Adicionar em massa com unique_together

models.py

from django.db import models
from django.urls import reverse


class Question(models.Model):
    LEVEL_CHOICES = (
        ('0', 'Dependencia'),
        ('1', 'Confianca'),
        ('2', 'Comprometimento'),
        ('3', 'Preditiva'),
    )
    question = models.CharField('Pergunta', max_length=200)
    level = models.CharField('Nível', max_length=15,
                             choices=LEVEL_CHOICES, default='0')

    class Meta:
        verbose_name = 'Questão'
        verbose_name_plural = 'Questões'
        ordering = ('-level',)

    def __str__(self):
        return self.question


class Search(models.Model):
    search_key = models.CharField(
        'Período', max_length=200, db_index=False)
    person = models.ForeignKey(
        'core.client', related_name='Cliente', on_delete=models.CASCADE)
    researched = models.CharField('Entrevistado', max_length=200)
    participation_on = models.DateField(
        'Período da pesquisa',
        auto_now_add=True,
        auto_now=False
    )
    created_on = models.DateTimeField(
        'Solicitado em',
        auto_now_add=True,
        auto_now=False
    )

    class Meta:
        verbose_name = 'Pesquisa'
        verbose_name_plural = 'Pesquisas'
        unique_together = (('search_key', 'person'),)
        ordering = ('-participation_on',)

    def get_absolute_url(self):
        return reverse('person_client_detail', args=[str(self.pk)])

    def __str__(self):
        return self.search_key


def post_save_search(sender, instance, created,  **kwargs):
    if created:
        questions = Question.objects.all()
        search = Search.objects.filter(pk=instance.pk)

        print(search)

        lista = []

        for question in questions:
            try:
                SearchItem.objects.get(
                    search_id=instance.pk,
                    question_id=question.pk,
                    response=False,
                )
            except SearchItem.DoesNotExist:
                SearchItem.objects.get_or_create(
                    search_id=instance.pk,
                    question_id=question.pk,
                    response=False,
                )


models.signals.post_save.connect(
    post_save_search, sender=Search, dispatch_uid='post_save_search'
)


class SearchItem(models.Model):
    RESPONSE_CHOICES = (
        ('V', 'Verdadeiro'),
        ('F', 'Falso'),
        ('I', 'Indefinido'),
    )

    search = models.ForeignKey(
        'core.search', related_name='Periodo', on_delete=models.CASCADE, verbose_name="Período da Pesquisa")
    question = models.ForeignKey(
        'core.question', related_name='Pergunta', on_delete=models.CASCADE, verbose_name="Pergunta")
    response = models.BooleanField('Resposta')

    class Meta:
        verbose_name = 'Pesquisa Detalhe'
        verbose_name_plural = 'Pesquisas Detalhe'
        unique_together = (('search', 'question', 'response'),)
        ordering = ('-question',)

    def __str__(self):
        return self.question.question

try:
    # Bloco antigo sem alterar nada
except SearchItem.DoesNotExist:
    continue # ou pass
    # Ignora o erro e pula para a próxima iteração do for