Upload multiple images to a model in Django

하나의 모델에 여러 장의 이미지를 포함시키고 싶은 경우

# models.py

class Post(models.Model):
    user = models.ForeignKey(User)
    title = models.CharField(max_length=128)
    body = models.CharField(max_length=400)

    
def get_image_filename(instance, filename):
    id = instance.post.id
    return "post_images/%s" % (id)  

  
class Images(models.Model):
    post = models.ForeignKey(Post, default=None)
    image = models.ImageField(upload_to=get_image_filename,
                              verbose_name='Image')

# forms.py

class PostForm(forms.ModelForm):
    title = forms.CharField(max_length=128)
    body = forms.CharField(max_length=245, label="Item Description.")

    class Meta:
        model = Post
        fields = ('title', 'body', )

        
class ImageForm(forms.ModelForm):
    image = forms.ImageField(label='Image')    
    class Meta:
        model = Images
        fields = ('image', )

# views.py

@login_required
def post(request):
    ImageFormSet = modelformset_factory(Images,
                                        form=ImageForm, extra=3)
    if request.method == 'POST':
        form = PostForm(request.POST)
        formset = ImageFormSet(request.POST, request.FILES,
                               queryset=Images.objects.none())
        if form.is_valid() and formset.is_valid():
            post = form.save(commit=False)
            post.user = request.user
            post.save()
            for form in formset.cleaned_data:
                image = form['image']
                photo = Images(post=post, image=image)
                photo.save()
            messages.success(request,
                             "Posted!")
            return HttpResponseRedirect("/")
        else:
            print form.errors, formset.errors
    else:
        form = PostForm()
        formset = ImageFormSet(queryset=Images.objects.none())
    return render(request, 'index.html',
                  {'postForm': form, 'formset': formset},
                  context_instance=RequestContext(request))

# index.html
<form id="post_form" method="post" action="" enctype="multipart/form-data">
    {% csrf_token %}
    {% for hidden in postForm.hidden_fields %}
        {{ hidden }}
    {% endfor %}

    {% for field in postForm %}
        {{ field }} <br />
    {% endfor %}

    {{ formset.management_form }}
    {% for form in formset %}
        {{ form }}
    {% endfor %}

    <input type="submit" name="submit" value="Submit" />
</form>

참고
(https://medium.com/@qasimalbaqali/upload-multiple-images-to-a-post-in-django-ff10f66e8f7a)