From 89194ff2807e040804c2fa8a92a1da04844471a2 Mon Sep 17 00:00:00 2001
From: Raymond Hettinger <python@rcn.com>
Date: Tue, 3 Mar 2009 22:42:48 +0000
Subject: [PATCH] Now that __keys are fully hidden, switch the underlying
 structure to deque() which futher reduces the temptation to index or resort.
 Also, it is a bit faster for some cases.

---
 Lib/collections.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Lib/collections.py b/Lib/collections.py
index a1e8ed975bf..2b0de187684 100644
--- a/Lib/collections.py
+++ b/Lib/collections.py
@@ -27,11 +27,11 @@ class OrderedDict(dict, MutableMapping):
         except AttributeError:
             # Note the underlying data structure for this class is likely to
             # change in the future.  Do not rely on it or access it directly.
-            self.__keys = []
+            self.__keys = deque()
         self.update(*args, **kwds)
 
     def clear(self):
-        del self.__keys[:]
+        self.__keys.clear()
         dict.clear(self)
 
     def __setitem__(self, key, value):