from random import randint s1 = '' s2 = ''
for i in xrange(1000): s1 += chr(randint(97,122)) s2 += chr(randint(97,122)) print s1[:25] print s2[:25] import difflib s = difflib.SequenceMatcher(None, s1, s2) print s.find_longest_match(0, len(s1), 0, len(s2)) >>> ============== RESTART ==================== >>> yymgzldocfaafcborxbpqyade urvwtnkwfmcduybjqmrleflqx (0, 0, 0) >>> I think it's line #314 in difflib "who's to blame" -- -- http://mail.python.org/mailman/listinfo/python-list