How to display nested categories?

Question

Django

There is a model

class Category(models.Model):
    name = models.CharField('Наименование', max_length=100)
    slug = models.SlugField(max_length=160, unique=True)
    parent = models.ForeignKey(
        'self', verbose_name='Родитель', on_delete=models.SET_NULL, blank=True, null=True, related_name='children'
    )

templatetags

@register.simple_tag()
def get_categories():
    return Category.objects.all()

I output, respectively, all categories are displayed together with their children. You can add in templatetags .filter(parent__isnull=True), but how then to display child categories?

{% get_categories as categories %}
{% for category in categories %}
<a>{ category.name }</a>
{% endfor %}

Answer 1

Recursively. Google django-mptt and either use or steal the implementation from there