diff --git a/samples/client/petstore/python/README.md b/samples/client/petstore/python/README.md
index db827de9ceb2..3f9cea1e35aa 100644
--- a/samples/client/petstore/python/README.md
+++ b/samples/client/petstore/python/README.md
@@ -5,7 +5,7 @@ This Python package is automatically generated by the [Swagger Codegen](https://
 
 - API version: 1.0.0
 - Package version: 1.0.0
-- Build date: 2016-08-22T17:54:52.358+08:00
+- Build date: 2016-08-29T16:39:50.642+02:00
 - Build package: class io.swagger.codegen.languages.PythonClientCodegen
 
 ## Requirements.
diff --git a/samples/client/petstore/python/petstore_api/api_client.py b/samples/client/petstore/python/petstore_api/api_client.py
index ddfaf2ca7440..8fb86fc09644 100644
--- a/samples/client/petstore/python/petstore_api/api_client.py
+++ b/samples/client/petstore/python/petstore_api/api_client.py
@@ -581,6 +581,9 @@ class ApiClient(object):
         """
         instance = klass()
 
+        if not instance.swagger_types:
+            return data
+
         for attr, attr_type in iteritems(instance.swagger_types):
             if data is not None \
                and instance.attribute_map[attr] in data\