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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def category_structure(category, site):
 """ A category structure. """

    return {'description': category.title,
            'htmlUrl': '%s://%s%s' % (
                PROTOCOL, site.domain,
                category.get_absolute_url()),
            'rssUrl': '%s://%s%s' % (
                PROTOCOL, site.domain,
                reverse('zinnia:category_feed', args=[category.tree_path])),
            # Useful Wordpress Extensions
            'categoryId': category.pk,
            'parentId': category.parent and category.parent.pk or 0,
            'categoryDescription': category.description,
            'categoryName': category.title}