ROS-python实现简单的消息发布器和订阅器

因为着急做出东西来糊弄人，所以ROS的wiki看得马马虎虎一目十行，今天有些时间，仔细读了一下tutorials，对ROS有了一种恍然大明白的感觉，记录一下,方便以后操作，懒得再翻手册了：

1，首先要建一个工作空间，这个先不表了

2，其次要创建一个package，一个完整的程序包是这样的my_package/

CMakeLists.txt

package.xml

。这个程序包的路径注意下，在cd ~/dashgo_ws/src中创建。自不自定义你的程序包就看要求了，理解成描述文件就行。

3，编译程序包，首先source一下，source /opt/ros/groovy/setup.bash。在cd ~/catkin_ws/下执行catkin_make来编译一下。

4，用python写消息发布器

打开文件包：roscd beginner_tutorials

创建scripts

mkdirscripts cd scripts

编写talker.py

chmod +x talker.py

编写listener.py

chmod +x listener.py //赋予程序可执行权限

5，执行发布器和订阅器

打开发布器

首先

roscore

然后

cd /catkinws source ./devel/setup.bash

最后

rosrun beginner_tutorials talker.py

打开订阅器

cd /catkinws source ./devel/setup.bash

最后

rosrun beginner_tutorials listener.py

看一下代码吧

listener.py

1 #!/usr/bin/env python
2 import rospy
3 from std_msgs.msg import String
4 #回调格式 'listener_id heard hello world'
5 def callback(data):
6     rospy.loginfo(rospy.get_caller_id() + "I heard %s", data.data)
7
8 def listener():
9
10     # In ROS, nodes are uniquely named. If two nodes with the same
11     # node are launched, the previous one is kicked off. The
12     # anonymous=True flag means that rospy will choose a unique
13     # name for our 'listener' node so that multiple listeners can
14     # run simultaneously.
15     rospy.init_node('listener', anonymous=True)
16
17     rospy.Subscriber("chatter", String, callback)
18
19     # spin() simply keeps python from exiting until this node is stopped
20     rospy.spin()
21
22 if __name__ == '__main__':
23     listener()

没啥东西，就四个rospy库里面的函数（待补充）

rospy.loginfo

rospy.init_node

rospy.Subscriber

rospy.spin()

talker.py

1 #!/usr/bin/env python
2 # license removed for brevity
3 import rospy
4 from std_msgs.msg import String
5
6 def talker():
7     pub = rospy.Publisher('chatter', String, queue_size=10)
8     rospy.init_node('talker', anonymous=True)
9     rate = rospy.Rate(10) # 10hz
10     while not rospy.is_shutdown():
11         hello_str = "hello world %s" % rospy.get_time()
12         rospy.loginfo(hello_str)
13         pub.publish(hello_str)
14         rate.sleep()
15
16 if __name__ == '__main__':
17     try:
18         talker()
19     except rospy.ROSInterruptException:
20         pass

还是很easy，talker里面还加了个异常，真是严谨。总结完啦，下一篇谢谢ROspy吧。再次感慨一句，python五花八门的库真是新年吧多啊！！