Ignore None when passed in as response override

Closes #148

src/drf_yasg/inspectors/view.py

@@ -230,6 +230,8 @@ class SwaggerAutoSchema(ViewInspector):
                 response = openapi.Response(
                     description=serializer
                 )
+            elif not serializer:
+                continue
             elif isinstance(serializer, openapi.Response):
                 response = serializer
                 if hasattr(response, 'schema') and not isinstance(response.schema, openapi.Schema.OR_REF):

src/drf_yasg/utils.py

@@ -76,6 +76,8 @@ def swagger_auto_schema(method=None, methods=None, auto_schema=unset, request_bo
 
         * if a plain string is given as value, a :class:`.Response` with no body and that string as its description
           will be generated
+        * if ``None`` is given as a value, the response is ignored; this is mainly useful for disabling default
+          2xx responses, i.e. ``responses={200: None, 302: 'something'}``
         * if a :class:`.Schema`, :class:`.SchemaRef` is given, a :class:`.Response` with the schema as its body and
           an empty description will be generated
         * a ``Serializer`` class or instance will be converted into a :class:`.Schema` and treated as above

testproj/todo/views.py

@@ -57,7 +57,7 @@ class TodoRecursiveView(viewsets.ModelViewSet):
     def create(self, request, *args, **kwargs):
         return super(TodoRecursiveView, self).create(request, *args, **kwargs)
 
-    @swagger_auto_schema(responses={200: TodoRecursiveSerializer})
+    @swagger_auto_schema(responses={200: None, 302: 'Redirect somewhere'})
     def retrieve(self, request, *args, **kwargs):
         return super(TodoRecursiveView, self).retrieve(request, *args, **kwargs)
 

tests/reference.yaml

@@ -560,10 +560,8 @@ paths:
       description: ''
       parameters: []
       responses:
-        '200':
-          description: ''
-          schema:
-            $ref: '#/definitions/TodoRecursive'
+        '302':
+          description: Redirect somewhere
       tags:
         - todo
     put: