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Python Django Basics Test Time Django TDD

'karaoke.song' is not a registered namespace

I have no idea why this test fails:

ERROR: test_song_list_view (songs.tests.ViewTests)

The song_list view should:

Traceback (most recent call last):
File "/usr/local/pyenv/versions/3.5.0/lib/python3.5/site-packages/django/core/urlresolvers.py", line 586, in reverse
extra, resolver = resolver.namespace_dict[ns]
KeyError: 'karaoke.song'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/usr/local/pyenv/versions/3.5.0/lib/python3.5/site-packages/django/template/defaulttags.py", line 507, in render
current_app=current_app)
File "/usr/local/pyenv/versions/3.5.0/lib/python3.5/site-packages/django/core/urlresolvers.py", line 596, in reverse
key)
django.core.urlresolvers.NoReverseMatch: 'karaoke.song' is not a registered namespace ...

I have been trying long time and gave up. Please help.

songs/models.py
from django.db import models

class Performer(models.Model):
  name = models.CharField(max_length=255)

  def __str__(self):
    return self.name

class Song(models.Model):
  title = models.CharField(max_length=255)
  artist = models.CharField(max_length=255)
  performer = models.ForeignKey(Performer)
  length = models.IntegerField(default=0)

  def __str__(self):
    return self.title + " by " + self.artist
songs/views.py
from django.shortcuts import render, get_object_or_404
from .models import Song, Performer

def performer_detail(request, pk):
  performer = get_object_or_404(Performer, pk=pk)
  return render(request, 'songs/performer_detail.html', {'performer': performer})

def song_list(request):
  songs = Song.objects.all()
  return render(request, 'songs/song_list.html', {'songs': songs})

def song_detail(request, performer_pk, song_pk):
  song = get_object_or_404(Song, performer_id=performer_pk, pk=song_pk)
  return render(request, 'songs/song_detail.html', {'song': song})
songs/templates/songs/performer_detail.html
{% extends 'base.html' %}

{% block title %}{{ performer }}{% endblock %}

{% block content %}
<h2>{{ performer }}</h2>
{% endblock %}
Chris Freeman
Chris Freeman
Treehouse Moderator 68,454 Points

Should have asked earlier: are you running on a local system or in the Workspaces?

If in the workspaces can you create a Snapshot (camera icon in upper right) of your workspace and post the link?

4 Answers

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,454 Points

Found the issue. In karaoke/songs/templates/songs/song_list.html there is a reference to the namespace song:

{% extends 'base.html' %}

{% block title %}Upcoming Songs{% endblock %}

{% block content %}
<h2>Upcoming Songs</h2>

<ul>
    {% for song in songs %}
    <li>
      <a href="{% url 'songs:detail' pk=song.pk %}">{{ song }}</a>
      performed by 
      {# In THIS url, song:performer should be songs:performer #)
      <a href="{% url 'song:performer' pk=song.performer.pk %}">{{ song.performer }}</a>
    </li>
    {% endfor %}
</ul>
{% endblock %}

Thank you for a challenging question! Happy coding!

That's it, thanks!

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,454 Points

In one of your templates I am guessing you have "karaoke.song" as a {% url %} argument instead of "karaoke:song" (using a colon to indicate the namespace karaoke. See URL namespaces docs

hmm.. I fail to see "karaoke.song" as a {% url %} arg in my template files below.

..\karaoke\templates\base.html:

    6      <body>
    7          <h1>Django Karaoke!</h1>
    8:         <p><a href="{% url 'songs:list' %}">Upcoming Songs</a></p>
    9      </body>
   10  </html>

..\karaoke\templates\songs\song_detail.html:

    7  
    8  <p>By {{ song.artist }}</p>
    9: <p>Sung by <a href="{% url 'songs:performer' pk=song.performer.pk %}">{{ song.performer }}</a></p>
   10  {% endblock %}

..\karaoke\templates\songs\song_list.html:

    9      {% for song in songs %}
   10      <li>
   11:     <a href="{% url 'songs:detail' pk=song.pk %}">{{ song }}</a> performed by <a href="{% url 'songs:performer' pk=song.performer.pk %}">{{ song.performer }}</a>
   12      </li>
   13      {% endfor %}

I'm still in dismay. Please help.

[MOD: added ``` markdown formatting -cf]

Chris Freeman
Chris Freeman
Treehouse Moderator 68,454 Points

TJ, Can you please post your karaoke/urls.py and your songs/urls.py? Thanks.

Hi Chris, Thank you for taking a look at these.

karaoke/urls.py:

"""karaoke URL Configuration

The `urlpatterns` list routes URLs to views. For more information please see:
    https://docs.djangoproject.com/en/1.8/topics/http/urls/
Examples:
Function views
    1. Add an import:  from my_app import views
    2. Add a URL to urlpatterns:  url(r'^$', views.home, name='home')
Class-based views
    1. Add an import:  from other_app.views import Home
    2. Add a URL to urlpatterns:  url(r'^$', Home.as_view(), name='home')
Including another URLconf
    1. Add an import:  from blog import urls as blog_urls
    2. Add a URL to urlpatterns:  url(r'^blog/', include(blog_urls))
"""
from django.conf.urls import include, url
from django.contrib import admin
from django.contrib.staticfiles.urls import staticfiles_urlpatterns

from . import views

urlpatterns = [
    url(r'^songs/', include('songs.urls', namespace='songs')),
    url(r'^admin/', include(admin.site.urls)),
    url(r'^$', views.home, name='home'),
]

urlpatterns += staticfiles_urlpatterns()

songs/urls.py:

from django.conf.urls import url

from . import views

urlpatterns = [
    url(r'performer/(?P<pk>\d+)/$', views.performer_detail, name='performer'),
    url(r'song/(?P<pk>\d+)/$', views.song_detail, name='detail'),
    url(r'^$', views.song_list, name='list'),
]

[MOD: adjusted formatting -cf]]

Chris Freeman
Chris Freeman
Treehouse Moderator 68,454 Points

I don't see any issue with the url files, they are the same as mine.

I am running both local and the workspace. Here's a link to the workspace: https://w.trhou.se/wmlfzbpgm2

TJ