error while clicking the send button 'post_detail' is not a valid view function or pattern name

Question

while iam adding comment option to my django project i came up with these error

here this comment is the comment i gave through the admin page and it get repeating again and again and also when i try to add a new comment as user when i click the send button it shows the following error and the page of form of comment is: and the views.py code is:

from .forms import PostForm, CommentForm
from django.contrib import messages
from django.contrib.auth.mixins import LoginRequiredMixin
from django.urls import reverse_lazy
from django.http import Http404
from django.views import generic
from django.contrib.auth.decorators import login_required
from .forms import PostForm, CommentForm
from .models import Post, Comment
from django.shortcuts import render, get_object_or_404, redirect



# pip install django-braces
from braces.views import SelectRelatedMixin

from . import forms
from . import models

from django.contrib.auth import get_user_model
User = get_user_model()


class PostList(SelectRelatedMixin, generic.ListView):
    model = models.Post
    select_related = ("user", "group")


class UserPosts(generic.ListView):
    model = models.Post
    template_name = "posts/user_post_list.html"

    def get_queryset(self):
        try:
            self.post_user = User.objects.prefetch_related("posts").get(
                username__iexact=self.kwargs.get("username")
            )
        except User.DoesNotExist:
            raise Http404
        else:
            return self.post_user.posts.all()

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context["post_user"] = self.post_user
        return context


class PostDetail(SelectRelatedMixin, generic.DetailView):
    model = models.Post
    select_related = ("user", "group")

    def get_queryset(self):
        queryset = super().get_queryset()
        return queryset.filter(
            user__username__iexact=self.kwargs.get("username")
        )


class CreatePost(LoginRequiredMixin, SelectRelatedMixin, generic.CreateView):
    # form_class = forms.PostForm
    fields = ('message','group')
    model = models.Post

    # def get_form_kwargs(self):
    #     kwargs = super().get_form_kwargs()
    #     kwargs.update({"user": self.request.user})
    #     return kwargs

    def form_valid(self, form):
        self.object = form.save(commit=False)
        self.object.user = self.request.user
        self.object.save()
        return super().form_valid(form)


class DeletePost(LoginRequiredMixin, SelectRelatedMixin, generic.DeleteView):
    model = models.Post
    select_related = ("user", "group")
    success_url = reverse_lazy("posts:all")

    def get_queryset(self):
        queryset = super().get_queryset()
        return queryset.filter(user_id=self.request.user.id)

    def delete(self, *args, **kwargs):
        messages.success(self.request, "Post Deleted")
        return super().delete(*args, **kwargs)




def add_comment_to_post(request, pk):
        post = get_object_or_404(Post, pk=pk)
        if request.method == "POST":
            form = CommentForm(request.POST)
            if form.is_valid():
                comment = form.save(commit=False)
                comment.post = post
                comment.save()
                return redirect('post_detail', pk=post.pk)
        else:
            form = CommentForm()
            return render(request, 'posts/add_comment_to_post.html', {'form': form})

Answer 1

From your implementation of PostDetial 's get_queryset method, I can see that you need to pass a username value when calling the redirect of post_detail url name. Like this:

return redirect('posts:single', pk=post.pk, username=post.user.username)

Update

Apparantly you do not have a url pattern named post_detail , instead it is named as single .