Author: georg.brandl Date: Sat Jul 31 12:16:21 2010 New Revision: 83329 Log: Revert r83327. This will have to wait until after the alpha1 release. Modified: python/branches/py3k/Doc/library/functools.rst python/branches/py3k/Lib/functools.py python/branches/py3k/Lib/test/test_functools.py python/branches/py3k/Misc/NEWS Modified: python/branches/py3k/Doc/library/functools.rst ============================================================================== --- python/branches/py3k/Doc/library/functools.rst (original) +++ python/branches/py3k/Doc/library/functools.rst Sat Jul 31 12:16:21 2010 @@ -37,57 +37,6 @@ .. 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 Modified: python/branches/py3k/Lib/functools.py ============================================================================== --- python/branches/py3k/Lib/functools.py (original) +++ python/branches/py3k/Lib/functools.py Sat Jul 31 12:16:21 2010 @@ -4,17 +4,10 @@ # to allow utilities written in Python to be added # to the functools module. # Written by Nick Coghlan <ncoghlan at gmail.com> -# and Raymond Hettinger <python at rcn.com> -# Copyright (C) 2006-2010 Python Software Foundation. +# Copyright (C) 2006 Python Software Foundation. # See C source code for _functools credits/copyright -__all__ = ['update_wrapper', 'wraps', 'WRAPPER_ASSIGNMENTS', 'WRAPPER_UPDATES', - 'total_ordering', 'cmp_to_key', 'lfu_cache', 'lru_cache'] - from _functools import partial, reduce -from collections import OrderedDict, Counter -from heapq import nsmallest -from operator import itemgetter # update_wrapper() and wraps() are tools to help write # wrapper functions that can handle naive introspection @@ -104,88 +97,3 @@ def __hash__(self): raise TypeError('hash not implemented') return K - -def lfu_cache(maxsize=100): - '''Least-frequently-used cache decorator. - - Arguments to the cached function must be hashable. - Cache performance statistics stored in f.hits and f.misses. - Clear the cache using f.clear(). - http://en.wikipedia.org/wiki/Cache_algorithms#Least-Frequently_Used - - ''' - def decorating_function(user_function): - cache = {} # mapping of args to results - use_count = Counter() # times each key has been accessed - kwd_mark = object() # separate positional and keyword args - - @wraps(user_function) - def wrapper(*args, **kwds): - key = args - if kwds: - key += (kwd_mark,) + tuple(sorted(kwds.items())) - use_count[key] += 1 # count a use of this key - try: - result = cache[key] - wrapper.hits += 1 - except KeyError: - result = user_function(*args, **kwds) - cache[key] = result - wrapper.misses += 1 - if len(cache) > maxsize: - # purge the 10% least frequently used entries - for key, _ in nsmallest(maxsize // 10, - use_count.items(), - key=itemgetter(1)): - del cache[key], use_count[key] - return result - - def clear(): - 'Clear the cache and cache statistics' - cache.clear() - use_count.clear() - wrapper.hits = wrapper.misses = 0 - - wrapper.hits = wrapper.misses = 0 - wrapper.clear = clear - return wrapper - return decorating_function - -def lru_cache(maxsize=100): - '''Least-recently-used cache decorator. - - Arguments to the cached function must be hashable. - Cache performance statistics stored in f.hits and f.misses. - Clear the cache using f.clear(). - http://en.wikipedia.org/wiki/Cache_algorithms#Least_Recently_Used - - ''' - def decorating_function(user_function): - cache = OrderedDict() # ordered least recent to most recent - kwd_mark = object() # separate positional and keyword args - - @wraps(user_function) - def wrapper(*args, **kwds): - key = args - if kwds: - key += (kwd_mark,) + tuple(sorted(kwds.items())) - try: - result = cache.pop(key) - wrapper.hits += 1 - except KeyError: - result = user_function(*args, **kwds) - wrapper.misses += 1 - if len(cache) >= maxsize: - cache.popitem(0) # purge least recently used cache entry - cache[key] = result # record recent use of this key - return result - - def clear(): - 'Clear the cache and cache statistics' - cache.clear() - wrapper.hits = wrapper.misses = 0 - - wrapper.hits = wrapper.misses = 0 - wrapper.clear = clear - return wrapper - return decorating_function Modified: python/branches/py3k/Lib/test/test_functools.py ============================================================================== --- python/branches/py3k/Lib/test/test_functools.py (original) +++ python/branches/py3k/Lib/test/test_functools.py Sat Jul 31 12:16:21 2010 @@ -4,7 +4,6 @@ from test import support from weakref import proxy import pickle -from random import choice @staticmethod def PythonPartial(func, *args, **keywords): @@ -455,50 +454,6 @@ class A: pass -class TestLRU(unittest.TestCase): - - def test_lru(self): - def orig(x, y): - return 3*x+y - f = functools.lru_cache(maxsize=20)(orig) - - domain = range(5) - for i in range(1000): - x, y = choice(domain), choice(domain) - actual = f(x, y) - expected = orig(x, y) - self.assertEquals(actual, expected) - self.assert_(f.hits > f.misses) - self.assertEquals(f.hits + f.misses, 1000) - - f.clear() # test clearing - self.assertEqual(f.hits, 0) - self.assertEqual(f.misses, 0) - f(x, y) - self.assertEqual(f.hits, 0) - self.assertEqual(f.misses, 1) - - def test_lfu(self): - def orig(x, y): - return 3*x+y - f = functools.lfu_cache(maxsize=20)(orig) - - domain = range(5) - for i in range(1000): - x, y = choice(domain), choice(domain) - actual = f(x, y) - expected = orig(x, y) - self.assertEquals(actual, expected) - self.assert_(f.hits > f.misses) - self.assertEquals(f.hits + f.misses, 1000) - - f.clear() # test clearing - self.assertEqual(f.hits, 0) - self.assertEqual(f.misses, 0) - f(x, y) - self.assertEqual(f.hits, 0) - self.assertEqual(f.misses, 1) - def test_main(verbose=None): test_classes = ( TestPartial, @@ -506,8 +461,7 @@ TestPythonPartial, TestUpdateWrapper, TestWraps, - TestReduce, - TestLRU, + TestReduce ) support.run_unittest(*test_classes) Modified: python/branches/py3k/Misc/NEWS ============================================================================== --- python/branches/py3k/Misc/NEWS (original) +++ python/branches/py3k/Misc/NEWS Sat Jul 31 12:16:21 2010 @@ -504,8 +504,6 @@ - Issue #4179: In pdb, allow "list ." as a command to return to the currently debugged line. -- Add lfu_cache() and lru_cache() decorators to the functools module. - - Issue #4108: In urllib.robotparser, if there are multiple 'User-agent: *' entries, consider the first one.