Avoid Twitter API limitation with Tweepy

问题:

I saw in some question on Stack Exchange that the limitation can be a function of the number of requests per 15 minutes and depends also on the complexity of the algorithm, except that this is not a complex one.

So I use this code:

import tweepy
import sqlite3
import time

db = sqlite3.connect('data/MyDB.db')

# Get a cursor object
cursor = db.cursor()
cursor.execute('''CREATE TABLE IF NOT EXISTS MyTable(id INTEGER PRIMARY KEY, name TEXT, geo TEXT, image TEXT, source TEXT, timestamp TEXT, text TEXT, rt INTEGER)''')
db.commit()

consumer_key = ""
consumer_secret = ""
key = ""
secret = ""

auth = tweepy.OAuthHandler(consumer_key, consumer_secret)
auth.set_access_token(key, secret)

api = tweepy.API(auth)

search = "#MyHashtag"

for tweet in tweepy.Cursor(api.search,
                           q=search,
                           include_entities=True).items():
    while True:
        try:
            cursor.execute('''INSERT INTO MyTable(name, geo, image, source, timestamp, text, rt) VALUES(?,?,?,?,?,?,?)''',(tweet.user.screen_name, str(tweet.geo), tweet.user.profile_image_url, tweet.source, tweet.created_at, tweet.text, tweet.retweet_count))
        except tweepy.TweepError:
                time.sleep(60 * 15)
                continue
        break
db.commit()
db.close()

I always get the Twitter limitation error:

Traceback (most recent call last):
  File "stream.py", line 25, in <module>
    include_entities=True).items():
  File "/usr/local/lib/python2.7/dist-packages/tweepy/cursor.py", line 153, in next
    self.current_page = self.page_iterator.next()
  File "/usr/local/lib/python2.7/dist-packages/tweepy/cursor.py", line 98, in next
    data = self.method(max_id = max_id, *self.args, **self.kargs)
  File "/usr/local/lib/python2.7/dist-packages/tweepy/binder.py", line 200, in _call
    return method.execute()
  File "/usr/local/lib/python2.7/dist-packages/tweepy/binder.py", line 176, in execute
    raise TweepError(error_msg, resp)
tweepy.error.TweepError: [{'message': 'Rate limit exceeded', 'code': 88}]

回答1:

The problem is that your try: except: block is in the wrong place. Inserting data into the database will never raise a TweepError - it's iterating over Cursor.items() that will. I would suggest refactoring your code to call the next method of Cursor.items() in an infinite loop. That call should be placed in the try: except: block, as it can raise an error.

Here's (roughly) what the code should look like:

# above omitted for brevity
c = tweepy.Cursor(api.search,
                       q=search,
                       include_entities=True).items()
while True:
    try:
        tweet = c.next()
        # Insert into db
    except tweepy.TweepError:
        time.sleep(60 * 15)
        continue
    except StopIteration:
        break

This works because when Tweepy raises a TweepError, it hasn't updated any of the cursor data. The next time it makes the request, it will use the same parameters as the request which triggered the rate limit, effectively repeating it until it goes though.

回答2:

For anyone who stumbles upon this on Google, tweepy 3.2+ has additional parameters for the tweepy.api class, in particular:

• wait_on_rate_limit – Whether or not to automatically wait for rate limits to replenish
• wait_on_rate_limit_notify – Whether or not to print a notification when Tweepy is waiting for rate limits to replenish

Setting these flags to True will delegate the waiting to the API instance, which is good enough for most simple use cases.

回答3:

If you want to avoid errors and respect the rate limit you can use the following function which takes your api object as an argument. It retrieves the number of remaining requests of the same type as the last request and waits until the rate limit has been reset if desired.

def test_rate_limit(api, wait=True, buffer=.1):
    """
    Tests whether the rate limit of the last request has been reached.
    :param api: The `tweepy` api instance.
    :param wait: A flag indicating whether to wait for the rate limit reset
                 if the rate limit has been reached.
    :param buffer: A buffer time in seconds that is added on to the waiting
                   time as an extra safety margin.
    :return: True if it is ok to proceed with the next request. False otherwise.
    """
    #Get the number of remaining requests
    remaining = int(api.last_response.getheader('x-rate-limit-remaining'))
    #Check if we have reached the limit
    if remaining == 0:
        limit = int(api.last_response.getheader('x-rate-limit-limit'))
        reset = int(api.last_response.getheader('x-rate-limit-reset'))
        #Parse the UTC time
        reset = datetime.fromtimestamp(reset)
        #Let the user know we have reached the rate limit
        print "0 of {} requests remaining until {}.".format(limit, reset)

        if wait:
            #Determine the delay and sleep
            delay = (reset - datetime.now()).total_seconds() + buffer
            print "Sleeping for {}s...".format(delay)
            sleep(delay)
            #We have waited for the rate limit reset. OK to proceed.
            return True
        else:
            #We have reached the rate limit. The user needs to handle the rate limit manually.
            return False 

    #We have not reached the rate limit
    return True

回答4:

Just replace

api = tweepy.API(auth)

with

api = tweepy.API(auth, wait_on_rate_limit=True)