Django URL Reverse Issue: 'course_detail' Pattern Not Found with Supplied Arguments

Courses
1

Hey everyone! I’m new to Django and I’m running into a URL reversing problem while building my website. I followed a tutorial to develop a blog, but when I tried modifying the project for my own site, I encountered a puzzling error.

The error message reads:

Reverse for 'course_detail' with arguments '()' and keyword arguments '{u'cd': ''}' not found. 1 pattern(s) tried: ['course/(?P<cd>\d+)/$']

I never expected to see the “u’” prefix on the parameter ‘cd’ as I didn’t use it in my earlier project. I’ve searched through my code and can’t identify the source of this anomaly.

Below is a snippet from my urls file:

from django.conf.urls import url
from . import views

urlpatterns = [
    url(r'^$', views.lesson_list, name='lesson_list'),
    url(r'^lesson/(?P<lesson_id>\d+)/$', views.lesson_detail, name='lesson_detail'),
]

And part of the relevant template:

<h2><a href="{% url 'lesson_detail' lesson_id=lesson.lesson_id %}">{{ lesson.lesson_name }}</a></h2>

Can anyone help me figure out what I’m doing wrong? Thanks a lot in advance for your assistance!

2

yo buddy, ive seen this before. check ur views.py file. maybe u accidentally used ‘course_detail’ instead of ‘lesson_detail’ somewhere. also, try clearing ur cache n restarting the server. sometimes django gets confused w/ old stuff hanging around. good luck man, youll figure it out!

3

I recently ran into a similar issue, and in my case the problem turned out to be a mismatch in variable naming. It helped to double-check your view function and your URL configuration to make sure you’re using the same parameter name consistently—in your template, view, and urls.py. The error message mentioning ‘course_detail’ instead of ‘lesson_detail’ suggests there might still be an outdated reference in your code. I recommend testing the URL reversal manually in your Django shell using reverse(‘lesson_detail’, args=[1]). That should help isolate whether it’s a configuration error or an issue with how the context is being passed to the template. Also, verifying that your app URLs are included correctly in the project’s main urls.py could help resolve the problem.

4

Hey there, EnthusiasticPainter7! Welcome to the wonderful world of Django! :blush:

It looks like you’re dealing with a bit of a head-scratcher there. I’ve run into similar issues before, and they can be quite frustrating. Have you double-checked that your view function matches the URL pattern you’ve defined?

I notice you’re using ‘lesson_detail’ in your template, but your error message mentions ‘course_detail’. Could there be a mismatch somewhere in your code? Maybe you’ve got an old reference to ‘course_detail’ hiding somewhere?

Also, that ‘u’ prefix is interesting. It typically shows up in Python 2 to indicate Unicode strings. Are you sure you’re running Python 3? Might be worth checking your Python version just to rule that out.

Have you tried using the ‘name’ parameter in your url patterns? Something like:

url(r'^lesson/(?P<lesson_id>\d+)/$', views.lesson_detail, name='lesson_detail'),

This can sometimes help Django find the right URL more easily.

Oh, and one more thing - how are you passing the lesson_id in your view? Make sure it matches what you’re expecting in the URL pattern.

Let me know if any of this helps or if you need more ideas. Debugging can be a pain, but we’ll figure it out together! :muscle: