Improve code readability in moderation models using walrus operator

moderation/models.py

@@ -79,26 +79,23 @@ class EditSubmission(models.Model):
 
     def __str__(self) -> str:
         action = "creation" if self.submission_type == "CREATE" else "edit"
-        model_class = self.content_type.model_class()
-        target = self.content_object or (
-            model_class.__name__ if model_class else "Unknown"
-        )
+        if model_class := self.content_type.model_class():
+            target = self.content_object or model_class.__name__
+        else:
+            target = "Unknown"
         return f"{action} by {self.user.username} on {target}"
 
     def _resolve_foreign_keys(self, data: Dict[str, Any]) -> Dict[str, Any]:
         """Convert foreign key IDs to model instances"""
-        model_class = self.content_type.model_class()
-        if not model_class:
+        if not (model_class := self.content_type.model_class()):
             raise ValueError("Could not resolve model class")
 
         resolved_data = data.copy()
 
         for field_name, value in data.items():
             try:
-                field = model_class._meta.get_field(field_name)
-                if isinstance(field, models.ForeignKey) and value is not None:
-                    related_model = field.related_model
-                    if related_model:
+                if (field := model_class._meta.get_field(field_name)) and isinstance(field, models.ForeignKey) and value is not None:
+                    if related_model := field.related_model:
                         resolved_data[field_name] = related_model.objects.get(id=value)
             except (FieldDoesNotExist, ObjectDoesNotExist):
                 continue
@@ -111,8 +108,7 @@ class EditSubmission(models.Model):
         self.handled_by = user  # type: ignore
         self.handled_at = timezone.now()
 
-        model_class = self.content_type.model_class()
-        if not model_class:
+        if not (model_class := self.content_type.model_class()):
             raise ValueError("Could not resolve model class")
 
         try:
@@ -126,8 +122,7 @@ class EditSubmission(models.Model):
                 self.object_id = getattr(obj, "id", None)
             else:
                 # Apply changes to existing object
-                obj = self.content_object
-                if not obj:
+                if not (obj := self.content_object):
                     raise ValueError("Content object not found")
                 for field, value in resolved_data.items():
                     setattr(obj, field, value)