Django Sitemap клас для Articles

### sitemap.py

from articles.models import Article

class ArticlesListSitemap(Sitemap):
    changefreq = "weekly"
    priority = 0.9
    def lastmod(self, obj):
        return obj.publish_date
    def location(self, obj):
        d = obj.publish_date.strftime("%Y")
        return '/articles/' + d + '/' + obj.slug + '/'
    def items(self):
        return Article.objects.filter(is_active=True)