invalidate cached template fragments (tested with django 1.5 only)

gistfile1.py

from django.core.cache import cache
from django.utils.hashcompat import md5_constructor
from django.utils.http import urlquote

def invalidate_template_fragment(fragment_name, *variables):
    args = md5_constructor(u':'.join([urlquote(var) for var in variables]))
    cache_key = 'template.cache.{0}.{1}'.format(fragment_name, args.hexdigest())
    cache.delete(cache_key)