Python filtered tweets

"""
README:

Matthew Russell, January 25, 2016

requires tweepy
    (pip3 install tweepy)

Utilizing the tweepy module, this grabs all tweets from an account, filters
the found tweets using a user defined function, and saves them to a CSV file.

save_file: the filename to save to
target_username: the target account
nitain_filter: the filter function used to filter nitain tweets
"""

import json

# https://github.com/tweepy/tweepy
# for more info, http://docs.tweepy.org/en/latest/api.html
import tweepy


# Variables that contains the user credentials to access Twitter API
# Get your own from https://apps.twitter.com/
ACCESS_TOKEN = 'get your'
ACCESS_SECRET = 'own damn'
CONSUMER_KEY = 'access keys'
CONSUMER_SECRET = 'and tokens'

save_file = 'nitain_tweets.csv'
target_username = 'warframealerts'


def nitain_filter(tweet):
    """
    edit this to determine how tweets are filtered
    """
    if 'nitain' in tweet.text.lower():
        return True
    return False

def get_all_tweets(screen_name, chunk_size=200):
    """
    returns all tweets from screen_name and that pass the filter_ check
    You may also specify the number of chunks requested per tweepy call.

    Twitter only allows access to a users most recent 3240 tweets with this
    method

    If chunk size is greater than 200, only 200 tweets are returned
    """

    #authorize twitter, initialize tweepy
    auth = tweepy.OAuthHandler(CONSUMER_KEY, CONSUMER_SECRET)
    auth.set_access_token(ACCESS_TOKEN, ACCESS_SECRET)
    api = tweepy.API(auth)

    oldest_id = None  # id of the oldest tweet
    new_tweets = []
    downloaded_tweets = []

    # keep grabbing tweets until there are no tweets left to grab
    while True:
        if oldest_id is None:
            print("Requesting the first %i tweets" % (chunk_size))

            new_tweets = api.user_timeline(
                screen_name = screen_name,
                count=chunk_size
            )
        else:
            print("Requesting %i tweets before id %s" % (chunk_size, oldest_id))

            # all subsiquent requests use the max_id param to prevent
            # duplicates
            new_tweets = api.user_timeline(
                screen_name = screen_name,
                count=chunk_size,
                max_id=oldest_id
            )

        if not new_tweets:
            print("Found all %i tweets" % len(downloaded_tweets))
            break

        downloaded_tweets += new_tweets

        # update the id of the oldest tweet minus one, as this prevents
        # grabbing the same or newer tweets (that have larger id vals)
        oldest_id = new_tweets[-1].id - 1
    return downloaded_tweets


if __name__ == '__main__':
    # pass in the username of the account you want to download
    tweets = get_all_tweets(target_username)

    # filter tweets
    tweets = [a for a in tweets if nitain_filter(a)]

    print("Found %i filtered tweets" % len(tweets))

    with open(save_file, 'w') as f:
        """# use this instead ofr human readable
        f.write('%s,%s,%s\n'%("id","created on","text"))

        for a in tweets:
            f.write('%s\n'%(','.join([a.id_str, str(a.created_at), a.text])))
        """

        # use this for quick date formatting
        f.write('%s,%s\n'%("date","time"))

        for a in tweets:
            f.write('%s\n'%(str(a.created_at).replace(' ', ',', 1)))