      mode = models.CharField(max_length=2, choices=MODE_CHOICES, default=default_mode)
      category = models.IntegerField(choices=CATEGORY_CHOICES, default=default_category)
  
  
  class Author(models.Model):
      publication = models.OneToOneField(Publication, models.SET_NULL, null=True, blank=True)
      full_name = models.CharField(max_length=255)
 
</s> remove                 fields = '__all__'
 </s> add                 fields = ('title', 'date_published', 'mode', 'category') </s> remove         form = DerivedBookForm({'title': 'Other', 'author': self.writer.pk, 'isbn': isbn})
 </s> add         form = DerivedBookForm({
            'title': 'Other', 'author': self.writer.pk, 'isbn': isbn,
            'suffix1': '1', 'suffix2': '2',
        })
    active = models.BooleanField(default=True)
      mode = models.CharField(max_length=2, choices=MODE_CHOICES, default=default_mode)
      category = models.IntegerField(choices=CATEGORY_CHOICES, default=default_category)
    active = models.BooleanField(default=True)
  
  
  class Author(models.Model):
      publication = models.OneToOneField(Publication, models.SET_NULL, null=True, blank=True)
      full_name = models.CharField(max_length=255)
keep add keep keep keep keep keep
 Fixed #27039 -- Fixed empty data fallback to model field default in model forms. 
tests/model_forms/models.py