From: Raymond Hettinger Date: Mon, 26 Nov 2018 00:24:52 +0000 (-0800) Subject: bpo-35300: Add usage note to the lru_cache() docs (GH-10707) X-Git-Tag: v3.8.0a1~431 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=f0e0f2008d160cdd7e5bc02ea61c43f8c7b2b82f;p=python bpo-35300: Add usage note to the lru_cache() docs (GH-10707) https://bugs.python.org/issue35300 --- diff --git a/Doc/library/functools.rst b/Doc/library/functools.rst index 40abdc2488..cd59e5bebf 100644 --- a/Doc/library/functools.rst +++ b/Doc/library/functools.rst @@ -118,6 +118,11 @@ The :mod:`functools` module defines the following functions: The cache's size limit assures that the cache does not grow without bound on long-running processes such as web servers. + In general, the LRU cache should only be used when you want to reuse + previously computed values. Accordingly, it doesn't make sense to cache + functions with side-effects, functions that need to create distinct mutable + objects on each call, or impure functions such as time() or random(). + Example of an LRU cache for static web content:: @lru_cache(maxsize=32)