Mohamed Mohamed - 2 years ago 204
Python Question

how to access dictionary element in django template?

I have this code in template, which I would like to printout number of votes that each choice got. votes is just dictionary while choices are model object.

{% for choice in choices %}
{{choice.choice}} - {{votes[]}} <br />
{% endfor %}

it raises an exception with this message "Could not parse the remainder"

Answer Source

To echo / extend upon Jeff's comment, what I think you should aim for is simply a property in your Choice class that calculates the number of votes associated with that object:

    class Choice(models.Model):
        text = models.CharField(max_length=200) 

        def calculateVotes(self):
            return Vote.objects.filter(choice = self).count()

        votes = property(calculateVotes)

And then in your template, you can do:

    {% for choice in choices %}
            {{choice.choice}} - {{choice.votes}} <br />
    {% endfor %}

The template tag, is IMHO a bit overkill for this solution, but it's not a terrible solution either. The goal of templates in Django is to insulate you from code in your templates and vice-versa.

I'd try the above method and see what SQL the ORM generates as I'm not sure off the top of my head if it will pre-cache the properties and just create a subselect for the property or if it will iteratively / on-demand run the query to calculate vote count. But if it generates atrocious queries, you could always populate the property in your view with data you've collected yourself.

Recommended from our users: Dynamic Network Monitoring from WhatsUp Gold from IPSwitch. Free Download