self.assertEqual("The Eve of the War", driver.find_element_by_css_selector("h2").text)
        driver.switch_to.default_content()
        driver.switch_to.frame("menu")
        driver.find_element_by_link_text("Chapter 2").click()
        driver.switch_to.default_content()
        driver.switch_to.frame("content")
        self.assertEqual("The Falling Star", driver.find_element_by_css_selector("h2").text)

    def is_element_present(self, how, what):
        try: self.driver.find_element(by=how, value=what)
        except NoSuchElementException: return False
        return True

    def is_alert_present(self):
        try: self.driver.switch_to_alert()
        except NoAlertPresentException: return False
        return True

    def close_alert_and_get_its_text(self):
        try:
            alert = self.driver.switch_to_alert()
            alert_text = alert.text
            if self.accept_next_alert:
                alert.accept()
            else:
                alert.dismiss()
            return alert_text
        finally: self.accept_next_alert = True

    def tearDown(self):
        self.driver.quit()
        self.assertEqual([], self.verificationErrors)

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