Sum in html template using template tag

Question

I am trying to sum in HTML,but template tag return 0 ,

View.py

def gen_Report(request):

### query returns below output 
list=[{\'total\': 1744, \'us         


        

Answer 1

I suspect that your list is an iterator. So the first time it iterates over and the second time it iterate over nothing. So you should do something like this

for d in list_total:
   d.set('list_sum', list(d.get('list_sum')))

before calling your template

Answer 2

Your template tag looks wrong. You have role_total as the parameter and then iterate through list_total (seemingly undefined) and from each dictionary in the list try getting the key list_sum which is also seemingly undefined.

from django.template import Library
register = Library()
@register.filter
def running_total(your_dict_list):
   return sum(d['total'] for d in your_dict_list)

and calling it from the template at as <td>{{ list|running_total}}</td>