from django import template

from symposion.reviews.models import ReviewAssignment


register = template.Library()


@register.assignment_tag(takes_context=True)
def review_assignments(context):
    request = context["request"]
    assignments = ReviewAssignment.objects.filter(user=request.user)
    return assignments

from django import template

from symposion.reviews.models import ReviewAssignment


register = template.Library()


@register.simple_tag(takes_context=True)
def review_assignments(context):
    request = context["request"]
    assignments = ReviewAssignment.objects.filter(user=request.user)
    return assignments

Use simple_tag instead of assignment_tag.
Use simple_tag instead of assignment_tag.

https://docs.djangoproject.com/en/2.2/releases/1.9/#assignment-tag
