Question

I am processing a queryset in a view to get a summary of data and need to be able to iterate over the resultant dataset in my template. I did this OK with a key and single value by building a dictionary and then using .items to work over key value pairs using:

{% for id,total in list_summary.items %}
    <tr class="{% cycle 'row1' 'row2' %}" >
        <td>{{id}}</td>
        <td>{{total}}</td>
    </tr>
{% endfor %}

The problem I have is that I need more than just a key and value. I need multiple values. I tried building a dictionary using a dictionary as the value but in the template I can’t get to the values in the dictionary.

What is the appropriate datastructure to build to make this work? I thought of a temporary model or making a custom template tag to access the sub dictionary values but I think there must be a better way to process queryset data prior to feeding it to a view.

My view code is here:

lists=lists.objects.filter(user_id=user_id)
list_summary={}
# make a dictionary that we wil iterate over in template. The dictionary has the total spend for each deal 
for list in lists:
    id       = list.id
    name     = list.deal_name
    price    = list.normal_price
    quantity = list.quantity
    total    = price * quantity
    try:
        list_item=list_summary[id]
        old_total=list_item['total']
        list_summary[id]={'name':name, 'total':old_total + total}
    except:
        list_summary[id]={'name':name, 'total':total}
context = {
           'list_summary':list_summary,
        }
return render_to_response("lists.html", context)

Any help would be much appreciated!

Many thanks in advance

Rich

Answer 1

I tried building a dictionary using a dictionary as the value but in
the template I can’t get to the values in the dictionary.

Why not? The values are also key/value pairs..

{% for list_id, dict in list_summary.items %}
    list_id: {{ list_id }}
    {% for k, v in dict.items %}
        key: {{ k }} <!-- name, total -->
        value: {{ v }} 
    {% endfor }
{% endfor %}


{% for list_id, value in list_summary.items %}
    list_id: {{ list_id }}
    Name: {{ value.name }}
    Value: {{ value.value }
{% endfor %}