def _validate_backend(self):
        """ ensure backend string representation is correct """
        try:
            self.backend_class
        # if we get an import error the specified path is wrong
        except (ImportError, AttributeError) as e:
            raise ValidationError(_('No valid backend found, got the following python exception: "%s"') % e)
def _validate_backend ( self ) : try : self . backend_class except ( ImportError , AttributeError ) as e : raise ValidationError ( _ ( 'No valid backend found, got the following python exception: "%s"' ) % e )
ensure backend string representation is correct