def _get_path(self, parent, key):
        """
        Returns the qualified directory path for a directory entry.
        """
        if parent == "/":
            return parent + key
        elif parent.startswith("/"):
            return parent + "/" + key
        else:
            raise BadRequest(parent % "Illegal parent: %s")
dataset/ETHPy150Open ooici/pyon/pyon/ion/directory.py/Directory._get_path/swapped operands of `%`