def str_def(self):
        """
        :term:`string`: The exception as a string in a Python definition-style
        format, e.g. for parsing by scripts:

        .. code-block:: text

            classname={}; read_timeout={}; read_retries={}; message={};
        """
        return "classname={!r}; read_timeout={!r}; read_retries={!r}; " \
            "message={!r};". \
            format(self.__class__.__name__, self.read_timeout,
                   self.read_retries, self.args[0])