python实现ROS的TOPIC通信_ros topic搜索python

ROS 版本是

PARAMETERS
 * /rosdistro: melodic
 * /rosversion: 1.14.12

utuntu 系统版本 18.04

1.工作空间是存放工程开发的相关文件的文件夹

src：代码空间

build：编译空间

devel：开发空间

install：安装空间

2.创作工作空间指令

$mkdir -p ~/catkin_ws/src
$cd ~/catkin_ws/src
$catkin_init_workspace

编译工作空间(注意编译工作空间一定要在工作空间的根目录下)

$ cd ~/catkin_ws/
$ catkin_make

设置环境变量

$ source devel/setup.bash

检查环境变量

$ echo $ROS_PACKAGE_PATH

3 创建功能包

创建功能包指令

$ cd ~/catkin_ws/src
$ catkin_create_pkg test_pkg std_msgs rospy roscpp

编译功能包

$ cd ~/catkin_ws
$ catkin_make
$ source ~/catkin_ws/devel/setup.bash

4. 创建Topic的订阅发布方法

创建源码文件夹

$ mkdir ~/catkin_ws/src/test_pkg/scripts

创建publisher的python文件

$ cd ~/catkin_ws/src/test_pkg/scripts
$ vim talker.py

talker.py内容

#!/usr/bin/env python
 
import rospy
from std_msgs.msg import String
 
def talker():
    pub = rospy.Publisher('chatter', String, queue_size=10)
    rospy.init_node('talker', anonymous=True)
    rate = rospy.Rate(10) # 10hz
    while not rospy.is_shutdown():
        hello_str = "hello world %s" % rospy.get_time()
        rospy.loginfo(hello_str)
        pub.publish(hello_str)
        rate.sleep()
 
if __name__ == '__main__':
    try:
        talker()
    except rospy.ROSInterruptException:
        pass

 创建订阅的python文件

$ cd ~/catkin_ws/src/test_pkg/scripts
$ vim listener.py

listener.py的内容

#!/usr/bin/env python
 
import rospy
from std_msgs.msg import String
 
def callback(data):
    rospy.loginfo(rospy.get_caller_id() + 'I heard %s', data.data)
 
def listener():
 
    # In ROS, nodes are uniquely named. If two nodes with the same
    # name are launched, the previous one is kicked off. The
    # anonymous=True flag means that rospy will choose a unique
    # name for our 'listener' node so that multiple listeners can
    # run simultaneously.
    rospy.init_node('listener', anonymous=True)
 
    rospy.Subscriber('chatter', String, callback)
 
    # spin() simply keeps python from exiting until this node is stopped
    rospy.spin()
 
if __name__ == '__main__':
    listener()

python不需要编译CMakeList.txt文件

直接运行roscore，以及listener.py,talker.py

运行ros程序

$ roscore

打开新的Terminal，运行 talker

$ cd ~/catkin_ws/src/test_pkg/scripts
$ python talker.py

打开新的Terminal，运行 listener

$ cd ~/catkin_ws/src/test_pkg/scripts
$ python listener.py

运行结果