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| -rw-r--r-- | Doc/library/functools.rst | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/Doc/library/functools.rst b/Doc/library/functools.rst index e981bcd..871c94a 100644 --- a/Doc/library/functools.rst +++ b/Doc/library/functools.rst @@ -154,15 +154,16 @@ The :mod:`functools` module defines the following functions: @lru_cache def count_vowels(sentence): - sentence = sentence.casefold() - return sum(sentence.count(vowel) for vowel in 'aeiou') + return sum(sentence.count(vowel) for vowel in 'AEIOUaeiou') If *maxsize* is set to ``None``, the LRU feature is disabled and the cache can grow without bound. 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. + cached separately. For example, ``f(3)`` and ``f(3.0)`` will always be + treated as distinct calls with distinct results. If *typed* is false, + the implementation will usually but not always regard them as equivalent + calls and only cache a single result. The wrapped function is instrumented with a :func:`cache_parameters` function that returns a new :class:`dict` showing the values for *maxsize* @@ -172,8 +173,7 @@ The :mod:`functools` module defines the following functions: To help measure the effectiveness of the cache and tune the *maxsize* parameter, the wrapped function is instrumented with a :func:`cache_info` function that returns a :term:`named tuple` showing *hits*, *misses*, - *maxsize* and *currsize*. In a multi-threaded environment, the hits - and misses are approximate. + *maxsize* and *currsize*. The decorator also provides a :func:`cache_clear` function for clearing or invalidating the cache. @@ -182,6 +182,9 @@ The :mod:`functools` module defines the following functions: :attr:`__wrapped__` attribute. This is useful for introspection, for bypassing the cache, or for rewrapping the function with a different cache. + The cache keeps references to the arguments and return values until they age + out of the cache or until the cache is cleared. + An `LRU (least recently used) cache <https://en.wikipedia.org/wiki/Cache_replacement_policies#Least_recently_used_(LRU)>`_ works best when the most recent calls are the best predictors of upcoming |