BUG: work around matplotlib-related buglet, Index inserting newaxis issue

Author: wesm

pandas/core/index.py

@@ -59,6 +59,7 @@ def __new__(cls, data, dtype=None, copy=False, name=None):
         if isinstance(data, np.ndarray):
             if dtype is None and issubclass(data.dtype.type, np.integer):
                 return Int64Index(data, copy=copy, name=name)
+
             subarr = np.array(data, dtype=object, copy=copy)
         elif np.isscalar(data):
             raise ValueError('Index(...) must be called with a collection '
@@ -209,7 +210,11 @@ def __getitem__(self, key):
             if _is_bool_indexer(key):
                 key = np.asarray(key)
 
-            return Index(arr_idx[key], name=self.name)
+            result = arr_idx[key]
+            if result.ndim > 1:
+                return result
+
+            return Index(result, name=self.name)
 
     def append(self, other):
         """

pandas/tests/test_index.py

@@ -24,6 +24,11 @@ def setUp(self):
     def test_hash_error(self):
         self.assertRaises(TypeError, hash, self.strIndex)
 
+    def test_new_axis(self):
+        new_index = self.dateIndex[None, :]
+        self.assert_(new_index.ndim == 2)
+        self.assert_(type(new_index) == np.ndarray)
+
     def test_deepcopy(self):
         from copy import deepcopy