Why won't my node exit

edit

Destroying the node won't exit rclpy.spin() loop. One way to implement this is by checking your node's self.running status in main loop and using rclpy.spin_once() -function. Here is a fully working example:

#!/usr/bin/env python3
import rclpy
from rclpy.node import Node


class MyNode(Node):
    def __init__(self, name):
        super().__init__(name)
        self.running = True
        self.timer = self.create_timer(0.1, self.action)

    def action(self):
        print("Callback")
        self.running = False
        self.destroy_timer(self.timer)


def main(args=None):
    rclpy.init(args=args)

    my_node = MyNode("my_node")
    while my_node.running and rclpy.ok():
        try:
            rclpy.spin_once(my_node)
        except KeyboardInterrupt:
            break

    my_node.destroy_node()
    print("Shutting down rclpy")
    rclpy.shutdown()


if __name__ == '__main__':
    main()