Joins a piece of text with a url to form max length tweet

join_text_url.py

long_tweet = 'asdfasdf asd fasd fasdf asdf asdf asdf asdf asdf asdf asdf asdf asdf asdf asdf asdf asdf asdf asdfasdf asdfasdfas dfasd fasd fasdf asdf asdf asdf asdf asdf asdf '
short_tweet = 'asdfasdf asd fasd fasdf asdf asdf asdf asdf asdf asdf asdf asdf'

url = "http://sia.tw/4fgs4"


def join_url(tweet, url):
    max_tweet_length = 139

    if url:
        max_tweet_length = max_tweet_length - len(url)
    
    if len(tweet) > max_tweet_length:
        tweet = tweet[0:max_tweet_length - 4].strip() + "... " + url
    else:
        tweet = tweet + " " + url
        
    return tweet
    
joined = join_url(long_tweet, url)
print joined
print len(joined)

joined = join_url(short_tweet, url)
print joined
print len(joined)