> I think the lru_cache should be kept if possible (i.e. I'm -0.5 on your patch). This patch is only to show the upper level to which should be sought. I tried to optimize lru_cache(), but got only 15%. I'm afraid that serious optimization is impossible without rewriting lru_cache() on C. > 2) avoid using it for regular expressions compiled with re.compile; I do not see how it can significantly affect performance.