allow unstructured map attributes (#186)

Author: jmphilli

pynamodb/models.py

@@ -1203,7 +1203,7 @@ def _serialize(self, attr_map=False, null_check=True):
                     continue
                 elif null_check:
                     raise ValueError("Attribute '{0}' cannot be None".format(attr.attr_name))
-            if isinstance(attr, MapAttribute):
+            if isinstance(value, MapAttribute):
                 if not value.validate():
                     raise ValueError("Attribute '{0}' is not correctly typed".format(attr.attr_name))
                 value = value.get_values()

pynamodb/tests/test_model.py

@@ -396,6 +396,13 @@ class Meta:
     right = TreeLeaf()
 
 
+class ExplicitRawMapModel(Model):
+    class Meta:
+        table_name = 'ExplicitRawMapModel'
+
+    map_attr = MapAttribute()
+
+
 class OverriddenSession(requests.Session):
     """
     A overridden session for test
@@ -2996,3 +3003,51 @@ def test_result_set_iter(self):
         rs = ResultSet(results=results, operation=operations, arguments=arguments)
         for k in rs:
             self.assertTrue(k in results)
+
+    def test_explicit_raw_map_serialize_pass(self):
+        map_native = {'foo': 'bar'}
+        map_serialized = {'M': {'foo': {'S': 'bar'}}}
+        instance = ExplicitRawMapModel(map_attr=map_native)
+        serialized = instance._serialize()
+        self.assertEqual(serialized['attributes']['map_attr'], map_serialized)
+
+    def test_raw_map_serialize_fun_one(self):
+        map_native = {
+            'foo': 'bar', 'num': 1, 'bool_type': True,
+            'other_b_type': False, 'floaty': 1.2, 'listy': [1,2,3],
+            'mapy': {'baz': 'bongo'}
+        }
+        expected = {'M': {'foo': {'S': u'bar'},
+               'listy': {'L': [{'N': '1'}, {'N': '2'}, {'N': '3'}]},
+               'num': {'N': '1'}, 'other_b_type': {'BOOL': False},
+               'floaty': {'N': '1.2'}, 'mapy': {'M': {'baz': {'S': u'bongo'}}},
+               'bool_type': {'BOOL': True}}}
+
+        instance = ExplicitRawMapModel(map_attr=map_native)
+        serialized = instance._serialize()
+        actual = serialized['attributes']['map_attr']
+        self.assertEqual(expected, actual)
+
+    def test_raw_map_deserializes(self):
+        map_native = {
+            'foo': 'bar', 'num': 1, 'bool_type': True,
+            'other_b_type': False, 'floaty': 1.2, 'listy': [1, 2, 3],
+            'mapy': {'baz': 'bongo'}
+        }
+        map_serialized = {
+            'M': {
+                'foo': {'S': 'bar'},
+                'num': {'N': 1},
+                'bool_type': {'BOOL': True},
+                'other_b_type': {'BOOL': False},
+                'floaty': {'N': 1.2},
+                'listy': {'L': [{'N': 1}, {'N': 2}, {'N': 3}]},
+                'mapy': {'M': {'baz': {'S': 'bongo'}}}
+            }
+        }
+        instance = ExplicitRawMapModel(map_attr=map_native)
+        instance._deserialize(map_serialized)
+        actual = instance.map_attr
+        for k,v in six.iteritems(map_native):
+            self.assertEqual(v, actual[k])
+