How to add, multiply number variables in a Django template?

Question

The JS snippet I created relies on the forloop.counter variable being available within a {% for key, value in data.items %}..{% endfor %} tag.

Is there

Answer 1

After Mathieu Marques tips, here's what I did using custom filter.

The template is rendering 5 record per page after using pagination snippet. The per page presentation reset the forloop.counter. To create a continous counter per page..

from django import template
register = template.Library()

@register.filter(name='cei')
def compute_exact_id(value, rb_page_no):    
    new_id = value+(5*(rb_page_no-1))    ## here's the mathematical operation
    return new_id

where rb_page_no is the current page number and placing {% load extra_filter %} on top my template where extra_filter is the file name where I place the compute_exact_id.