rospy ROS1 Connection Header Secret !

launch.launch

<?xml version="1.0"?>
<launch>
    <node pkg="test_pkg" type="quick_publisher.py" name="my_talker_1" output="screen" />
    <node pkg="test_pkg" type="quick_publisher.py" name="my_talker_2" output="screen" />
    <node pkg="test_pkg" type="quick_publisher.py" name="my_talker_3" output="screen" />
    <node pkg="test_pkg" type="quick_publisher.py" name="my_talker_4" output="screen" />
</launch>

quick_publisher.py

#!/usr/bin/env python3

import random
import rospy
from std_msgs.msg import String
class Talker(object):
    def __init__(self):
        self.publisher = rospy.Publisher("/chatter", String, queue_size=1)
        self.rand = random.randint(1,4)
        self.rate = rospy.Rate(self.rand)
        self.node_name = rospy.get_name()
        rospy.Timer(self.rate.sleep_dur, self.timer_cb)

    def timer_cb(self, _):
        msg = String()
        msg.data = "Hello World from : {}".format(self.node_name)
        rospy.loginfo("[%s][%d] Publishing: %s",self.node_name, self.rand, msg.data)
        self.publisher.publish(msg)

if __name__ == "__main__":
    rospy.init_node("talker")
    TALKER = Talker()
    rospy.spin()

quick_subscriber.py

#!/usr/bin/env python3

import rospy
from std_msgs.msg import String

class Listener(object):
    def __init__(self):
        self.subscriber = rospy.Subscriber("/chatter", String, self.callback)

    def callback(self, msg):
        rospy.loginfo("From : [%s] I heard: %s", msg._connection_header["callerid"], msg.data)

if __name__ == "__main__":
    rospy.init_node("listener")
    LISTENER = Listener()
    rospy.spin()