gistfile1.py

class VoteHandler(webapp.RequestHandler):
            
    def get(self):
        
        #See if logged in
        self.Session = Session()
        if not 'userkey' in self.Session:
            doRender(
                self,
                '/loginscreen.html',
                {'error' : 'Please login'})
            return
        user = self.Session['userkey']
        
        #pull in the Image id
        imagekey = self.request.get('photo_id') 
        vurl = models.Image.get_by_id(int(imagekey))
        photo_key = vurl.key()
        
        #check existing votes for one by user
        existing_vote = models.Vote.all().filter('user = ', user).filter('photo = ',photo_key).count()
        
        if existing_vote != 0:
            self.redirect('/', { })
        else:    
            
            #Add 1 to total votes on Image
            vurl.votes += 1
            vurl.put()
  
            #Create a new Vote object
            newvote = models.Vote(user = user, photo = vurl)
            newvote.put()    
            self.redirect('/', { })