Reverse for url with arguments not found in Django

Question

Error: Reverse for 'task_list_by_tag' with arguments '('оаип_1',)' not found. 1 pattern(s) tried: ['tag/(?P<tag_slug>[-a-zA-Z0-9_]+)/\Z']

views.py

def index(request, tag_slug=None):
    task_list = Task.objects.all()
    
    tag = None

    if tag_slug:
        tag = get_object_or_404(Tag, slug=tag_slug)
        task_list = task_list.filter(tags__in=[tag])

    paginator = Paginator(task_list, 2)
    page_number = request.GET.get('page', 1)
    try:
        tasks = paginator.page(page_number)

    context = {"tasks":tasks, 'tag':tag}

    return render(request, 'main/index.html', context)

urls.py

app_name = 'main'
...
path('tag/<slug:tag_slug>/', views.index, name = "task_list_by_tag"),

index.html

{% for tag in task.tags.all %}
       <a href="{% url "main:task_list_by_tag" tag.slug %}">
           {{ tag.name }}
       </a>
{% if not forloop.last %}, {% endif %}
{% endfor %}

I tried to fix that problem:

1)

<a href="{% url "main:task_list_by_tag" tag_slug=tag.slug %}">

return the error: Reverse for 'task_list_by_tag' with keyword arguments '{'tag_slug': 'оаип_1'}' not found. 1 pattern(s) tried: ['tag/(?P<tag_slug>[-a-zA-Z0-9_]+)/\Z']

2)

`<a href="{% url "main:task_list_by_tag" slug=tag.slug %}">`

Reverse for 'task_list_by_tag' with keyword arguments '{'slug': 'оаип_1'}' not found. 1 pattern(s) tried: ['tag/(?P<tag_slug>[-a-zA-Z0-9_]+)/\Z']

Answer 1

Using <a href="{% url "main:task_list_by_tag" tag.slug %}"> is perfectly fine as Django has found the correct URL mentioned in:

Error: Reverse for 'task_list_by_tag' with arguments '('оаип_1',)' not found. 1 pattern(s) tried: ['tag/(?P<tag_slug>[-a-zA-Z0-9_]+)/\Z']

But as per Django documentation, you can only use "ASCII letters or numbers, plus the hyphen and underscore characters" for slugs:

slug - Matches any slug string consisting of ASCII letters or numbers, plus the hyphen and underscore characters. For example, building-your-1st-django-site.

Make sure that your slug consists only of these characters and not Cyrillic, as you are doing now. Otherwise, change your URL dispatcher to str.