I've found a few questions here related to my issue, but I haven't found anything that has helped me resolve my issue. I'm using Python 2.7.5 and Django 1.8.dev20140627143448.

I have a view that's interacting with my database to delete objects, and it takes two arguments in addition to a request:

def delete_data_item(request, dataclass_id, dataitem_id):
    form = AddDataItemForm(request.POST)
    data_set = get_object_or_404(DataClass, pk=dataclass_id)
    context = {'data_set': data_set, 'form': form}
    data_item = get_object_or_404(DataItem, pk=dataitem_id)
    data_item.delete()
    data_set.save()
    return HttpResponseRedirect(reverse('detail', 
        args=(dataclass_id,)))

The URL in myapp.urls.py looks something like this:

url(r'^(?P<dataclass_id>[0-9]+)/(?P<dataitem_id>[0-9]+)/delete_data_item/$',
    views.delete_data_item, name='delete_data_item')

and the portion of my template relevant to the view is:

<a href="{% url 'delete_data_item' data_set.id data_item.id %}">DELETE</a>

Whenever I click on the DELETE link, django tells me that the request URL:

http://127.0.0.1:8000/myapp/5/%7B%%20url%20'delete_data_item'%20data_set.id%20data_item.id%20%%7D

doesn't match any of my URL patterns. What am I missing? The URL on which the DELETE links exist is myapp/(<dataclass_id>[0-9]+)/