gistfile1.py

class Model1(models.Model):
  pass

class Model2(models.Model):
  model1 = OneToOneField('Model1')
  
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class myView(UpdateView):
  ...
  def get_context_data(self, **kwargs):
    model1 = Model1.objects.get(pk=self.pk_url_kwargs)
    model2, created = Model2.objects.get_or_create(model1=model1)
    return model2