Preserve name for PeriodIndex field accessors

Author: jorisvandenbossche

pandas/tests/indexes/period/test_period.py

@@ -658,11 +658,11 @@ def test_negative_ordinals(self):
 
     def test_pindex_fieldaccessor_nat(self):
         idx = PeriodIndex(['2011-01', '2011-02', 'NaT',
-                           '2012-03', '2012-04'], freq='D')
+                           '2012-03', '2012-04'], freq='D', name='name')
 
-        exp = Index([2011, 2011, -1, 2012, 2012], dtype=np.int64)
+        exp = Index([2011, 2011, -1, 2012, 2012], dtype=np.int64, name='name')
         self.assert_index_equal(idx.year, exp)
-        exp = Index([1, 2, -1, 3, 4], dtype=np.int64)
+        exp = Index([1, 2, -1, 3, 4], dtype=np.int64, name='name')
         self.assert_index_equal(idx.month, exp)
 
     def test_pindex_qaccess(self):

pandas/tseries/period.py

@@ -53,7 +53,7 @@ def _field_accessor(name, alias, docstring=None):
     def f(self):
         base, mult = _gfc(self.freq)
         result = get_period_field_arr(alias, self._values, base)
-        return Index(result)
+        return Index(result, name=self.name)
     f.__name__ = name
     f.__doc__ = docstring
     return property(f)