api = tw_oauth('./auth.k')
coursor = tweepy.Cursor(api.search, q='site.ru',  count = 20)
for tweet in coursor.items():
   ...

def limit_handled(cursor):
    while True:
        try:
            yield cursor.next()
        except tweepy.RateLimitError:
            time.sleep(15 * 60)

for tweet in limit_handled(tweepy.Cursor(api.search, q='site.ru', count = 20).items()):
    print (tweet.id)