Update openapi.py

Author: lovelydinosaur

rest_framework/schemas/openapi.py

@@ -393,7 +393,7 @@ def _map_serializer(self, serializer):
                 schema['writeOnly'] = True
             if field.allow_null:
                 schema['nullable'] = True
-            if field.default and field.default != empty and not callable(field.default):  # why don't they use None?!
+            if field.default and field.default != empty and not callable(field.default):
                 schema['default'] = field.default
             if field.help_text:
                 schema['description'] = str(field.help_text)