发布方实现：

#! /usr/bin/env python
import rospy
from std_msgs.msg import String

if __name___ == "__main__":
  rospy.init_node("pub")
  pub = rospy.Publisher("chatter",String,queue_size = 10)
  msg = String()
  msg_front = "hello"
  rate = rospy.Rate(1)
  count = 0
  while not rospy.is_shutdown():
    msg = msg_front + str(count)
    pub.publish(msg)
    rate.sleep()
    count += 1
    rospy.loginfo("发送的内容为：%s", msg.data) 

订阅方式实现：

#! /usr/bin/env python
import rospy
from std_msgs.data import String
def doMSG(msg):
  rospy.loginfo("接收到的内容为:%s",msg.data)
 if __name__ == "__main__":
  rospy.init_node("sub")
  sub = rospy.Subscriber("chatter",String,doMSG,queue_size = 10)
  rospy.spin()