settings.py

COMPRESS_PRECOMPILERS = (
    ('text/coffeescript', 'coffee --compile --stdio'),
    ('text/x-scss', 'python manage.py template_filter {infile} | sass --scss --stdin {outfile}'),
)
COMPRESS_CSS_FILTERS = ['compressor.filters.cssmin.CSSMinFilter']

template_filter.py

from django.core.management.base import BaseCommand, CommandError
from django.contrib.staticfiles import finders

from django.template import Template, Context
from django.conf import settings

class Command(BaseCommand):
    args = '<input_file.scss>'

    def handle(self, *args, **options):
        if len(args) != 1:
            raise CommandError('Give filename as argument')
        filename = args[0]

        template = Template(open(finders.find(filename)).read())
        context = Context(settings.COMPRESS_TEMPLATE_FILTER_CONTEXT)
        data = template.render(context)

        self.stdout.write(data)