gistfile1.mustache

{% load liczba_mnoga %}

<p>{% liczba_mnoga user_count "jedna osoba" "%(n)s osoby" "%(n)s osób" %}</p>

liczba_mnoga.py

from django import template
register = template.Library()

@register.simple_tag
def liczba_mnoga(n, form1, form2, form5):
    n = abs(n)
    if n == 1:
        return form1 % {'n': n}
    if n % 10 >= 2 \
            and n % 10 <= 4 \
            and (n % 100 < 10 or n % 100 >= 20):
        return form2 % {'n': n}
    return form5 % {'n': n}