Caching is really useful, right?

This decorator cached_factory looks really useful, doesn’t it? It is pretty flexible and it can save you a tremendous amount of time in function calls… And that is why it’s actually in the standard library!

The module functools contains two caching decorators:

• cache, similar to what you’ve been developing and improving so far; and

• lru_cache, a cache decorator with a built-in system to manage the cache size.

The decorators from the module functools are even better than the one you’ve developed so far because the decorator cached_factory still has some limitations that functools.cache and functools.lru_cache do not have. You will understand these limitations, and get rid of them, progressively as you keep working through this course.