Error Handling

Besides tweet statuses, the REST API and Streaming API iterators may return error and other messages. It is up to the application to test what type of object has been returned. Message types are documented here and here.

REST API Messages

REST API endpoints can return many more types of messages than Streaming API endpoints. Depending on the endpoint, you may want to handle a particular type of message, such as exceeding a rate limit or posting a duplicate tweet. Here is a general pattern for simply printing out any message and error code:

r = api.request('search/tweets', {'q':'pizza'})
for item in r.get_iterator():
    if 'text' in item:
        print item['text']
    elif 'message' in item:
        print '%s (%d)' % (item['message'], item['code'])

Streaming API Messages

Streaming API endpoints return a variety of messages, most are not really errors. For example, a “limit” message contains the number of tweets missing from the stream. This happens when the number of tweets matching your filter exceeds a threshold set by Twitter. Other useful messages are “disconnect” and “delete”. The pattern is similar to the one preceding:

r = api.request('statuses/filter', {'track':'pizza'})
for item in r.get_iterator():
    if 'text' in item:
        print item['text']
    elif 'limit' in item:
        print '%d tweets missed' % item['limit']['track']
    elif 'disconnect' in item:
        print 'disconnecting because %s' % item['disconnect']['reason']
        break

Even if you are not interested in handling errors it is necessary to test that the object returned by an iterator is a valid tweet status before using the object.