http://projecteuler.net/problem=4 A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 × 99. Find the largest palindrome made from the product of two 3-digit numbers.

palindrome_detector.py

# Copyright 2013, Alex Ausch 
# Free to use under attribution license: http://creativecommons.org/licenses/by/2.0/ca/

def is_palindrome(num):
    palindrome = str(num)
    return palindrome == palindrome[::-1]

def fn(n):
    max_palindrome = 1
    for x in range(n,1,-1):
        if x*n < max_palindrome:
            break
        for y in range(n,x-1,-1):
            if is_palindrome(x*y) and x*y > max_palindrome:
                max_palindrome = x*y
            elif x * y < max_palindrome:
                break
    return max_palindrome

print fn(999)