如何干燥处理Twitter API速率限制

Question

I have the following code pattern to handle various exceptions that arise while accessing Twitter API. The basic pattern is:

while True:
    try:
        # 'access twitter api'
    except tweepy.error.TweepError:
        # 'handling the error'

I have multiple methods, eg get_tweets() , get_friends() , all of which use the same error handling pattern. How to DRY this?

For example, below is my get_tweets() method. How to re-use the error handling in this method in others?

def get_tweets(self, screen_name):        
    while True:
        try:
            rs = self.api.user_timeline(screen_name=screen_name)

        except tweepy.error.TweepError, e:
            if e.response.status_code == 404:
                print "%s does not exist" % (twitter_id)
                return None

            elif e.response.status_code == 429:
                print "out of quota"
                time.sleep(60 * 15)
                continue

            elif e.response.status_code == 503:
                print "Twitter down"
                time.sleep(60 * 15)
                continue

            else:
                print "%s, %s" % (twitter_id, e)
                continue

Answer 1

If the contents of the except statement is repeated multiple places it might a good candidate for some reuse.

I see multiple ways you might do this, here are some options.

1. Define an error handler that can be used by multiple methods:

def get_tweets(self, screen_name):
    while True:
        try:
            rs = self.api.user_timeline(screen_name=screen_name)
        except tweepy.error.TweepError, e:
            error_handler(e)

def error_handler(self, e):
    # handle the error

Of course with this option we end up repeating

while True:
    try:
        # access twitter api
    except:
        # handle error

2. Instead you can create a general twitter call function which accepts a method and some arguments for the method.

def twitter_request(self, twitter_method, *args, **kwargs):
    while True:
        try:
            twitter_method(*args, **kwargs)
        except tweepy.error.TweepError, e:
            # handle the error

def get_tweets(self, screen_name):
    twitter_request(self.api.user_timeline, screen_name=screen_name)

These options can also be combined if you need the ability to replace the error handling function for some api calls by adding the error handler function as argument to twitter_request