From 5cd038c8918e12d2bb752f8cebb150cb0b2ad1a0 Mon Sep 17 00:00:00 2001
From: Jeff Pinner <jpinner@lyft.com>
Date: Tue, 17 Oct 2017 15:07:14 -0700
Subject: [PATCH] 1.5.4 -- patch release to prepare for pull request #158 in
 1.6.0

---
 pynamodb/__init__.py              |  2 +-
 pynamodb/attributes.py            | 18 ++++++++++++++++++
 pynamodb/tests/test_attributes.py | 17 +++++++++++++++--
 3 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/pynamodb/__init__.py b/pynamodb/__init__.py
index 17b87a403..d3db1f949 100644
--- a/pynamodb/__init__.py
+++ b/pynamodb/__init__.py
@@ -7,4 +7,4 @@
 """
 __author__ = 'Jharrod LaFon'
 __license__ = 'MIT'
-__version__ = '1.5.3'
+__version__ = '1.5.4'
diff --git a/pynamodb/attributes.py b/pynamodb/attributes.py
index d5d44c033..3f6e2c717 100644
--- a/pynamodb/attributes.py
+++ b/pynamodb/attributes.py
@@ -140,6 +140,24 @@ class UnicodeSetAttribute(SetMixin, Attribute):
     attr_type = STRING_SET
     null = True
 
+    def element_deserialize(self, value):
+        """
+        This prepares for a future serialization change in v1.6.0 which will stop
+        serializing json encoded strings. This method attempts to deserialize a json
+        encoded value and falls back to returning the raw value if json decoding fails.
+        """
+        result = value
+        try:
+            result = json.loads(value)
+        except ValueError:
+            # it's serialized in the new way so pass
+            pass
+        return result
+
+    def deserialize(self, value):
+        if value and len(value):
+            return set([self.element_deserialize(val) for val in value])
+
 
 class UnicodeAttribute(Attribute):
     """
diff --git a/pynamodb/tests/test_attributes.py b/pynamodb/tests/test_attributes.py
index 8e334815f..bbf405135 100644
--- a/pynamodb/tests/test_attributes.py
+++ b/pynamodb/tests/test_attributes.py
@@ -353,9 +353,22 @@ def test_unicode_set_deserialize(self):
         UnicodeSetAttribute.deserialize
         """
         attr = UnicodeSetAttribute()
+        value = set([six.u('foo'), six.u('bar')])
         self.assertEqual(
-            attr.deserialize([json.dumps(val) for val in sorted(set([six.u('foo'), six.u('bar')]))]),
-            set([six.u('foo'), six.u('bar')])
+            attr.deserialize(value),
+            value
+        )
+
+    def test_unicode_set_deserialize_json(self):
+        """
+        UnicodeSetAttribute.deserialize old way
+        """
+        attr = UnicodeSetAttribute()
+        value = set([six.u('foo'), six.u('bar')])
+        old_value = set([json.dumps(val) for val in value])
+        self.assertEqual(
+            attr.deserialize(old_value),
+            value
         )
 
     def test_unicode_set_attribute(self):