BIG UPD: migrate to python 3.10 and django 3.2

dav_registration/models.py

@@ -6,7 +6,6 @@ from django.core.exceptions import ValidationError
 from django.db import models
 from django.urls import reverse
 from django.utils import timezone
-from django.utils.encoding import python_2_unicode_compatible
 from django.utils.translation import ugettext_lazy as _
 
 from dav_base.validators import DAVNumberValidator
@@ -19,9 +18,8 @@ logger = logging.getLogger(__name__)
 midnight = datetime.time(00, 00, 00)
 
 
-@python_2_unicode_compatible
 class Registration(models.Model):
-    event = models.ForeignKey(Event, related_name='registrations')
+    event = models.ForeignKey(Event, related_name='registrations', on_delete=models.PROTECT)
     created_at = models.DateTimeField(auto_now_add=True)
 
     personal_names = models.CharField(max_length=1024,
@@ -219,11 +217,11 @@ Anmerkung:
         return timezone.make_aware(datetime.datetime.combine(purge_date, midnight))
 
 
-@python_2_unicode_compatible
 class RegistrationStatus(models.Model):
     registration = models.OneToOneField(Registration, on_delete=models.CASCADE, related_name='status')
     updated_at = models.DateTimeField(auto_now=True)
     answered = models.BooleanField(_('Durch Tourleitung beantwortet'), default=False)
+    # TODO: NullBooleanField is marked deprecated
     accepted = models.NullBooleanField(_('Zusage erteilt'))
 
     class Meta: