cache_bust.py

from django import template
from django.conf import settings
from os.path import join, getmtime

register = template.Library()

@register.simple_tag
def static_asset(filename):
    """
    {% load static_asset %}
    <link rel="stylesheet" href="{% static_asset "css/main.css" %}" type="text/css">

    Renders a link like:
    <link rel="stylesheet" href="/media/css/main.css?v=12921928" type="text/css">
    """
    try:
        filemtime = str(getmtime(join(settings.STATIC_ROOT, filename)))[:8]
    except:
        filemtime = 0

    return '%s%s?v=%s' % (settings.STATIC_URL, filename, filemtime)