remove backport of collections.OrderedDict for Py2.7 support

patsy/build.py

@@ -8,6 +8,7 @@
 __all__ = ["design_matrix_builders", "build_design_matrices"]
 
 import itertools
+from collections import OrderedDict
 
 import numpy as np
 from patsy import PatsyError
@@ -22,7 +23,6 @@
 from patsy.redundancy import pick_contrasts_for_term
 from patsy.eval import EvalEnvironment
 from patsy.contrasts import code_contrast_matrix, Treatment
-from patsy.compat import OrderedDict
 from patsy.missing import NAAction
 
 if have_pandas:

patsy/compat.py

@@ -21,14 +21,6 @@
 # add here explaining their provenance, any changes made, and what versions of
 # Python require them:
 
-# OrderedDict is only available in Python 2.7+. compat_ordereddict.py has
-# comments at the top.
-import collections
-
-if optional_dep_ok and hasattr(collections, "OrderedDict"):
-    from collections import OrderedDict
-else:
-    from patsy.compat_ordereddict import OrderedDict
 
 # 'raise from' available in Python 3+
 import sys

patsy/constraint.py

@@ -455,7 +455,7 @@ def _check_lincon(input, varnames, coefs, constants):
 
 def test_linear_constraint():
     import pytest
-    from patsy.compat import OrderedDict
+    from collections import OrderedDict
 
     t = _check_lincon
 

patsy/design_info.py

@@ -21,12 +21,12 @@
 __all__ = ["DesignInfo", "FactorInfo", "SubtermInfo", "DesignMatrix"]
 
 import warnings
+from collections import OrderedDict
 
 import numpy as np
 
 from patsy import PatsyError
 from patsy.util import atleast_2d_column_default
-from patsy.compat import OrderedDict
 from patsy.util import (
     repr_pretty_delegate,
     repr_pretty_impl,