Django音乐应用创建专辑后跳转详情页遇NoReverseMatch错误求助

问题场景 #

开发基于Django的音乐应用，期望创建新专辑后自动跳转到该专辑详情页，但使用reverse生成跳转链接时出现NoReverseMatch错误。

错误信息 #

Traceback (most recent call last):
  File "C:\Users\Sanath\anaconda3\lib\site-packages\django\core\handlers\exception.py", line 55, in inner
    response = get_response(request)
  File "C:\Users\Sanath\anaconda3\lib\site-packages\django\core\handlers\base.py", line 197, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "C:\Users\Sanath\anaconda3\lib\site-packages\django\views\generic\base.py", line 103, in view
    return self.dispatch(request, *args, **kwargs)
  File "C:\Users\Sanath\anaconda3\lib\site-packages\django\views\generic\base.py", line 142, in dispatch
    return handler(request, *args, **kwargs)
  File "C:\Users\Sanath\anaconda3\lib\site-packages\django\views\generic\edit.py", line 184, in post
    return super().post(request, *args, **kwargs)
  File "C:\Users\Sanath\anaconda3\lib\site-packages\django\views\generic\edit.py", line 153, in post
    return self.form_valid(form)
  File "C:\Users\Sanath\anaconda3\lib\site-packages\django\views\generic\edit.py", line 136, in form_valid
    return super().form_valid(form)
  File "C:\Users\Sanath\anaconda3\lib\site-packages\django\views\generic\edit.py", line 65, in form_valid
    return HttpResponseRedirect(self.get_success_url())
  File "C:\Users\Sanath\anaconda3\lib\site-packages\django\views\generic\edit.py", line 125, in get_success_url
    url = self.object.get_absolute_url()
  File "C:\Users\Sanath\Desktop\website\music\models.py", line 12, in get_absolute_url
    return reverse('music:detail',kwargs = {'pk' : self.pk})
  File "C:\Users\Sanath\anaconda3\lib\site-packages\django\urls\base.py", line 88, in reverse
    return resolver._reverse_with_prefix(view, prefix, *args, **kwargs)
  File "C:\Users\Sanath\anaconda3\lib\site-packages\django\urls\resolvers.py", line 828, in _reverse_with_prefix
    raise NoReverseMatch(msg)
django.urls.exceptions.NoReverseMatch: Reverse for 'detail' with keyword arguments '{'pk': 11}' not found. 1 pattern(s) tried: ['music/(?P<album_id>[0-9]+)/\\Z']

相关代码文件 #

urls.py #

from django.urls import path
from . import views

app_name = 'music'

urlpatterns = [
    #music/
    path('', views.index,name = 'index'),
    #music/71/
    path('<int:album_id>/', views.detail,name = 'detail'),
    path("register/",views.UserFormView.as_view(),name = 'register'),
    path("album/add/",views.albumcreate.as_view(),name = 'album-add'),

#url pattern for the view albumcreate
]

models.py #

from django.db import models
from django.urls import reverse
# Create your models here.
class album(models.Model):  #inherit from models.Model
    artist = models.CharField(max_length=250)                  #when migrated to db it will be a column with the same name automatically(here it is variables
    #charfield ,foreignkey is datatype 
    album_title =  models.CharField(max_length=500)   
    genre =  models.CharField(max_length=100) 
    album_logo = models.CharField(max_length=1000)  
    
    def get_absolute_url(self):
        return reverse('music:detail',kwargs = {'pk' : self.pk})
    #returns the detail page of the album we just created
                        
    def __str__(self):
        return self.album_title+'-'+self.artist#string representation of obj
class songs(models.Model):
    #songs needs to be part of an album
    album = models.ForeignKey(album,on_delete=models.CASCADE)
    #bts another column with unique id 1st album id 1 2nd album id 2 and so on
    #let pk of red = 1 then a song of that album will have fk as 1 so that they are linked
    #when ever we delete the ablum red all the songs in the album should be deleted hence             delete
    file_type= models.CharField(max_length=10) #mp3etc
    song_title =  models.CharField(max_length=250)
    
