Django| Reverse for 'user-posts' with arguments '('',)' not found. 1 pattern(s) tried: ['user/(?P<username>[^/]+)$']

Question

I am following django tutorial by @CoreyMSchafer. I got error while practicing i can't find solution to it.

According to my understanding its problem with reversing of url. but can't find out what is wrong

Error: NoReverseMatch at /

Reverse for 'user-posts' with arguments '('',)' not found. 1 pattern(s) tried: ['user/(?P[^/]+)$']

For some reason error is in head of base.html where I'm linking bootstrap.

I also tried removing that link then its giving same error but at line 0 of base.html

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 file:

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'),
]

user_posts.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 %}

Answer 1

url(r'^user/(?P<username>\w{0,50})/$', UserPostListView.as_view(), name='user-posts'),

just add it in your url
not this

path('user/<str:username>/', UserPostListView.as_view(),name='user-posts'),

Answer 2

I had the same question before. In your user_posts.html and base.html, change all the name of the 'object' stuff to 'post'. Example:

"object.author" -> "post.author", 
"object.title" -> "post.title", 
"object.author.username" -> "post.author.username"

that's a fix for me.

PS: Actually, u didn't post out the above mentioned part of the code. XD

Answer 3

In the urls.py file -

path('user/<str:username>/', UserPostListView.as_view(),name='user-posts'),

You forget to add backslash after <str:username>

Answer 4

i was watching the same course and i had the same problem. following two steps made this work for me: first make sure that you are referring to a correct HTML and then add a forward slash after your url like this:

path('user/<str:username>/', UserPostListView.as_view(), name='user-posts'),

if it didnt work for you use url instead of path like this:

url(r'^user/(?P<username>\w{0,50})/$', UserPostListView.as_view(), name='user-posts'),

Answer 5

I ran into the same issue as well.

I found that replacing the following line in blog/urls.py:

urlpatterns = [   

    path('user/<str:username>/', UserPostListView.as_view(), name='user-posts'),
]

with

from django.urls import path, re_path # <- don't forget this import


urlpatterns = [

    re_path(r'^user/(?P<username>\w{0,50})/$', UserPostListView.as_view(), name='user-posts'),
}

solved the issue.

Answer 6

I had the same error . My mistake was I misspelled 'object' in this line posts_detail.html

            <a class="mr-2" href="{%url 'user-posts' object.author.username %}">{{ object.author }}</a>

this might not be the reason for your error, but anyone else stuck with this error check for typos in your HTML files.

Answer 7

Replace post.author.username with post.author. It helped me.

Answer 8

url(r'^user/(?P<username>\w{0,50})/$', UserPostListView.as_view(), name='user-posts'),

just add it in your url
not this

path('user/<str:username>/', UserPostListView.as_view(),name='user-posts'),

Answer 9

I had the same question before. In your user_posts.html and base.html, change all the name of the 'object' stuff to 'post'. Example:

"object.author" -> "post.author", 
"object.title" -> "post.title", 
"object.author.username" -> "post.author.username"

that's a fix for me.

PS: Actually, u didn't post out the above mentioned part of the code. XD

Answer 10

In the urls.py file -

path('user/<str:username>/', UserPostListView.as_view(),name='user-posts'),

You forget to add backslash after <str:username>

Answer 11

i was watching the same course and i had the same problem. following two steps made this work for me: first make sure that you are referring to a correct HTML and then add a forward slash after your url like this:

path('user/<str:username>/', UserPostListView.as_view(), name='user-posts'),

if it didnt work for you use url instead of path like this:

url(r'^user/(?P<username>\w{0,50})/$', UserPostListView.as_view(), name='user-posts'),

Answer 12

I ran into the same issue as well.

I found that replacing the following line in blog/urls.py:

urlpatterns = [   

    path('user/<str:username>/', UserPostListView.as_view(), name='user-posts'),
]

with

from django.urls import path, re_path # <- don't forget this import


urlpatterns = [

    re_path(r'^user/(?P<username>\w{0,50})/$', UserPostListView.as_view(), name='user-posts'),
}

solved the issue.

Answer 13

I had the same error . My mistake was I misspelled 'object' in this line posts_detail.html

            <a class="mr-2" href="{%url 'user-posts' object.author.username %}">{{ object.author }}</a>

this might not be the reason for your error, but anyone else stuck with this error check for typos in your HTML files.

Answer 14

Replace post.author.username with post.author. It helped me.