我正在跟随@CoreyMSchafer的django教程。我在练习时遇到了错误，我找不到解决方法。
根据我的理解，它的问题与网址的逆转。但不能找出什么是错的
错误：/处无反向匹配
找不到参数为'（'，）'的'user-posts'的反转。已尝试1个模式：['用户/（？P[^/]+）$']
由于某种原因，错误是在base.html的头，我链接引导程序。
我还尝试删除该链接，然后它给出了相同的错误，但在base.html的第0行
views.py:

class UserPostListView(ListView):
    model = Post
    context_object_name = 'posts'
    template_name = 'blog/user_posts.html'

    paginate_by = 5

    def get_queryset(self):
        user = get_object_or_404(User, username=self.kwargs.get('username'))
        return Post.objects.all().filter(author= user).order_by('-date_posted')

urls.py 档案：

from django.urls import path, include
from .views import PostListView, PostDetailView, PostCreateView, PostUpdateView, PostDeletelView, UserPostListView
from . import views

urlpatterns = [
    path('',                        PostListView.as_view(),         name='blog-home'),
    path('user/<str:username>',    UserPostListView.as_view(),     name='user-posts'),
    path('post/<int:pk>/',          PostDetailView.as_view(),       name='post-detail'),
    path('post/new/',               PostCreateView.as_view(),       name='post-create'),
    path('post/<int:pk>/update/',   PostUpdateView.as_view(),       name='post-update'),
    path('post/<int:pk>/delete/',   PostDeletelView.as_view(),      name='post-delete'),
    path('about/',                  views.about,                    name='blog-about'),
]

用户_帖子.html：

{% if is_paginated %}

      {% if page_obj.has_previous %}
        <a class="btn btn-outline-info mb-4" href="?page=1">First</a>
        <a class="btn btn-outline-info mb-4" href="?page={{ page_obj.previous_page_number }}">Previous</a>
      {% endif %}

      {% for num in page_obj.paginator.page_range %}
        {% if page_obj.number == num %}
          <a class="btn btn-info mb-4" href="?page={{ num }}">{{ num }}</a>
        {% elif num > page_obj.number|add:'-3' and num < page_obj.number|add:'3' %}
          <a class="btn btn-outline-info mb-4" href="?page={{ num }}">{{ num }}</a>
        {% endif %}
      {% endfor %}

      {% if page_obj.has_next %}
        <a class="btn btn-outline-info mb-4" href="?page={{ page_obj.next_page_number }}">Next</a>
        <a class="btn btn-outline-info mb-4" href="?page={{ page_obj.paginator.num_pages }}">Last</a>
      {% endif %}

    {% endif %}
{% endblock content %}

home.html

{% if is_paginated %}

      {% if page_obj.has_previous %}
        <a class="btn btn-outline-info mb-4" href="?page=1">First</a>
        <a class="btn btn-outline-info mb-4" href="?page={{ page_obj.previous_page_number }}">Previous</a>
      {% endif %}

      {% for num in page_obj.paginator.page_range %}
        {% if page_obj.number == num %}
          <a class="btn btn-info mb-4" href="?page={{ num }}">{{ num }}</a>
        {% elif num > page_obj.number|add:'-3' and num < page_obj.number|add:'3' %}
          <a class="btn btn-outline-info mb-4" href="?page={{ num }}">{{ num }}</a>
        {% endif %}
      {% endfor %}

      {% if page_obj.has_next %}
        <a class="btn btn-outline-info mb-4" href="?page={{ page_obj.next_page_number }}">Next</a>
        <a class="btn btn-outline-info mb-4" href="?page={{ page_obj.paginator.num_pages }}">Last</a>
      {% endif %}

    {% endif %}

post_detail.html

{% extends "blog/base.html" %}
{% block content %}

    <article class="media content-section">
        <img class="rounded-circle article-img" src="{{ object.author.profile.image.url }}" alt="">
        <div class="media-body">
        <div class="article-metadata">
            <a class="mr-2" href="{% url 'user-posts' object.author.username %}">{{ object.author }}</a>
            <small class="text-muted">{{ object.date_posted|date:"M d, Y"}}</small>
            {% if object.author == user %}
                <div>
                    <a class="btn btn-secondary btn-sm mb-1" href="{% url 'post-update' object.id %}">Update</a>
                    <a class="btn btn-danger btn-sm mb-1" href="{% url 'post-delete' object.id %}">Delete</a>
                </div>
            {% endif %}
        </div>
        <h2 class="article-title">{{ object.title }}</h2>
        <p class="article-content">{{ object.content }}</p>
        </div>
    </article>

{% endblock content %}

base.html

{% extends "blog/base.html" %}
{% block content %}

    <article class="media content-section">
        <img class="rounded-circle article-img" src="{{ object.author.profile.image.url }}" alt="">
        <div class="media-body">
        <div class="article-metadata">
            <a class="mr-2" href="{% url 'user-posts' object.author.username %}">{{ object.author }}</a>
            <small class="text-muted">{{ object.date_posted|date:"M d, Y"}}</small>
            {% if object.author == user %}
                <div>
                    <a class="btn btn-secondary btn-sm mb-1" href="{% url 'post-update' object.id %}">Update</a>
                    <a class="btn btn-danger btn-sm mb-1" href="{% url 'post-delete' object.id %}">Delete</a>
                </div>
            {% endif %}
        </div>
        <h2 class="article-title">{{ object.title }}</h2>
        <p class="article-content">{{ object.content }}</p>
        </div>
    </article>

{% endblock content %}