[Python-checkins] cpython: Unique sentinel value for cache.get()

[raymond.hettinger]

http://hg.python.org/cpython/rev/2d6eeb4ce0c8
changeset:   75758:2d6eeb4ce0c8
user:        Raymond Hettinger <python at rcn.com>
date:        Fri Mar 16 17:04:11 2012 -0700
summary:
  Unique sentinel value for cache.get()

files:
  Lib/functools.py |  4 ++--
  1 files changed, 2 insertions(+), 2 deletions(-)


diff --git a/Lib/functools.py b/Lib/functools.py
--- a/Lib/functools.py
+++ b/Lib/functools.py
@@ -175,8 +175,8 @@
                 # simple caching without ordering or size limit
                 nonlocal hits, misses
                 key = make_key(args, kwds, typed) if kwds or typed else args
-                result = cache_get(key)
-                if result is not None:
+                result = cache_get(key, root)   # root used here as a unique not-found sentinel        
+                if result is not root:
                     hits += 1
                     return result
                 result = user_function(*args, **kwds)

-- 
Repository URL: http://hg.python.org/cpython