Merge pull request #3591 from jreback/groupby_period_index

BUG: fix take platorm issue with PeriodIndex (GH3579)

Author: jreback

RELEASE.rst

@@ -103,6 +103,7 @@ pandas 0.11.1
   - Fix ``.diff`` on datelike and timedelta operations (GH3100_)
   - ``combine_first`` not returning the same dtype in cases where it can (GH3552_)
   - Fixed bug with ``Panel.transpose`` argument aliases (GH3556_)
+  - Fixed platform bug in ``PeriodIndex.take`` (GH3579_)
   - Fixed bug in reset_index with ``NaN`` in a multi-index (GH3586_)
 
 .. _GH3164: https://github.com/pydata/pandas/issues/3164
@@ -143,6 +144,7 @@ pandas 0.11.1
 .. _GH3562: https://github.com/pydata/pandas/issues/3562
 .. _GH3586: https://github.com/pydata/pandas/issues/3586
 .. _GH3493: https://github.com/pydata/pandas/issues/3493
+.. _GH3579: https://github.com/pydata/pandas/issues/3579
 .. _GH3556: https://github.com/pydata/pandas/issues/3556
 
 

pandas/tests/test_groupby.py

@@ -318,6 +318,15 @@ def test_agg_period_index(self):
         rs = df.groupby(level=0).sum()
         self.assert_(isinstance(rs.index, PeriodIndex))
 
+        # GH 3579
+        index = period_range(start='1999-01', periods=5, freq='M')
+        s1 = Series(np.random.rand(len(index)), index=index)
+        s2 = Series(np.random.rand(len(index)), index=index)
+        series = [('s1', s1), ('s2',s2)]
+        df = DataFrame.from_items(series)
+        grouped = df.groupby(df.index.month)
+        list(grouped)
+
     def test_agg_must_agg(self):
         grouped = self.df.groupby('A')['C']
         self.assertRaises(Exception, grouped.agg, lambda x: x.describe())

pandas/tseries/period.py

@@ -1125,6 +1125,7 @@ def take(self, indices, axis=None):
         """
         Analogous to ndarray.take
         """
+        indices = com._ensure_platform_int(indices)
         taken = self.values.take(indices, axis=axis)
         taken = taken.view(PeriodIndex)
         taken.freq = self.freq