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I have a small script that repeatedly (hourly) fetches tweets from the API, using sixohsix's Twitter Wrapper for Python. I am successful with handling most, if not all of the errors coming from the Twitter API, i.e. all the 5xx and 4xx stuff.

Nonetheless I randomly observe the below error traceback (only once in 2-3 days). I mean the program exits and the traceback is displayed in the shell. I have no clue what this could mean, but think it is not directly related to what my script does since it has proved itself to correctly run most of the time.

This is where I call a function of the wrapper in my script:

KW = {
        'count': 200, # number of tweets to fetch (fetch maximum)
        'user_id' : tweeter['user_id'],
        'include_rts': 'false', # do not include native RT's 
        'trim_user' : 'true', 
     }
     timeline = tw.twitter_request(tw_endpoint,\
         tw_endpoint.statuses.user_timeline, KW)

The function tw.twitter_request(tw_endpoint, tw_endpoint.statuses.user_timeline, KW) basically does return tw_endpoint.statuses_user_timeline(**args), where args translate to KW, and tw_endpoint is an OAuthorized endpoint gained from using the sixohsix's library's 

return twitter.Twitter(domain='api.twitter.com', api_version='1.1',
                    auth=twitter.oauth.OAuth(access_token, access_token_secret,
                    consumer_key, consumer_secret))

This is the traceback:

Traceback (most recent call last):
  File "search_twitter_entities.py", line 166, in <module>
    tw_endpoint.statuses.user_timeline, KW)
  File "/home/tg/mild/twitter_utils.py", line 171, in twitter_request
    return twitter_function(**args)
  File "build/bdist.linux-x86_64/egg/twitter/api.py", line 173, in __call__
  File "build/bdist.linux-x86_64/egg/twitter/api.py", line 177, in _handle_response
  File "/usr/lib/python2.7/urllib2.py", line 126, in urlopen
    return _opener.open(url, data, timeout)
  File "/usr/lib/python2.7/urllib2.py", line 400, in open
    response = self._open(req, data)
  File "/usr/lib/python2.7/urllib2.py", line 418, in _open
    '_open', req)
  File "/usr/lib/python2.7/urllib2.py", line 378, in _call_chain
    result = func(*args)
  File "/usr/lib/python2.7/urllib2.py", line 1215, in https_open
    return self.do_open(httplib.HTTPSConnection, req)
  File "/usr/lib/python2.7/urllib2.py", line 1180, in do_open
    r = h.getresponse(buffering=True)
  File "/usr/lib/python2.7/httplib.py", line 1030, in getresponse
    response.begin()
  File "/usr/lib/python2.7/httplib.py", line 407, in begin
    version, status, reason = self._read_status()
  File "/usr/lib/python2.7/httplib.py", line 371, in _read_status
    raise BadStatusLine(line)
httplib.BadStatusLine: ''

The only thing I can gain from that traceback is that the error happens somewhere deep inside another Python library and has something to do with an invalid HTTP stat coming from the Twitter API or the wrapper... But as I said, maybe some of you could give me a hint on how to debug/solve this since it is pretty annoying having to regularly check my script and restart it to continue fetching tweets.

EDIT: To clarify this a little, the first two functions in the traceback are already in a try-except block. For example, the try-except-Block in File "twitter_utils.py" filters out 40x and 50x exceptions, but also looks for general exceptions with only except:. So what I don't understand is why the error is not getting caught at this position and instead, the program is force-closed and a traceback printed? Shortly speaking I am in the situation where I cannot catch an error, just like a parse error in a PHP script. So how would I do this?

4

1 回答 1

0

也许这将为您指明正确的方向。这是调用 BadStatusLine 时调用的内容：

class BadStatusLine(HTTPException):
    def __init__(self, line):
        if not line:
            line = repr(line)
        self.args = line,
        self.line = line

我对 httplib 不太熟悉，但如果我不得不猜测，你会得到一个空的响应/错误行，而且，它无法被解析。在您的程序停止的行之前有注释：

    # Presumably, the server closed the connection before
    # sending a valid response.
    raise BadStatusLine(line)

如果 twitter 在发送响应之前关闭连接，您可以再试一次，这意味着在“search_twitter_entities.py”第 166 行尝试/除几次（丑陋）。

try:
     timeline = tw.twitter_request(tw_endpoint,\
              tw_endpoint.statuses.user_timeline, KW)
except:
     try:
          timeline = tw.twitter_request(tw_endpoint,\
                   tw_endpoint.statuses.user_timeline, KW) # try again
     except:
          pass

或者，假设您每次都可以将时间线重新分配为无，请执行一个 while 循环：

timeline = None
while timeline == None:
     try:
          timeline = tw.twitter_request(tw_endpoint,\
              tw_endpoint.statuses.user_timeline, KW)
     except:
          pass

我没有对此进行测试。检查错误代码。

于 2013-01-25T04:20:44.027 回答