Restore compatibility with python 2.6

63895ec09d5e28f4c3a308c737503c61e4e3bb43 accidentally broke python 2.6
compatibility due to usage of OrderedDict, which is not available
in the collections module in that version.

Possible fixes were:
1. Skip defining FrozenOrderedDict when running 2.6
2. Depend on ordereddict module when running 2.6 and import it when
needed
3. Copy OrderedDict recipe and use it when needed
4. Do not provide FrozenOrderedDict on 2.6

the last one was chosen due to maintainer preference to keep the code
base compact.

2 files changed, 13 insertions, 2 deletions

diff --git a/frozendict/__init__.py b/frozendict/__init__.py
index 9a63a65..2a6923a 100644
--- a/frozendict/__init__.py
+++ b/frozendict/__init__.py
@@ -1,6 +1,13 @@
 import collections
 import operator
 import functools
+import sys
+
+
+try:
+    from collections import OrderedDict
+except ImportError:  # python < 2.7
+    OrderedDict = NotImplemented
 
 
 class frozendict(collections.Mapping):
@@ -46,4 +53,8 @@ class FrozenOrderedDict(frozendict):
     A FrozenDict subclass that maintains key order
     """
 
-    dict_cls = collections.OrderedDict
+    dict_cls = OrderedDict
+
+
+if sys.version >= (2, 7):
+    del FrozenOrderedDict
diff --git a/setup.py b/setup.py
index 8258bf4..31efe0a 100644
--- a/setup.py
+++ b/setup.py
@@ -2,7 +2,7 @@ from setuptools import setup
 
 setup(
     name     = 'frozendict',
-    version  = '1.0',
+    version  = '1.1',
     url      = 'https://github.com/slezica/python-frozendict',
 
     author       = 'Santiago Lezica',