environment/lib/python2.7/site-packages/IPython/zmq/ipkernel.py
def _at_shutdown(self):
        """Actions taken at shutdown by the kernel, called by python's atexit.
        """
        # io.rprint("Kernel at_shutdown") # dbg
        if self._shutdown_message is not None:
            self.session.send(self.iopub_socket, self._shutdown_message, ident=self._topic('shutdown'))
            self.log.debug("%s", self._shutdown_message)
        [ s.flush(zmq.POLLOUT) for s in self.shell_streams ]
def _at_shutdown(self):
        """Actions taken at shutdown by the kernel, called by python's atexit.
        """
        # io.rprint("Kernel at_shutdown") # dbg
        if self._shutdown_message is not None:
            self.session.send(self.iopub_socket, self._shutdown_message, ident=self._topic('shutdown'))
            self.log.debug("%s", self._shutdown_message)
        [ s.flush(zmq.POLLOUT) for s in self.shell_streams ]
Actions taken at shutdown by the kernel, called by python's atexit.