Remove the lfu_cache. Add more tests.
diff --git a/Doc/whatsnew/3.2.rst b/Doc/whatsnew/3.2.rst
index bc31764..2c625a8 100644
--- a/Doc/whatsnew/3.2.rst
+++ b/Doc/whatsnew/3.2.rst
@@ -66,45 +66,32 @@
New, Improved, and Deprecated Modules
=====================================
-* The functools module now includes two new decorators for caching function
- calls, :func:`functools.lru_cache` and :func:`functools.lfu_cache`. These can
- save repeated queries to an external resource whenever the results are
- expected to be the same.
+* The functools module now includes a new decorator for caching function calls.
+ :func:`functools.lru_cache` can save repeated queries to an external resource
+ whenever the results are expected to be the same.
For example, adding a caching decorator to a database query function can save
database accesses for popular searches::
- @functools.lfu_cache(maxsize=50)
+ @functools.lru_cache(maxsize=300)
def get_phone_number(name):
c = conn.cursor()
c.execute('SELECT phonenumber FROM phonelist WHERE name=?', (name,))
return c.fetchone()[0]
- The caches support two strategies for limiting their size to *maxsize*. The
- LFU (least-frequently-used) cache works bests when popular queries remain the
- same over time. In contrast, the LRU (least-recently-used) cache works best
- query popularity changes over time (for example, the most popular news
- articles change each day as newer articles are added).
+ To help with choosing an effective cache size, the wrapped function is
+ instrumented with two attributes *hits* and *misses*::
- The two caching decorators can be composed (nested) to handle hybrid cases.
- For example, music searches can reflect both long-term patterns (popular
- classics) and short-term trends (new releases)::
-
- @functools.lfu_cache(maxsize=500)
- @functools.lru_cache(maxsize=100)
- def find_lyrics(song):
- query = 'http://www.example.com/songlist/%s' % urllib.quote(song)
- page = urllib.urlopen(query).read()
- return parse_lyrics(page)
-
- To help with choosing an effective cache size, the wrapped function
- is instrumented with two attributes *hits* and *misses*::
-
- >>> for song in user_requests:
- ... find_lyrics(song)
- >>> print(find_lyrics.hits, find_lyrics.misses)
+ >>> for name in user_requests:
+ ... get_phone_number(name)
+ >>> print(get_phone_number.hits, get_phone_number.misses)
4805 980
+ If the phonelist table gets updated, the outdated contents of the cache can be
+ cleared with::
+
+ >>> get_phone_number.clear()
+
(Contributed by Raymond Hettinger)
* The previously deprecated :func:`contextlib.nested` function has been