Deobfuscate Hulu ajax responses in Python

gistfile1.py

"""
I'm a python port of Hulu's javascript for deobfuscating certain ajax responses.
As of 2009-April-05, I've been tested on Python 2.5.2.

A usage example that relies on BeautifulSoup (http://bit.ly/3Ks24u):

import urllib
from BeautifulSoup import BeautifulSoup
url = "http://www.hulu.com/channels/Drama/?kind=videos&sort=rating&type=tv"
text = urllib.urlopen(url).read()
soup = BeautifulSoup(_dobfu(text))
for inc in soup(attrs={"class":"show-title-container"}):
    print "".join([inc.a.contents[0],inc.a.span.contents[0]])

"""

import math, re, urllib

# srzf is bitwise shift right (zero fill)
# It shifts n right by b bits and is equiv to >>> in js
def srzf(n, b):
    return (n & 0xFFFFFFFFL) >> b

# tol returns a list of numeric longs; maybe tol means "to long"
def tol(s):
    return map(lambda i: ord(s[i*4]) + (ord(s[i*4+1]) << 8) + (ord(s[i*4+2]) << 16) + (ord(s[i*4+3]) << 24), range(0,math.ceil(len(s) / 4 -1)))

# _dobfu deobfuscates ajax responses for various pages from Hulu
# And it returns a single string of html, js, css
def _dobfu(text):
    return re.sub('\\0+$','',"".join(map(lambda i: (lambda i = 0xfeedface ^ i: chr(i & 0xFF) + chr(srzf(i,8) & 0xFF) + chr(srzf(i,16) & 0xFF) + chr(srzf(i,24) & 0xFF)) (),tol(urllib.unquote(text[7:]))))) if text[0:7] == "dobfu__" else text