diff --git a/rest_framework/serializers.py b/rest_framework/serializers.py
index fd226f277..3efb71e06 100644
--- a/rest_framework/serializers.py
+++ b/rest_framework/serializers.py
@@ -1111,19 +1111,19 @@ class ModelSerializer(Serializer):
 
             # Create the serializer field.
             fields[field_name] = field_class(**field_kwargs)
-        property_fields = getattr(self.Meta, 'property_fields',None)
+        property_fields = getattr(self.Meta, 'property_fields', None)
         if property_fields:
             if property_fields == '__all__':
                 for attr_name in dir(model):
-                    attr = getattr(model,attr_name)
-                    if isinstance(attr,property):
+                    attr = getattr(model, attr_name)
+                    if isinstance(attr, property):
                         fields[attr_name] = ReadOnlyField()
-            elif isinstance(property_fields,list) or isinstance(property_fields,tuple):
+            elif isinstance(property_fields, list) or isinstance(property_fields, tuple):
                 for attr_name in property_fields:
-                    attr = getattr(model,attr_name,None)
+                    attr = getattr(model, attr_name, None)
                     if not attr:
                         raise ValueError(f"{attr_name}  this field doesn't exist in {model} model property")
-                    if isinstance(attr,property):
+                    if isinstance(attr, property):
                         fields[attr_name] = ReadOnlyField()
             else:
                 raise ValueError("Please select the appropriate value for property_fields in the serializer. Use __all__ to include all property fields, or provide a tuple or list to manually specify the property fields you want to include.")