The wrapper functions themselves, though, exist in a one:one
correspondence with the functions they're applied to - when you apply functools.lru_cache to a function, the transient decorator produced by the decorator factory only lasts as long as the execution of the function definition, but the wrapper function lasts for as long as the wrapped function does, and gets invoked every time that function is called (and if a function is performance critical enough for the results to be worth caching, then it's likely performance critical enough to be thinking about micro-optimisations). (Nick Coghlan)
Yes, that is what I was thinking of. Just like Quake's fast inverse square root. Even though it is a micro-optimization, it greatly affects how fast the game runs. But, as I explained, the function will _not_ be redefined and trashed every
frame; it will be created one time. (Andrew Barnert)
Hmm... Nick says different... This all suggests that if your application is severely memory
constrained (e.g. it's running on an embedded interpreter like MicroPython), then it *might* make sense to incur the extra complexity of using classes with a custom __call__ method to define wrapper functions, over just using a nested function. (Nick Coghlan)
Yes, I was thinking of that when I started this thread, but this thread is just from my speculation. -- -Surya Subbarao