How can I assign an url to a variable into a template? I've tried:
{% with url_news = url 'news' %}
and
{% with url 'news' as url_news %}
Use the as option of the url tag
{% url 'news' as the_url %}
{% if the_url %}
<a href="{{ the_url }}">Link to optional stuff</a>
{% endif %}
Note that when you use this syntax, it will fail silently if the url can't be resolved.