话题发布

#!/usr/bin/env python
import rospy
from geometry_msgs.msg import  Twist

def velocity_publisher():
	# ROS节点初始化
    #anonymous=True，表示后面定义相同的node名字时候，按照序号进行排列
    rospy.init_node('velocity_publisher',anonymous=True)
    # 创建一个Publisher，发布名为/turtle1/cmd_vel的topic，数据类型Twist
    turtle_vel_pub=rospy.Publisher('/turtle1/cmd_vel',Twist,queue_size=10)
    rate=rospy.Rate(10);
    while not rospy.is_shutdown():
        vel_msg=Twist()
        vel_msg.linear.x=0.5
        vel_msg.angular.z = 0.2
        turtle_vel_pub.publish(vel_msg)
        rospy.loginfo('%0.2f m/s, %0.2f rad/s',vel_msg.linear.x,vel_msg.angular.z)
        rate.sleep()
if __name__=='__main__':
    try:
        velocity_publisher()
    except rospy.ROSInterruptException:
        pass

话题订阅

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# 第一行很重要

import rospy
from turtlesim.msg import Pose

def lanelineInfoCallback(msg):
    rospy.loginfo("Subcribe laneline Info: angle:%d  delta_x:%d",
			 msg.x, msg.y)

def laneline_subscriber():
    # ROS节点初始化
    #anonymous=True，表示后面定义相同的node名字时候，按照序号进行排列
    rospy.init_node('pose_subscriber', anonymous=True)

	# 创建一个Subscriber，订阅名为/laneline_info的topic，注册回调函数lanelineInfoCallback
    rospy.Subscriber("/turtle1/pose", Pose, lanelineInfoCallback)

	# 循环等待回调函数
    rospy.spin()

if __name__ == '__main__':
    laneline_subscriber()