    def __str__(self):
        return self.song_title

views.py #

from django.http import HttpResponse
from .models import album
from django.shortcuts  import render,redirect
from django.contrib.auth import login,logout,authenticate
from django.http import Http404
from django.views.generic import View
from .forms import UserForm
from django.views.generic.edit import CreateView,UpdateView,DeleteView  # form to create new ,deleting,updating obj

def index(request):
    all_albums = album.objects.all()
    '''
    html =''

    for album1 in all_albums:
        path='/music/' + str(album1.id) + '/'
        html += '<a href="' + path + '">' + album1.album_title + '</a><br>'
      '''
    
   # template = loader.get_template('music/index.html')
    
    
    context = { 'all_albums': all_albums,
              }
    #return HttpResponse(template.render(context,request))
        #same thing as i did in alb1 code excpet i have done it though html file to prevent making a mess here
    return render(request,'music/index.html',context)
#same as above but using render shortcut which internally creates http response
    
def detail(request, album_id):
    try:
        alb = album.objects.get(pk=album_id)
    except album.DoesNotExist:
        raise Http404("album does not exist")
    return render(request,'music/detail.html',{ 'alb': alb})

        #not using context because we make use of only one album at one time and there ia no iterating over
    
class UserFormView(View):
    
    form_class = UserForm
    template_name = 'music/reg_form.html'
    
    def get(self,request):
        # when ever user requests from this form this fn is called
        #display a blank form
        
        form = self.form_class(None)  # nothing is present we have to input it
        return render(request,self.template_name,{form:form})
    #self. teemp name = where u want to return ,what html#
    def post(self,request):
        # when ever user submits the above  form this fn is called
        form = self.form_class(request.POST)  # what ever is entered in get is posted
        
        if form.is_valid():
            
            user= form.save(commit=False)  #storing itlocally not yet commited to db
            
            #cleaned normalized data(so that everyone uses the gemeral format and can be entered into the db properly
            
            username = form.cleaned_data['username']
            password = form.cleaned_data['password']
            user.set_password(password)  #method to set password we cannot do like user.password = 'raj' or = password
            user.save()
            
            
            # return user obj id credentials are correct
            
            user = authenticate(username=username,password = password)
            #what the above fun does it that it takes the username and pwd and chcecks with the db is they are an actual user
            
            if user is not None:  #for confirming above fn
                if user.is_active:
                    login(request,user)
                    #logged in to the website
                    #request.user.username
                    return redirect('music:index')
                
        return render(request,self.template_name,{form:form})
        

        
 #new classsthat creates the form view for get abs url fn   

class albumcreate( CreateView ): #using models and not by admin or shell queries but in the webpage itself   
    model = album
    fields = ['artist','album_title','genre','album_logo']
    #we havent specified template name cuz _form is the default file it is going to look at

问题原因 #

错误提示明确：reverse尝试用pk参数匹配detail视图，但URL模式里定义的参数名是album_id，两者不匹配，导致无法生成正确的跳转链接。

解决方法 #

两种可行修复方式，选其一即可：

方式一：修改get_absolute_url中的参数名 #

在models.py的album类里，把reverse的kwargs里的pk改成album_id：

def get_absolute_url(self):
    return reverse('music:detail', kwargs={'album_id': self.pk})

方式二：修改URL模式中的参数名 #

在urls.py里，把详情页的URL参数从album_id改成pk，同时同步修改views.py中detail函数的参数：

1. urls.py修改：

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

2. views.py修改：

def detail(request, pk):
    try:
        alb = album.objects.get(pk=pk)
    except album.DoesNotExist:
        raise Http404("album does not exist")
    return render(request,'music/detail.html',{ 'alb': alb})

两种方式都能解决参数不匹配问题，完成后创建新专辑即可正常跳转到详情页。

内容的提问来源于stack exchange，提问作者Sanath