Mykola

NOT NULL constraint failed: news_articles.author_id

class MasterChoiceField(forms.ModelChoiceField):
     def label_from_instance(self, obj):
         return obj.get_full_name()


class MasterAdmin(admin.ModelAdmin):
    ...

    def formfield_for_foreignkey(self, db_field, request, **kwargs):
        if db_field.name == 'master':
            return MasterChoiceField(queryset=User.objects.all())
        return super().formfield_for_foreignkey(db_field, request, **kwargs)

from os.path import splitext
from uuid import uuid4
from django.core.files.storage import FileSystemStorage

class UUIDFileStorage(FileSystemStorage):
    def get_available_name(self, name, max_length=None):
        _, ext = path.splitext(name)
        return uuid4().hex + ext

class SomeModel(models.Model):
    some_filed = models.ImageField('Какое-то изображение', upload_to='someimages', storage=UUIDFileStorage())

from rest_framework.response import Response


class TrainingDetailAPIView(RetrieveAPIView):
    queryset = Training.objects.all()
    serializer_class = TrainingSerializer
    lookup_field = 'slug'
    
    def retrieve(self, request, *args, **kwargs):
        instance = self.get_object()
        serializer = self.get_serializer(instance, fields=('title', 'description'))
        return Response(serializer.data)

class TrainingDetailAPIView(RetrieveAPIView):
    queryset = Training.objects.all()
    serializer_class = TrainingSerializer
    lookup_field = 'slug'
    
    def get_serializer(self, *args, **kwargs):
        kwargs['fields'] = ('title', 'description')
        return super().get_serializer(*args, **kwargs)

class ShowFieldsMixin:

    def get_serializer(self, *args, **kwargs):
        if getattr(self, 'fields_to_show', None) is not None:
            kwargs['fields'] = self.fields_to_show
        return super().get_serializer(*args, **kwargs)


class TrainingDetailAPIView(ShowFieldsMixin, RetrieveAPIView):
    queryset = Training.objects.all()
    serializer_class = TrainingSerializer
    lookup_field = 'slug'
    fields_to_show = ('title', 'description')

class TrainingListAPIView(ShowFieldsMixin, ListAPIView):
    # bla-bla-bla
    serializer_class = TrainingSerializer
    fields_to_show = ('name', 'description', 'url', 'slug')

..
celery==X.Y.Z 
..

return render(request, 'template.html', {'user': user, 'user_info': user_info})