On Monday, July 31, 2017 at 7:31:52 PM UTC-4, t...@tomforb.es wrote: > As part of the Python 3 cleanup in Django there are a fair few uses of > @functools.lru_cache on functions that take no arguments. A lru_cache isn't > strictly needed here, but it's convenient to just cache the result. Some > examples are here: https://github.com/django/django/pull/8825/files > > I did some profiling and I found that using `@lru_cache(maxsize=None)` on > such functions is twice as fast as a standard `@lru_cache()`, apparently > because with a `maxsize` the lru_cache code requires a lock acquisition and a > fair bit more state to track. > > Am I right in thinking that using `maxsize=None` is best for functions that > accept no arguments? Should we even be using a `lru_cache` in such > situations, or write our own simple cache decorator instead?
If the performance savings are real, another choice would be to improve the implementation of lru_cache to special-case no-argument functions to avoid locks, etc. -- https://mail.python.org/mailman/listinfo/python-list
