BUG: Float64Index with nans not comparing correctly

doc/source/release.rst

@@ -141,6 +141,7 @@ Bug Fixes
 - Bug in hdfstore queries of the form ``where=[('date', '>=', datetime(2013,1,1)), ('date', '<=', datetime(2014,1,1))]`` (:issue:`6313`)
 - Bug in DataFrame.dropna with duplicate indices (:issue:`6355`)
 - Regression in chained getitem indexing with embedded list-like from 0.12 (:issue:`6394`)
+- ``Float64Index`` with nans not comparing correctly
 
 pandas 0.13.1
 -------------

pandas/core/index.py

@@ -1950,8 +1950,14 @@ def equals(self, other):
         if self is other:
             return True
 
+        # need to compare nans locations and make sure that they are the same
+        # since nans don't compare equal this is a bit tricky
         try:
-            return np.array_equal(self, other)
+            if not isinstance(other, Float64Index):
+                other = self._constructor(other)
+            if self.dtype != other.dtype or self.shape != other.shape: return False
+            left, right = self.values, other.values
+            return ((left == right) | (isnull(left) & isnull(right))).all()
         except TypeError:
             # e.g. fails in numpy 1.6 with DatetimeIndex #1681
             return False

pandas/core/internals.py

@@ -1184,12 +1184,12 @@ class NumericBlock(Block):
 
 
 class FloatOrComplexBlock(NumericBlock):
+
     def equals(self, other):
         if self.dtype != other.dtype or self.shape != other.shape: return False
         left, right = self.values, other.values
         return ((left == right) | (np.isnan(left) & np.isnan(right))).all()
 
-
 class FloatBlock(FloatOrComplexBlock):
     is_float = True
     _downcast_dtype = 'int64'

pandas/tests/test_index.py

@@ -852,6 +852,21 @@ def test_astype(self):
         self.assert_(i.equals(result))
         self.check_is_index(result)
 
+    def test_equals(self):
+
+        i = Float64Index([1.0,2.0])
+        self.assertTrue(i.equals(i))
+        self.assertTrue(i.identical(i))
+
+        i2 = Float64Index([1.0,2.0])
+        self.assertTrue(i.equals(i2))
+
+        i = Float64Index([1.0,np.nan])
+        self.assertTrue(i.equals(i))
+        self.assertTrue(i.identical(i))
+
+        i2 = Float64Index([1.0,np.nan])
+        self.assertTrue(i.equals(i2))
 
 class TestInt64Index(tm.TestCase):
     _multiprocess_can_split_ = True