python - Django template failling despite my effort to learn it -

categories.html # want called categoryview.as_view() never works. howevwer index.html works have hardcoded link follows within index.html. although index.html extends base.html outputing url. edit: avoid confusion available in index.html template guess should work shows following error index page not found (404)

<li><a href="{% url 'all_categories' %}">all</a></li> 

from root directory when type http://127.0.0.1:8000 works want http://127.0.0.1:8000/cartegories/(index.html or categories.html) assume index.html or categories.html not visible when typed, fine.

i can’t believe taking me 12hours possible intuitive tweaking still can’t work. please advise doing wrong. in essense outputing hellow world in categories.html later iterate through , list categories in blog… if hello world can’t work nothing will..

#posts urls.py django.conf.urls import include, url django.contrib import admin  .views import indexview, categoryview  urlpatterns = [     url(r'^$', indexview.as_view(), name='index'),     url(r'^all_categories$', categoryview.as_view(), name='all_categories'),      # stuff have tried  ]  #admin urls.py django.conf.urls import include, url django.contrib import admin  urlpatterns = [     url(r'^/', include('posts.urls', namespace="posts")),     url(r'^admin/', include(admin.site.urls)), ]  #views.py  django.shortcuts import render .models import post, comment, category, reply django.views import generic  class indexview(generic.listview):     template_name = 'posts/index.html'     context_object_name = 'posts'     model = post      def get_context_data(self, **kwargs):         context = super(indexview, self).get_context_data(**kwargs)         context['categories'] = category.objects.all()         return context  class categoryview(generic.listview):     template_name = 'posts/categories.html'     context_object_name = 'categories'     model = category   #modesl.py  class category(models.model):     category_name = models.charfield(max_length=200)      class meta:         verbose_name_plural = "categories"      def __str__(self):         return self.category_name      def get_absolute_url(self):         return reverse('all_categories')  class post(models.model):      title = models.charfield(max_length=200)     …     category = models.foreignkey(category)      def save(self, *args, **kargs):         if not self.id:             self.slug = slugify(self.title)          super(post, self).save(*args, **kargs)      def __str__(self):         return self.title 

changing order of urls in files solved problem. generally, order of main urls.py important readability / slash did trick

#admin urls.py django.conf.urls import include, url django.contrib import admin  urlpatterns = [     url(r'^/', include('posts.urls', namespace="posts")),     url(r'^admin/', include(admin.site.urls)),  ] 

also in post/url.py file added / @ end of regex

urlpatterns = [      url(r'^$', indexview.as_view(), name='index'),     url(r'^categories/$', categoryview.as_view(), name='all_categories'),  ] 

finally in template html read follows:

<li><a href="{% url 'posts:all_categories' %}">all</a></li>