Django snippets

# settings.py
class InvalidVarException(object):
    def __mod__(self, missing):
        try:
            missing_str=unicode(missing)
        except:
            missing_str='Failed to create string representation'
        raise Exception('Unknown template variable %r %s' % (missing, missing_str))
    def __contains__(self, search):
        if search=='%s':
            return True
        return False

TEMPLATE_DEBUG=True
TEMPLATE_STRING_IF_INVALID = InvalidVarException()