Move delete_file to signals.py

core/apps.py

@@ -4,3 +4,6 @@ from django.apps import AppConfig
 class CoreConfig(AppConfig):
     default_auto_field = "django.db.models.BigAutoField"
     name = "core"
+
+    def ready(self):
+        from . import signals

core/models/bid.py

@@ -1,7 +1,5 @@
-import os
 from django.core.exceptions import ValidationError
 from django.core.validators import RegexValidator
-from django.dispatch import receiver
 from django.db import models
 from django.forms.widgets import Select, CheckboxSelectMultiple
 from django.utils import timezone
@@ -274,15 +272,6 @@ class BaseBidDocument(BidRevChildMixin, Orderable, ClusterableModel):
         return b + r
 
 
-@receiver(models.signals.post_delete)
-def delete_file(sender, instance, **kwargs):
-    if isinstance(instance, BaseBidDocument):
-        if instance.file:
-            if os.path.isfile(instance.file.path):
-                if BaseBidDocument.count_file_uses(instance.file) == 0:
-                    os.remove(instance.file.path)
-
-
 class BidDocument(BaseBidDocument):
     bid = ParentalKey(Bid, on_delete=models.CASCADE, related_name='documents')
 

core/signals.py

@@ -0,0 +1,15 @@
+import os
+from django.db import models
+from django.dispatch import receiver
+from .models.bid import BaseBidDocument
+
+
+@receiver(models.signals.post_delete)
+def delete_file(sender, instance, **kwargs):
+    if isinstance(instance, BaseBidDocument) and \
+       instance.file and \
+       os.path.isfile(instance.file.path) and \
+       BaseBidDocument.count_file_uses(instance.file) == 0:
+        os.remove(instance.file.path)
+
+