Question

I have a Django model that looks like this:

class City(models.Model):
    country = models.CharField(max_length=50)
    city = models.CharField(max_length=50)
    population = models.IntegerField()

What I want to do in my template is print a list of cities grouped by country, like so:

Canada
  Calgary
  Montreal
  Toronto
Mexico
  Juarez
United States
  Atlanta
  Chicago
  Denver

I can order by country name easily enough, but I want to print the model’s country name as a heading only the first time I see it in the for loop. Is there a sane way to do this in Django?

Is there something I can do in the view or query to give the template a boolean value for “first occurrence”, or a clever way to do this in the template?

Answer 1

See regroup, you’d do something like this:

{% regroup city_list|dictsort:"country" by country as country_list %}

<ul>
{% for country in country_list %}
    <li><strong>{{ country.grouper }}</strong>
        <ul>
            {% for item in country.list %}
                <li>{{ item.city }}</li>
            {% endfor %}
        </ul>
    </li>
{% endfor %}
</ul>