Django - NoReverseMatch Error even with correct parameters (no namespacing)-CodePudding

I'm trying to create an app that stores problems (specifically math problems), and displays them to the user. I haven't add much of the functionality that I want to yet, and as I'm fairly new to Django, I have been following along with the Django Tutorial project, and changing it according to my needs. However, I'm encountering a NoReverseMatch error even though I seem to be passing in the correct parameters. My code is below.

models.py

import imp
from django.db import models
from django.urls import reverse
import uuid

# Create your models here.

class Source(models.Model):
    '''Model that represents the source of a problem (e.g. AMC, AIME, etc.)'''
    problem_source = models.CharField(max_length=20)
    problem_number = models.PositiveSmallIntegerField()

    def __str__(self):
        '''toString() method'''
        return f'{self.problem_source} #{self.problem_number}'

class Topic(models.Model):
    '''Model that represents the topic of a problem (e.g. Intermediate Combo)'''
    problem_topic = models.CharField(max_length=50)
    problem_level = models.CharField(max_length=15)

    def __str__(self):
        return f'{self.problem_level} {self.problem_topic}'

class Problem(models.Model):
    '''Model that represents each problem (e.g. AIME #1, AMC #11, etc.)'''

    id = models.UUIDField(primary_key=True, default=uuid.uuid4)
    source = models.OneToOneField(Source, on_delete=models.RESTRICT, null=True, unique=True)
    problem_text = models.TextField()
    topic = models.ManyToManyField(Topic)

    def __str__(self):
        """String for representing the Model object."""
        return f'{self.source}'

    def get_absolute_url(self):
        """Returns the url to access a detail record for this book."""
        return reverse('problem-detail', args=[str(self.id)])

urls.py

from django.urls import path
from . import views

urlpatterns = [
    path('', views.index, name='index'),
    path('problems/', views.ProblemListView.as_view(), name='problems'),
    path('problem/<int:pk>', views.ProblemListView.as_view(), name='problem-detail'),
]

views.py

import imp
from django.shortcuts import render

# Create your views here.

from .models import Problem, Source, Topic

def index(request):
    '''View function for home page of site'''

    # generate counts of the main objects

    num_problems = Problem.objects.all().count()

    context = {
        'num_problems': num_problems,
    }

    return render(request, 'index.html', context=context)

from django.views import generic

class ProblemListView(generic.ListView):
    model = Problem

class ProblemDetailView(generic.DetailView):
    model = Problem

Links to my HTML files are below:
base_generic.html: link
problem_list.html: link
problem_detail.html: link

My workspace is structured as follows:

trivial
    catalog
        migrations
        static/css
            styles.css
        templates
            catalog
                problem_detail.html
                problem_list.html
            base_generic.html
            index.html
        __init.py
        admin.py
        apps.py
        models.py
        tests.py
        urls.py
        views.py
    trivial
        __init__.py
        asgi.py
        settings.py
        urls.py
        wsgi.py
    db.sqlite3
    manage.py

I have read other StackOverflow posts, but none seem to apply to my situation. Also, in problem_list.html, if the value in the href link is Problem.get_absolute_url, the site will load, but clicking the link for "all problems" will lead back to the same page. But, if I put prob.get_absolute_url in the href link, I get a NoReverseMatch error.

Here is the exact error that I am getting:

NoReverseMatch at /catalog/problems/

Reverse for 'problem-detail' with arguments '('41b936f7-3c08-4fb9-a090-2d466348d34d',)' not found. 1 pattern(s) tried: ['catalog/problem/(?P<pk>[0-9] )\\Z']

Request Method:     GET
Request URL:    http://127.0.0.1:8000/catalog/problems/
Django Version:     4.0.2
Exception Type:     NoReverseMatch
Exception Value:    

Reverse for 'problem-detail' with arguments '('41b936f7-3c08-4fb9-a090-2d466348d34d',)' not found. 1 pattern(s) tried: ['catalog/problem/(?P<pk>[0-9] )\\Z']

Django is telling me that the error stems from calling prob.get_absolute_url in problem_list.html

CodePudding user response：

The problem is that your id on the Problem model is a UUID, but your URL pattern is expecting an integer value as the pk - because you have prefixed the named pattern with int::

path('problem/<int:pk>', views.ProblemListView.as_view(), name='problem-detail'),

It should work if you change it to:

path('problem/<uuid:pk>', views.ProblemListView.as_view(), name='problem-detail'),