MaxRetryError：HTTPConnectionPool：超过最大重试次数（由ProtocolError（“连接中止。”，错误（111，“连接被拒绝”）引起））

Question

我有一个问题：我想测试“选择”和“输入”。我可以像下面的代码一样写吗：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 
     33         
     34

我想测试Selenium的“选择”功能。所以我选择sina网站选择一个选项，然后在textarea中输入文本。然后搜索它。但是当我运行此测试时，它有错误：

 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')))

…表示该 get() 方法无法引发 MaxRetryError 。

有两件事：

• 首先，根据讨论，max-retries-exceeded异常令人困惑， 回溯 有些误导。请求包装异常是为了方便用户。原始异常是显示的消息的一部分。

• 请求永不重试（它retries=0为urllib3 设置了HTTPConnectionPool），因此如果没有 MaxRetryError 和 HTTPConnectionPool 关键字，则错误将更为规范。因此理想的 回溯 应该是：

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

• 但是@ sigmavirus24在他的评论中再次提到 …包装这些异常会产生出色的API，但会带来不良的调试体验…

• 向前推进的计划是 尽可能向下遍历最低级别的异常，并使用它。

• 最后，通过改写一些与实际连接被拒绝错误无关的异常来解决此问题。

解

由于按照 发行说明 的 硒3.14.1 ：

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

该 合并 是：维修urllib3不能设置超时！

结论

升级到 Selenium 3.14.1之后， 您将可以设置超时并查看规范的 回溯 ，并且可以采取必要的措施。

参考资料

几个相关的事件引用：

• 添加max_retries作为参数
• 删除了捆绑的charade和urllib3。
• 第三方图书馆逐字承诺