Type object 'Post' has no attribute 'published' Django

Question

I am working on an application and I am trying to show related posts based on tags. I have everything working fine but when I load the detail view in the browser I get an error saying type object 'Post' has no attribute 'published' I have posted my codes below.

Model:

class Post(models.Model):
    """docstring for Post."""
    STATUS_CHOICES = (
        ('drafts', 'Draft'),
        ('published', 'Published'), )
    user = models.ForeignKey(settings.AUTH_USER_MODEL, default=1) #blank=True, null=True)#default=1
    title = models.CharField(max_length = 120)
    slug = models.SlugField(unique= True)
    draft = models.BooleanField(default = False)
    publish = models.DateField(auto_now=False, auto_now_add=False)
    content = models.TextField()
    tags = TaggableManager()
    status = models.CharField(max_length=10,choices=STATUS_CHOICES, default='published')
    updated = models.DateTimeField(auto_now=True, auto_now_add=False)
    timestamp = models.DateTimeField(auto_now=False, auto_now_add=True)

View:

def view(request, slug =None):
    instance = get_object_or_404(Post, slug =slug)
    if instance.draft or instance.publish > timezone.now().date():
        redirect(index)
    #content_type = ContentType.objects.get_for_model(Post)
    #obj_id = instance.id
    initial_data = {
            "content_type": instance.get_content_type,
            "object_id": instance.id
    }
    form = CommentForm(request.POST or None, initial=initial_data)
    if form.is_valid():
        #print  (form.cleaned_data)
        c_type = form.cleaned_data.get("content_type")
        content_type = ContentType.objects.get(model= c_type)
        obj_id = form.cleaned_data.get("object_id")
        c_content =form.cleaned_data.get("content")
        parent_obj = None
        try:
            parent_id = int(request.POST.get("parent_id"))
        except Exception as e:
            parent_id = None

        if parent_id:
            parent_query = Comment.objects.filter(parent__id= parent_id)
            if parent_query.exists():
                parent_obj = parent_query.first()

        new_comment, created = Comment.objects.get_or_create(
                user = request.user,
                content_type = content_type,
                object_id = obj_id,
                content = c_content,
                parent = parent_obj,

                )
        return HttpResponseRedirect(new_comment.content_object.get_absolute_url())


    comments = instance.comments
    # List of similar posts
    post_tags_ids = instance.tags.values_list('id', flat=True)
    similar_posts = Post.published.filter(tags__in=post_tags_ids).exclude(id=instance.id)
    similar_posts = similar_posts.annotate(same_tags=Count('tags')).order_by('-same_tags','-publish')[:4]
    context = {
    #"objects": query,
    "instance": instance,
    "comments": comments,
    "form": form,
    'similar_posts': similar_posts
    }
    template = 'view.html'
    return render(request,template,context)

addition codes would be added on request. Thanks in advance.

Answer 1

If I correctly understand then you have a typographical mistake

similar_posts = Post.published.filter(tags__in=post_tags_ids)
                                     .exclude(id=instance.id)

The line above should be

similar_posts = Post.objects.filter(tags__in=post_tags_ids)
                                     .exclude(id=instance.id)

Also If you meant use field publish then it can only be used in queryset args not as a Related Object attribute

Answer 2

Add the following attributes to the Post class:

class Post(models.Model):
   # ...
   objects = models.Manager() # The default manager.
   published = PublishedManager() # Our custom manager.

and

posts = Post.published.all()