Attach establishment timestamps as command

apps/establishment/management/commands/attach_establishments_tz.py

@@ -0,0 +1,23 @@
+from django.core.management.base import BaseCommand
+from pytz import timezone as py_tz
+from timezonefinder import TimezoneFinder
+from establishment.models import Establishment
+
+
+class Command(BaseCommand):
+    help = 'Attach correct timestamps according to coordinates to existing establishments'
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.tf = TimezoneFinder(in_memory=True)
+
+    def handle(self, *args, **options):
+        for establishment in Establishment.objects.prefetch_related('address').all():
+            if establishment.address and establishment.address.latitude and establishment.address.longitude:
+                establishment.tz = py_tz(self.tf.certain_timezone_at(lng=establishment.address.longitude,
+                                                          lat=establishment.address.latitude))
+                establishment.save()
+                self.stdout.write(self.style.SUCCESS(f'Attached timezone {establishment.tz} to {establishment}'))
+            else:
+                self.stdout.write(self.style.WARNING(f'Establishment {establishment} has no coordinates'
+                                                     f'passing...'))

apps/establishment/migrations/0040_establishment_tz.py

@@ -3,17 +3,6 @@
 import timezone_field.fields
 from django.db import migrations
 from django.conf import settings
-from timezonefinder import TimezoneFinder
-from establishment.models import Establishment
-
-
-def fill_timezones(apps, schema_editor):
-    tf = TimezoneFinder(in_memory=True)
-    for establishment in Establishment.objects.prefetch_related('address').all():
-        if establishment.address and establishment.address.latitude and establishment.address.longitude:
-            establishment.tz = tf.certain_timezone_at(lng=establishment.address.longitude,
-                                                      lat=establishment.address.latitude)
-            establishment.save()
 
 
 class Migration(migrations.Migration):
@@ -29,5 +18,4 @@ class Migration(migrations.Migration):
             name='tz',
             field=timezone_field.fields.TimeZoneField(default=settings.TIME_ZONE),
         ),
-        migrations.RunPython(fill_timezones, migrations.RunPython.noop),
     ]