python - MaxRetryError : HTTPConnectionPool: Max retries exceeded (Caused by ProtocolError ('Connection aborted.' ,错误(111， 'Connection refused')))

Question

我有一个问题:我想测试“select”和“input”。我可以像下面的代码那样写吗:原始代码:

 12 class Sinaselecttest(unittest.TestCase):
 13 
 14     def setUp(self):
 15         binary = FirefoxBinary('/usr/local/firefox/firefox')
 16         self.driver = webdriver.Firefox(firefox_binary=binary)
 17 
 18     def test_select_in_sina(self):
 19         driver = self.driver
 20         driver.get("https://www.sina.com.cn/")
 21         try:
 22             WebDriverWait(driver,30).until(
 23                 ec.visibility_of_element_located((By.XPATH,"/html/body/div[9]/div/div[1]/form/div[3]/input"))
 24             )
 25         finally:
 26             driver.quit()
 # #测试select功能
 27         select=Select(driver.find_element_by_xpath("//*[@id='slt_01']")).select_by_value("微博")
 28         element=driver.find_element_by_xpath("/html/body/div[9]/div/div[1]/form/div[3]/input")
 29         element.send_keys("杨幂")
 30         driver.find_element_by_xpath("/html/body/div[9]/div/div[1]/form/input").click()
 31         driver.implicitly_wait(5)

 32    def tearDown(self):
 33        self.driver.close()

我想测试Selenium的“选择”功能。所以我选择新浪网站选择一个选项并在textarea中输入文本。然后搜索它。但是当我运行此测试时，出现错误:

 Traceback (most recent call last):
      File "test_sina_select.py", line 32, in tearDown
        self.driver.close()
      File "/usr/lib/python2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 688, in close
        self.execute(Command.CLOSE)
      File "/usr/lib/python2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 319, in execute
        response = self.command_executor.execute(driver_command, params)
      File "/usr/lib/python2.7/site-packages/selenium/webdriver/remote/remote_connection.py", line 376, in execute
        return self._request(command_info[0], url, body=data)
      File "/usr/lib/python2.7/site-packages/selenium/webdriver/remote/remote_connection.py", line 399, in _request
        resp = self._conn.request(method, url, body=body, headers=headers)
      File "/usr/lib/python2.7/site-packages/urllib3/request.py", line 68, in request
        **urlopen_kw)
      File "/usr/lib/python2.7/site-packages/urllib3/request.py", line 81, in request_encode_url
        return self.urlopen(method, url, **urlopen_kw)
      File "/usr/lib/python2.7/site-packages/urllib3/poolmanager.py", line 247, in urlopen
        response = conn.urlopen(method, u.request_uri, **kw)
      File "/usr/lib/python2.7/site-packages/urllib3/connectionpool.py", line 617, in urlopen
        release_conn=release_conn, **response_kw)
      File "/usr/lib/python2.7/site-packages/urllib3/connectionpool.py", line 617, in urlopen
        release_conn=release_conn, **response_kw)
      File "/usr/lib/python2.7/site-packages/urllib3/connectionpool.py", line 617, in urlopen
        release_conn=release_conn, **response_kw)
      File "/usr/lib/python2.7/site-packages/urllib3/connectionpool.py", line 597, in urlopen
        _stacktrace=sys.exc_info()[2])
      File "/usr/lib/python2.7/site-packages/urllib3/util/retry.py", line 271, in increment
        raise MaxRetryError(_pool, url, error or ResponseError(cause))
    MaxRetryError: HTTPConnectionPool(host='127.0.0.1', port=51379): Max retries exceeded with url: /session/2e64d2a1-3c7f-4221-96fe-9d0b1c102195/window (Caused by ProtocolError('Connection aborted.', error(111, 'Connection refused')))
    
    ----------------------------------------------------------------------
    Ran 1 test in 72.106s

谁能告诉我为什么？谢谢

Answer 1

此错误消息...

MaxRetryError: HTTPConnectionPool(host='127.0.0.1', port=51379): Max retries exceeded with url: /session/2e64d2a1-3c7f-4221-96fe-9d0b1c102195/window (Caused by ProtocolError('Connection aborted.', error(111, 'Connection refused')))

...意味着调用 self.driver.close() 方法失败，引发 MaxRetryError。

<小时/>

有几件事:

• 首先也是最重要的，根据讨论 max-retries-exceeded exceptions are confusing 回溯有点误导。为了用户的方便，请求包装了异常。原始异常是显示消息的一部分。

• 请求从不重试(它为 urllib3 的 HTTPConnectionPool 设置了 retries=0)，因此如果没有 MaxRetryError，错误会更加规范 和 HTTPConnectionPool 关键字。因此，理想的回溯应该是:

    ConnectionError(<class 'socket.error'>: [Errno 1111] Connection refused)
  

• 但是@sigmavirus24又在他的comment中提到...包装这些异常可以提供一个很棒的 AP​​I，但调试体验很差...

• 接下来的计划是尽可能向下遍历到最低级别的异常并使用它。

• 最后，通过重新措辞一些与实际连接拒绝错误无关的异常，解决了这个问题。

<小时/>

解决方案

即使在调用 tearDown(self) 中的 self.driver.close() 之前， 中的 try{} block test_select_in_sina(self) 包含您调用 driver.quit() 的finally{}，该函数用于调用/shutdown端点以及随后的网络驱动程序和客户端实例被完全销毁，关闭所有页面/选项卡/窗口。因此不再存在连接。

You can find a couple of relevant detailed discussion in:

• PhantomJS web driver stays in memory
• Selenium : How to stop geckodriver process impacting PC memory, without callingdriver.quit()?

在这种情况下，当您调用 self.driver.close() 时 python客户端无法找到任何事件连接来发起关闭。因此您会看到错误。

因此，一个简单的解决方案是删除 driver.quit() 行，即删除 finally block 。

<小时/>

tl;博士

根据 Selenium 3.14.1 的发行说明:

* Fix ability to set timeout for urllib3 (#6286)

合并是:repair urllib3 can't set timeout!

<小时/>

结论

升级到Selenium 3.14.1后，您将能够设置超时并查看规范的回溯，并能够采取所需的操作。

<小时/>

引用文献

一些相关引用:

• Adding max_retries as an argument
• Removed the bundled charade and urllib3.
• Third party libraries committed verbatim