Django transaction.atomic()不工作

我对这个代码有问题:

PhoneNumberFormSet = inlineformset_factory(Person, PhoneNumber, fields=('phone_number',), 
can_delete=False, extra=1)

EmailAddressFormSet = inlineformset_factory(Person, EmailAddress, fields=('email_address',), 
can_delete=False, extra=1)

class PersonCreateView(CreateView):

    form_class = PersonForm
    success_url = reverse_lazy('person-list')
    template_name = 'contacts/person_create.html'

    def get_context_data(self, **kwargs):
        data = super(PersonCreateView, self).get_context_data(**kwargs)
        data['phone_formset'] = PhoneNumberFormSet(self.request.POST or None)
        data['email_formset'] = EmailAddressFormSet(self.request.POST or None)
        return data

    def form_valid(self, form):
        context = self.get_context_data()
        phone_formset = context['phone_formset']
        email_formset = context['email_formset']
        with transaction.atomic():
            o = form.save() # <--- this object is saved even when formsets below are not valid
            condition = phone_formset.is_valid() and email_formset.is_valid()
            if not condition:
                return render(self.request, self.template_name, self.get_context_data())
            phone_formset.instance = o
            phone_formset.save()
            email_formset.instance = o
            email_formset.save()
        return super(PersonCreateView, self).form_valid(form)

transaction.atomic()正在保存对象“o”,即使phone\u formset或email\u formset无效并且view呈现有错误的表单(不应保存对象)