Splitting a list with django template tags
The more 'Django' way would be to do it in the view, as you are supposed to keep as much logic out of your template as possible. That being said, there is a ways you can do it through the template.
You can use the slice template tag if you already know how many are in the list. Let's assume you don't though.
The other method would be to just loop over it twice, and only display half you want. You would be going over the entire list though each time, so it might be expensive. It uses the forloop counter.
{% for item in items %}
#half list is calculated in your view. It is the items query /2
{% if forloop.counter < half_list %}
{% item.name %}
{% endif %}
{% endfor %}
{% for item in items %}
#half list is calculated in your view. It is the items query /2
{% if forloop.counter >= half_list %}
{% item.name %}
{% endif %}
{% endfor %}
A (slightly hacky) way to do this entirely in the template is to use widthratio template tag to work out the centre of the list and the with template tag to create temporary variables.
{% widthratio form.visible_fields|length 2 1 as visible_fields_centre %}
<div class="rows_form">
{% with ":"|add:visible_fields_centre as first_slice %}
{% for field in form.visible_fields|slice:first_slice %}
{{ field }}
{% endfor %}
{% endwith %}
</div>
<div class="rows_form">
{% with visible_fields_centre|add:":" as second_slice %}
{% for field in form.visible_fields|slice:second_slice %}
{{ field }}
{% endfor %}
{% endwith %}
</div>