Django URLResolver error

There are many errors that come when we create a project in Django. In this article, we will learn how to resolve such error “URLResolver error”.

What is URLResolver Error in Django?

Url Resolver error in Django pops out when there is a mistake in your URL patterns configurations. This can be caused by incorrect URL patterns, view function mismatches, namespace conflicts, circular imports, middleware ordering, or server configuration problems.

Syntax: TypeError: ‘URLResolver’ object is not subscriptable

Causes of URLResolver Error in Django

Following are the reasons or common mistakes that can cause this error.

• Typo Error: While creating the URLs and views you may make spelling mistakes or any typo may be there.
• Incorrect URL Path: In templates, an incorrect URL path is mentioned.
• App specific: if you have created many apps then from the base project URL to a specific app the request not moving forward.

Approaches to Solve URLResolver Error in Django

This error can be solved by debugging the code. Start checking if we have made any typing mistakes. fixing and checking the path, for each unique URL path there should be a view present. And correctly being used if you are rendering templates. So first we look for the reason for what we did wrong and then try to solve it.

Checking if there are any typos.

Verify that you have created all the url’s correctly and that the same mentioned views were also created. Check for typos and letter cases also. I have shown a example of routing the request from baURLse folder to app folder. It is having all the necessary things to get rid of this problem.

Python3

from django.contrib import admin
from django.urls import path, include
from . import views
from django.conf import settings
from django.conf.urls.static import static

urlpatterns = [
    path('admin/', admin.site.urls),
    path('', views.home, name="home"),
    path('dashboard/', include('Dashboard.urls')),
]
+ static(settings.STATIC_URL, document_root=settings.STATIC_ROOT)

Checking for URL Paths mentioned in project.

To get redirect on another url we use url sytax in jinja template. Check if you have mentioned the path is correct and you have created the url for the same.

HTML

{% extends 'dashboard.html' %}
{% block content %}

<div class="container mt-5 p-5 border">
  {% include 'includes/alerts.html' %}
  <form action="{% url 'add_playlist' %}" method="POST"
        class="form-search d-flex align-items-stretch mb-3"
        data-aos="fade-up" data-aos-delay="200">
    {% csrf_token %}
    <input type="text" name="url" class="form-control"
           placeholder="https://www.youtube.com/playlist?list=Enf28pe9fsdFH1.">
    <div>
      <button type="submit" class="btn btn-primary">Add</button>
    </div>
    </form>
</div>

{% endblock content %}

Checking File Imports

You will have to import the views and urls in required files. so make sure you are following correct way to import them.

Python3

from django.contrib import admin
from django.urls import path, include
from . import views     # HERE

urlpatterns = [
    path('', views.dashboard, name="Dashboard"),
    path('add_playlist/', views.add_playlist, name="add_playlist"),
]

Checking for namespaces clashes

There should not be same names given for the 2 URLs. This may lead to error so fix it.

Python3

from django.contrib import admin
from django.urls import path
from . import views

urlpatterns = [
    path('login/', views.login, name='register'),
    path('logout/', views.logout, name='register'),
    path('signup/', views.signup, name='signup'),
]

Restart the Server

If from the long time you didn’t restarted your server and continuously working. Sometimes it does not reflect our restarts automatically. Just stop the server and restart it.

CTRL + C
python manage.py runserver

Solutions of Django URLResolver error

Add ROOT_URLCONF Setting

This is the important configuration setting need to define in settings.py file that specifies base directory where you have defined the urls that will route the request in your project apps.

ROOT_URLCONF = 'myproject.urls'

Fix URL Patterns and Views

Hit below command “python manage.py check app_name“. after hitting this command Django will check if there are any issues are there in mentioned app name. if there is any it will show the error line number with the problem. The next step would be go and fix the problem at the indicated place.

Add Static/Media files settings

if you are using static urls or media files urls in your project. for this purpose you need to have this line in your root urls.file.

  from django.conf import settings
  from django.conf.urls.static import static
  urlpatterns = [
      # ... the rest of your URLconf goes here ... 
  ] 
urlpattern += static(settings.STATIC_URL, document_root=settings.STATIC_ROOT)
urlpattern += static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

Clear Cache And Restart the Server

Try below commands to clear out the cache and restart the server.

The ‘python manage.py flush' command is used in Django to reset the database by removing all data from it. It is a management command provided by Django’s management system and can be executed in the terminal.

python manage.py flush

Hope, you may find this article helpful. I will update the article when there will be more solutions available for this.