can't get urllib2 or httplib to work with tor & privoxy

[Bob Fnord]

Here's my python code:

import httplib, urllib2

proxy_handler = {'http' : 'localhost:8118',
                 'https' : 'localhost:8118'}

def connect_u2(url = 'http://ipid.shat.net/iponly/'):,
    proxied = urllib2.ProxyHandler(proxy_handler)
    opnr = urllib2.build_opener(proxied)
    opnr.addheaders = [('User-agent', agent)]
    rsp = opnr.open(url)
    page = rsp.read()
    return page

def connect_h(url = 'http://ipid.shat.net/iponly/'):
    cnn = httplib.HTTPConnection('127.0.0.1', 8118)
    cnn.connect()
    cnn.request('GET', url)
    rsp = cnn.getresponse()
    stderr.write('%u %s\n' % (rsp.status, rsp.reason))
    page = rsp.read(500)
    cnn.close()
    return page

Both methods give me a 503 error, even though this

export http_proxy='http://localhost:8118/'
lynx -dump 'http://ipid.shat.net/iponly/'

works in bash and prints out the IP of a tor exit.

What am I doing wrong in python?  (I tried both 'localhost:8118' and
'http://localhost:8118/' in the proxy_handler dict.)