revert for period

Author: TomAugspurger

pandas/core/arrays/period.py

@@ -572,7 +572,7 @@ def asfreq(self, freq=None, how='E'):
     # ------------------------------------------------------------------
     # Rendering Methods
 
-    def _format_native_types(self, na_rep='NaT', date_format=None, **kwargs):
+    def _format_native_types(self, na_rep=u'NaT', date_format=None, **kwargs):
         """
         actually format my specific types
         """

pandas/core/indexes/period.py

@@ -395,7 +395,7 @@ def _maybe_convert_timedelta(self, other):
     # ------------------------------------------------------------------------
     # Rendering Methods
 
-    def _format_native_types(self, na_rep='NaT', quoting=None, **kwargs):
+    def _format_native_types(self, na_rep=u'NaT', quoting=None, **kwargs):
         # just dispatch, return ndarray
         return self._data._format_native_types(na_rep=na_rep,
                                                quoting=quoting,