BUG: incorrect conversion on isin algos with m8

Author: jreback

pandas/core/algorithms.py

@@ -174,7 +174,7 @@ def isin(comps, values):
                         " to isin(), you passed a "
                         "[{0}]".format(type(values).__name__))
 
-    from pandas import DatetimeIndex, PeriodIndex
+    from pandas import DatetimeIndex, TimedeltaIndex, PeriodIndex
 
     if not isinstance(values, (ABCIndex, ABCSeries, np.ndarray)):
         values = np.array(list(values), dtype='object')
@@ -183,6 +183,9 @@ def isin(comps, values):
         if is_period_dtype(values):
             comps = PeriodIndex(comps)
             values = PeriodIndex(values)
+        elif is_timedelta64_dtype(comps):
+            comps = TimedeltaIndex(comps)
+            values = TimedeltaIndex(values)
         else:
             comps = DatetimeIndex(comps)
             values = DatetimeIndex(values)

pandas/tests/test_algos.py

@@ -431,6 +431,8 @@ def test_basic(self):
         expected = np.array([False, False])
         tm.assert_numpy_array_equal(result, expected)
 
+    def test_i8(self):
+
         arr = pd.date_range('20130101', periods=3).values
         result = algos.isin(arr, [arr[0]])
         expected = np.array([True, False, False])