Fix Timestamp __ne__ comparison issue

Author: cpcloud

doc/source/whatsnew/v0.17.0.txt

@@ -227,7 +227,7 @@ See the :ref:`documentation <io.excel>` for more details.
 
    df = pd.read_excel('test.xlsx', header=[0,1], index_col=[0,1])
    df
-    
+
 .. ipython:: python
    :suppress:
 
@@ -494,7 +494,7 @@ Datetime with TZ
 
 We are adding an implementation that natively supports datetime with timezones. A ``Series`` or a ``DataFrame`` column previously
 *could* be assigned a datetime with timezones, and would work as an ``object`` dtype. This had performance issues with a large
-number rows. See the :ref:`docs <timeseries.timezone_series>` for more details. (:issue:`8260`, :issue:`10763`).
+number rows. See the :ref:`docs <timeseries.timezone_series>` for more details. (:issue:`8260`, :issue:`10763`, :issue:`11034`).
 
 The new implementation allows for having a single-timezone across all rows, with operations in a performant manner.
 
@@ -966,7 +966,6 @@ Bug Fixes
 - Bug in ``Series.count`` when index has nulls (:issue:`10946`)
 - Bug in pickling of a non-regular freq ``DatetimeIndex`` (:issue:`11002`)
 - Bug causing ``DataFrame.where`` to not respect the ``axis`` parameter when the frame has a symmetric shape. (:issue:`9736`)
-
 - Bug in ``Table.select_column`` where name is not preserved (:issue:`10392`)
 - Bug in ``offsets.generate_range`` where ``start`` and ``end`` have finer precision than ``offset`` (:issue:`9907`)
 - Bug in ``pd.rolling_*`` where ``Series.name`` would be lost in the output (:issue:`10565`)

pandas/core/ops.py

@@ -672,10 +672,7 @@ def na_op(x, y):
                 else:
                     y = y.view('i8')
 
-                if name == '__ne__':
-                    mask = notnull(x)
-                else:
-                    mask = isnull(x)
+                mask = isnull(x)
 
                 x = x.view('i8')
 

pandas/tseries/tests/test_timeseries.py

@@ -2152,7 +2152,6 @@ def test_period_resample_with_local_timezone_dateutil(self):
         expected = pd.Series(1, index=expected_index)
         assert_series_equal(result, expected)
 
-
     def test_pickle(self):
 
         # GH4606
@@ -2171,6 +2170,26 @@ def test_pickle(self):
         idx_p = self.round_trip_pickle(idx)
         tm.assert_index_equal(idx, idx_p)
 
+    def test_timestamp_equality(self):
+
+        # GH 11034
+        s = Series([Timestamp('2000-01-29 01:59:00'),'NaT'])
+        result = s != s
+        assert_series_equal(result, Series([False,True]))
+        result = s != s[0]
+        assert_series_equal(result, Series([False,True]))
+        result = s != s[1]
+        assert_series_equal(result, Series([True,True]))
+
+        result = s == s
+        assert_series_equal(result, Series([True,False]))
+        result = s == s[0]
+        assert_series_equal(result, Series([True,False]))
+        result = s == s[1]
+        assert_series_equal(result, Series([False,False]))
+
+
+
 def _simple_ts(start, end, freq='D'):
     rng = date_range(start, end, freq=freq)
     return Series(np.random.randn(len(rng)), index=rng)