On Fri, 1 May 2009 10:16:11 am George Sakkis wrote:
IMHO no existing implementation is good enough for addition to the standard library. Off the top of my head, some of the issues a general and robust implementation should address are: - Non hashable parameters. - Caching keys based on a subset of the provided parameters (or perhaps more general a key function). - Bounded-length caches. - Different expiration policies for bounded-length caches. - As good performance as possible given the previous constraints.
Of course one can write a vanilla version in a few lines, and indeed searching for "memoize" in code.activestate.com returns no less than 125 results (including one I posted 4.5 years ago). I think the sheer number of the posted recipes is an indication that none of them has "solved" the problem for good, otherwise people would just reuse it instead of keep posting alternatives.
Or people just like re-inventing the wheel. By all means go ahead and write a PEP and develop an heavyweight "deal with everything including the kitchen sink" solution. But in the meantime, the standard library could do with a couple of nice, simple, lightweight memoize decorators. -- Steven D'Aprano