euler.py

#! /usr/bin/env python
import heapq
from itertools import imap, ifilter
import time
before = time.time()

class Pair(object):
    def __init__(self, f1, f2):
        self.f1, self.f2 = f1, f2
        self.total = f1 + f2
    def __eq__(self, other):
        return self.total == other.total
    def __lt__(self, other):
        return self.total > other.total    
    def __le__(self, other):
        return self.total >= other.total

def pair_with(elem, it):
    return (Pair(elem,el) for el in it)



pairs_generators = [pair_with(n, xrange(n,100,-1)) for n in xrange(999,100,-1)]

sorted_combs = heapq.merge(*pairs_generators)

products = imap(lambda p: p.f1 * p.f2, sorted_combs)
palindrome_products = ifilter(lambda n : n == ''.join(reversed(n)), imap(str,products))

print next(palindrome_products)

print time.time()-before