BUG: work around ndarray.round not preserving subclasses, GH #314

pandas/core/series.py

@@ -940,6 +940,17 @@ def _ndarray_statistic(self, funcname, dtype=None, skipna=True):
 
         return retVal
 
+    def round(self, decimals=0, out=None):
+        """
+
+        """
+        result = self.values.round(decimals, out=out)
+        if out is None:
+            result = Series(result, index=self.index, name=self.name)
+
+        return result
+    round.__doc__ = np.ndarray.round.__doc__
+
     def quantile(self, q=0.5):
         """
         Return value at the given quantile, a la scoreatpercentile in

pandas/tests/test_series.py

@@ -551,6 +551,14 @@ def _check_accum_op(self, name):
 
         self.assert_(np.array_equal(result, expected))
 
+    def test_round(self):
+        # numpy.round doesn't preserve metadata, probably a numpy bug,
+        # re: GH #314
+        result = np.round(self.ts, 2)
+        expected = Series(np.round(self.ts.values, 2), index=self.ts.index)
+        assert_series_equal(result, expected)
+        self.assertEqual(result.name, self.ts.name)
+
     def test_prod_numpy16_bug(self):
         s = Series([1., 1., 1.] , index=range(3))
         result = s.prod()