From 93972dc1fb28ddcebb9c86a7b8ce6cd9a39f60ff Mon Sep 17 00:00:00 2001
From: pilkibun <pilkibun@users.noreply.github.com>
Date: Sat, 15 Jun 2019 07:35:36 +0300
Subject: [PATCH 1/2] CLN: In DecimalArray implement aliases as properties

Much safer, since _data may be assigned to
---
 pandas/tests/extension/decimal/array.py | 26 +++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/pandas/tests/extension/decimal/array.py b/pandas/tests/extension/decimal/array.py
index 3b95c8d919eb1..e64ccce52c2c9 100644
--- a/pandas/tests/extension/decimal/array.py
+++ b/pandas/tests/extension/decimal/array.py
@@ -59,14 +59,28 @@ def __init__(self, values, dtype=None, copy=False, context=None):
         values = np.asarray(values, dtype=object)
 
         self._data = values
-        # Some aliases for common attribute names to ensure pandas supports
-        # these
-        self._items = self.data = self._data
-        # those aliases are currently not working due to assumptions
-        # in internal code (GH-20735)
-        # self._values = self.values = self.data
         self._dtype = DecimalDtype(context)
 
+    # aliases for common attribute names, to ensure pandas supports these
+    @property
+    def _items(self):
+        return self._data
+
+    @property
+    def data(self):
+        return self._data
+
+    # those aliases are currently not working due to assumptions
+    # in internal code (GH-20735)
+    # @property
+    # def _values(self):
+    #     return self._data
+
+    # @property
+    # def values(self):
+    #     return self._data
+    # end aliases
+
     @property
     def dtype(self):
         return self._dtype

From 914840abc8e8e2c08d20dd27856928bc49d9080f Mon Sep 17 00:00:00 2001
From: pilkibun <pilkibun@users.noreply.github.com>
Date: Wed, 19 Jun 2019 10:08:29 +0300
Subject: [PATCH 2/2] Improve comment

---
 pandas/tests/extension/decimal/array.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/pandas/tests/extension/decimal/array.py b/pandas/tests/extension/decimal/array.py
index e64ccce52c2c9..aa53489ab7d4d 100644
--- a/pandas/tests/extension/decimal/array.py
+++ b/pandas/tests/extension/decimal/array.py
@@ -61,7 +61,9 @@ def __init__(self, values, dtype=None, copy=False, context=None):
         self._data = values
         self._dtype = DecimalDtype(context)
 
-    # aliases for common attribute names, to ensure pandas supports these
+    # Certain pandas function currently refer to these attributes
+    # expecting them to return a numpy array of values. here we
+    # just treat them as synonyms for `self._data`.
     @property
     def _items(self):
         return self._data