Django - /blog/cat1 'NoneType' 对象的 AttributeError 没有属性 'views'

Question

希望能得到一些帮助理解，每当我尝试按类别获取博客文章时，我都会收到以下错误： /blog/cat1 'NoneType' 对象的 AttributeError 没有属性 'views' “cat1”是我在 django 管理面板中创建用于测试的类别名称

这是我的 models.py 文件

from django.db import models
from django.contrib.auth.models import User
from django.utils.timezone import now
from ckeditor_uploader.fields import RichTextUploadingField

# Create your models here.
class Post(models.Model):
    sno = models.AutoField(primary_key=True)
    title = models.CharField(max_length=255)
    content = RichTextUploadingField()
    thumbnail = models.ImageField(upload_to='featured_image/%Y/%m/%d/')
    categories = models.ManyToManyField('Category', related_name='posts')
    author = models.CharField(max_length=15)
    slug = models.CharField(max_length=255)
    views = models.IntegerField(default=0)
    timeStamp = models.DateTimeField(blank=True)

    def __str__(self):
        return self.title + ' by ' + self.author
    
class Category(models.Model):
    name = models.CharField(max_length=50)

    class Meta:
        verbose_name_plural = "categories"

    def __str__(self):
        return self.name


class BlogComment(models.Model):
    sno = models.AutoField(primary_key=True)
    comment = models.TextField()
    user = models.ForeignKey(User, on_delete=models.CASCADE)
    post = models.ForeignKey(Post, on_delete=models.CASCADE)
    parent = models.ForeignKey('self', on_delete=models.CASCADE, null=True)
    timestamp = models.DateTimeField(default=now)
    def __str__(self):
        return self.comment[0:13] + "..." + "by " + self.user.username

视图.py

from django.shortcuts import render, redirect, get_object_or_404
from blog.models import Post, BlogComment, Category
from django.contrib import messages
from blog.templatetags import extras
from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger
import socket

# Create your views here.
def blogHome(request, tag_slug=None):
    allPosts = Post.objects.all().order_by("-timeStamp")
    # context = {'allPosts': allPosts}
    paginator = Paginator(allPosts, 5)
    page = request.GET.get('page')
    try:
        allPosts = paginator.page(page)
    except PageNotAnInteger:
        allPosts = paginator.page(1)
    except EmptyPage:
        allPosts = paginator.page(paginator.num_pages)

    return render(request, 'blog/blogHome.html', {'allPosts': allPosts, page:'pages'})

def blogCategory(request, pk):
    category = get_object_or_404(Category, pk=pk)
    return render(request, "blog/blogCategory.html", {'category': category})

def blogPost(request, slug):
    post = Post.objects.filter(slug=slug).first()
    post.views = post.views+1
    post.save()

    # comments
    comments = BlogComment.objects.filter(post=post, parent=None)
    replies = BlogComment.objects.filter(post=post).exclude(parent=None)
    replyDict = {}
    for reply in replies:
        if reply.parent.sno not in replyDict.keys():
            replyDict[reply.parent.sno] = [reply]
        else:
            replyDict[reply.parent.sno].append(reply)

    context = {'post': post, 'comments': comments, 'user': request.user, 'replyDict': replyDict}
    return render(request, 'blog/blogPost.html', context)

def postComment(request):
    if request.method == 'POST':
        comment = request.POST.get('comment')
        user = request.user
        postSno = request.POST.get('postSno')
        post = Post.objects.get(sno=postSno)
        parentSno = request.POST.get('parentSno')

        # new comment
        if parentSno == "":
            comment = BlogComment(comment=comment, user=user, post=post)
            comment.save()
            messages.success(request, 'Your comment has been posted successfully')
            
        # replies
        else:
            parent = BlogComment.objects.get(sno=parentSno)
            comment = BlogComment(comment=comment, user=user, post=post, parent=parent)
            comment.save()
            messages.success(request, 'Your reply has been posted successfully')

    return redirect(f'/blog/{post.slug}')

网址.py

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

urlpatterns = [
    path('postComment', views.postComment, name='postComment'),
    path('', views.blogHome, name='blogHome'),
    path('<str:slug>', views.blogPost, name='blogPost'),
    path('category/<category>/', views.blogCategory, name='blogCategory'),
]

这是我的blogCategory.html模板（如果我错误地渲染模板，请也帮助我）

{% extends "base.html" %}

{% block title %} Categories {% endblock title %}
{% block blogactive %} active {% endblock blogactive %}
{% block body %}
<div class="container my-4">
    <h2>Related Articles:</h2>
    {% if posts == posts %}
    <p>No such Category</p>
    Your search did not match any documents.<br>
    Suggestions: <br>
    <ul>
        <li>Make sure that all words are spelled correctly.</li>
        <li>Try different keywords.</li>
        <li>Try more general keywords.</li>
        <li>Try fewer keywords.</li>
    </ul>

    {% endif %}

    {% for category in post.categories.all %}

        <div class="card mb-3">
            <div class="card-body">
                <div class="row g-0">
                    <div class="col-md-4">
                        <div class="ratio ratio-16x9">
                        <!-- featured image --> 
                            <img src="{{ post.thumbnail.url }}" class="rounded featured-image-list" alt="{{post.title}}">
                        </div>
                    </div>
                    <div class="col-md-7 ps-md-3 pt-3 pt-md-0 d-flex flex-column">
                            <h2 class="card-title h3">
                                <a href="{{ post.slug }}">{{ post.title }}</a>
                            </h2>
                            <div class="text-muted">
                                <small>
                                    Published {{ post.timeStamp }} by <strong>{{ post.author }}</strong>
                                </small>
                            </div>
                            <p class="card-text mb-auto py-2">{{ post.content|safe|striptags|truncatechars:300 }}</p>
                            <div>
                                <a href="{{ post.slug }}" class="btn btn-primary">Read more</a> | Categories:
                                {% for category in post.categories.all %}
                                    <a href="{{ category.name }}">
                                        {{ category.name }}
                                    </a>
                                {% endfor %}
                            </div>
                    
                    </div>
                </div>
            </div>
        </div>


    {% endfor %}

</div>
{% endblock body %}

我的期望：当任何人点击标签时，他们应该看到该类别的博客文章

Answer 1

引发错误，因为

post = Post.objects.filter(slug=slug).first()

返回 None 所以...

尝试使用下面的代码片段

post = Post.objects.filter(slug=slug).first()
if post is not None:
   # Perform actions with the retrieved post
   post.views = post.views + 1
   post.save()