URLshortener.py

#URLshortener
#  this class POSTs to http://ur1.ca and then gets the 
#  returned shortened UR1 from the repsonse
#
#this requires requests and only works with python2
# https://pypi.python.org/pypi/requests/0.13.0
import requests

class URLshortener(object):
    def __init__(self):
        print("init object")
        
    def getURLfromUR1caResponse(self, response):
        #response:
        #...
        #<p class="success">Your ur1 is: <a href="http://ur1.ca/hzm8a">http://ur1.ca/hzm8a</a></p>
        #...
        prefx       = '<p class="success">Your ur1 is: <a href="'
        linkClose   = '">'
        postfx      = '</a>'

        if not prefx in response:
            return "failure"    

        pos = 0        
        pos = response.find(prefx,pos)
        if pos < 0:
            return "failure"
            
        htmlText = response[pos:response.find(postfx,pos) + len(postfx)]
        #print "htmlText:" + htmlText
        
        link = htmlText[htmlText.find(prefx)+len(prefx):]
        link = link[:link.find(linkClose)]
        print "link: " + link
        linkmsg = htmlText[htmlText.find(linkClose)+len(linkClose):htmlText.find(postfx)]
        #print "linkmsg: " + linkmsg
        
        return link

    def getUR1ca(self, longurl):
        payload = {'longurl':longurl}
        r = requests.post('http://ur1.ca', data=payload)
        
        print "original URL length: " + str(len(longurl))
        shortURL = self.getURLfromUR1caResponse(r.text)
        print "short URL length: " + str(len(shortURL))
        
        if len(longurl) <= len(shortURL):
            return longurl
        else:
            return shortURL
        
if __name__ == '__main__':
    import sys
    myurl = URLshortener()
    print myurl.getUR1ca(sys.argv[1])