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authorGeorg Brandl <georg@python.org>2010-07-31 18:09:23 (GMT)
committerGeorg Brandl <georg@python.org>2010-07-31 18:09:23 (GMT)
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@@ -37,6 +37,57 @@ The :mod:`functools` module defines the following functions:
.. versionadded:: 3.2
+.. decorator:: lfu_cache(maxsize)
+
+ Decorator to wrap a function with a memoizing callable that saves up to the
+ *maxsize* most frequent calls. It can save time when an expensive or I/O
+ bound function is periodically called with the same arguments.
+
+ The *maxsize* parameter defaults to 100. Since a dictionary is used to cache
+ results, the positional and keyword arguments to the function must be
+ hashable.
+
+ The wrapped function is instrumented with two attributes, :attr:`hits`
+ and :attr:`misses` which count the number of successful or unsuccessful
+ cache lookups. These statistics are helpful for tuning the *maxsize*
+ parameter and for measuring the cache's effectiveness.
+
+ The wrapped function also has a :attr:`clear` attribute which can be
+ called (with no arguments) to clear the cache.
+
+ A `LFU (least frequently used) cache
+ <http://en.wikipedia.org/wiki/Cache_algorithms#Least-Frequently_Used>`_
+ is indicated when the pattern of calls does not change over time, when
+ more the most common calls already seen are the best predictors of the
+ most common upcoming calls.
+
+ .. versionadded:: 3.2
+
+.. decorator:: lru_cache(maxsize)
+
+ 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
+ function is periodically called with the same arguments.
+
+ The *maxsize* parameter defaults to 100. Since a dictionary is used to cache
+ results, the positional and keyword arguments to the function must be
+ hashable.
+
+ The wrapped function is instrumented with two attributes, :attr:`hits`
+ and :attr:`misses` which count the number of successful or unsuccessful
+ cache lookups. These statistics are helpful for tuning the *maxsize*
+ parameter and for measuring the cache's effectiveness.
+
+ The wrapped function also has a :attr:`clear` attribute which can be
+ called (with no arguments) to clear the cache.
+
+ A `LRU (least recently used) cache
+ <http://en.wikipedia.org/wiki/Cache_algorithms#Least_Recently_Used>`_
+ is indicated when the pattern of calls changes over time, such as
+ when more recent calls are the best predictors of upcoming calls.
+
+ .. versionadded:: 3.2
+
.. decorator:: total_ordering
Given a class defining one or more rich comparison ordering methods, this