find the delta between 2 lists in python

list delta.py

import time
import string
import random

def print_timing(func):
    def wrapper(*arg):
        t1 = time.time()
        res = func(*arg)
        t2 = time.time()
        print '%s took %0.3f ms' % (func.func_name, (t2-t1)*1000.0)
        return res
    return wrapper

@print_timing
def findDelta1(today,yesterday):
     results = {}
     ypos = 0
     for i,title in enumerate(today):
          if title in results:
               results[title] = results[title] - i
          else:
               for ypos in xrange(ypos,len(yesterday)):
                    if yesterday[ypos] == title:
                         results[title] = ypos - i
                         ypos = ypos + 1
                         break
                    else:
                         results[yesterday[ypos]] = ypos
     return results

@print_timing
def findDelta2(today,yesterday):
     D = dict((k,v) for v,k in enumerate(yesterday))
     return dict((k,D[k]-v) for v,k in enumerate(today))

class LookupOnce:
    def __init__(self, seq):
        self.cache = {}
        self.seq = iter(seq)
    def get(self, key):
        if key in self.cache:
            value = self.cache[key]
            del self.cache[key]
            return value
        for v,k in self.seq:
            if k == key:
                return v
            self.cache[k] = v
        raise KeyError

@print_timing
def findDelta3(a, b):
    rank_a = LookupOnce(enumerate(a))
    rank_b = enumerate(b)
    result = {}
    for i, k in rank_b:
        result[k] = i - rank_a.get(k)
    return result


def createRandomString(l):
     return "".join([random.choice(string.letters) for x in xrange(l)])
def createRandomList(l,sl):
     return [createRandomString(sl) for x in xrange(l)];

def agitateList(l):
     r = l
     random.shuffle(r,random.random)
     return r

random.seed(99)

today = createRandomList(100000,20)
#today = createRandomList(10,10)

print 'no change'
yesterday = today
findDelta1(today,yesterday)
findDelta2(today,yesterday)
findDelta3(today,yesterday)

print 'fully shuffled'
yesterday = today[:]
random.shuffle(yesterday)
findDelta1(today,yesterday)
findDelta2(today,yesterday)
findDelta3(today,yesterday)

# a random resultset on my system. run for yourself.
# no change
# findDelta1 took 339.984 ms
# findDelta2 took 803.962 ms
# findDelta3 took 563.973 ms
# fully shuffled
# findDelta1 took 479.977 ms
# findDelta2 took 1047.950 ms
# findDelta3 took 467.977 ms