diff options
Diffstat (limited to 'Doc/library/functools.rst')
| -rw-r--r-- | Doc/library/functools.rst | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/Doc/library/functools.rst b/Doc/library/functools.rst index 04743d31fa..f5c6608e1d 100644 --- a/Doc/library/functools.rst +++ b/Doc/library/functools.rst @@ -40,7 +40,7 @@ The :mod:`functools` module defines the following functions: .. versionadded:: 3.2 -.. decorator:: lru_cache(maxsize=100) +.. decorator:: lru_cache(maxsize=128, typed=False) Decorator to wrap a function with a memoizing callable that saves up to the *maxsize* most recent calls. It can save time when an expensive or I/O bound @@ -49,8 +49,13 @@ The :mod:`functools` module defines the following functions: Since a dictionary is used to cache results, the positional and keyword arguments to the function must be hashable. - If *maxsize* is set to None, the LRU feature is disabled and the cache - can grow without bound. + If *maxsize* is set to None, the LRU feature is disabled and the cache can + grow without bound. The LRU feature performs best when *maxsize* is a + power-of-two. + + If *typed* is set to True, function arguments of different types will be + cached separately. For example, ``f(3)`` and ``f(3.0)`` will be treated + as distinct calls with distinct results. To help measure the effectiveness of the cache and tune the *maxsize* parameter, the wrapped function is instrumented with a :func:`cache_info` @@ -67,8 +72,8 @@ The :mod:`functools` module defines the following functions: An `LRU (least recently used) cache <http://en.wikipedia.org/wiki/Cache_algorithms#Least_Recently_Used>`_ works - best when more recent calls are the best predictors of upcoming calls (for - example, the most popular articles on a news server tend to change daily). + best when the most recent calls are the best predictors of upcoming calls (for + example, the most popular articles on a news server tend to change each day). The cache's size limit assures that the cache does not grow without bound on long-running processes such as web servers. @@ -111,6 +116,9 @@ The :mod:`functools` module defines the following functions: .. versionadded:: 3.2 + .. versionchanged:: 3.3 + Added the *typed* option. + .. decorator:: total_ordering Given a class defining one or more rich comparison ordering methods, this |