Django spam filter moderator with StopForumSpam service check

moderator.py

import urllib, urllib2
import xml.dom import minidom

from django.contrib.comments.moderation import CommentModerator

SFS_API_URL = 'http://www.stopforumspam.com/api?'


def is_spam(ip, email):
	"""
	Check if IP and email is listed at StopForumSpam blacklist
	"""

	ip_blacklist = email_blacklist = False
	data = urllib.urlencode({ 'ip': ip, 'email': email })

	try:
		response = urllib2.urlopen(SFS_API_URL + data)
	except urllib2.HTTPError as e:
		response = False
	
	if response:
		dom = minidom.parse(response)
		ip_blacklist = dom.getElementsByTagName('appears')[0].childNodes[0].data == 'yes'
		email_blacklist = dom.getElementsByTagName('appears')[1].childNodes[0].data == 'yes'
	
	return ip_blacklist or email_blacklist


class SFSModerator(CommentModerator):
	def moderate(self, comment, content_object, request):
		"""Moderate (change is_public) if ip or e-mail listed at StopForumSpam"""
		return is_spam(comment.ip_address, comment.user_email)