How to convert links to TinyURLs

import re
import urllib

links_re = re.compile('http://[^\s]+')

def convert_links(text):
    def converter(m):
        link = m.group(0)
        if len(link) <= 30:
            return link
        else:
            params = urllib.urlencode({'url': link})
            fp = urllib.urlopen("http://tinyurl.com/api-create.php", params)
            return fp.read()
    return re.sub(links_re, converter, text)

print convert_links("This is a test http://amix.dk/blog/viewEntry/19398")
#prints "This is a test http://tinyurl.com/djdy24"