1. Implement the publisher

Then create a new python file

Then copy the following code

#! /usr/bin/env python
"""
    需求: 实现基本的话题通信，一方发布数据，一方接收数据，
         实现的关键点:
         1.发送方
         2.接收方
         3.数据(此处为普通文本)

         PS: 二者需要设置相同的话题


    消息发布方:
        循环发布信息:HelloWorld 后缀数字编号

    实现流程:
        1.导包 
        2.初始化 ROS 节点:命名(唯一)
        3.实例化 发布者 对象
        4.组织被发布的数据，并编写逻辑发布数据


"""
#1.导包 
import rospy
from std_msgs.msg import String

if __name__ == "__main__":
    #2.初始化 ROS 节点:命名(唯一)
    rospy.init_node("talker_p")
    #3.实例化 发布者 对象
    pub = rospy.Publisher("chatter",String,queue_size=10)
    #4.组织被发布的数据，并编写逻辑发布数据
    msg = String()  #创建 msg 对象
    msg_front = "hello 你好"
    count = 0  #计数器 
    # 设置循环频率
    rate = rospy.Rate(1)
    while not rospy.is_shutdown():

        #拼接字符串
        msg.data = msg_front + str(count)

        pub.publish(msg)
        rate.sleep()
        rospy.loginfo("写出的数据:%s",msg.data)
        count += 1

Add executable permission

Open in integrated terminal, add executable permission

Then modify the configuration file

ctrl+s after modification

Then compile ctrl shift b

then start the terminal

You can see that there is an error

[rospack] Error package not found

This is because there is no source

You can see that there is an error

SyntaxError：Non ASCII

Solution

Remark

Every time you change, recompile

2. Implement the subscriber

create a new file

Enter the following code

#! /usr/bin/env python
"""
    需求: 实现基本的话题通信，一方发布数据，一方接收数据，
         实现的关键点:
         1.发送方
         2.接收方
         3.数据(此处为普通文本)


    消息订阅方:
        订阅话题并打印接收到的消息

    实现流程:
        1.导包 
        2.初始化 ROS 节点:命名(唯一)
        3.实例化 订阅者 对象
        4.处理订阅的消息(回调函数)
        5.设置循环调用回调函数



"""
#1.导包 
import rospy
from std_msgs.msg import String

def doMsg(msg):
    rospy.loginfo("I heard:%s",msg.data)

if __name__ == "__main__":
    #2.初始化 ROS 节点:命名(唯一)
    rospy.init_node("listener_p")
    #3.实例化 订阅者 对象
    sub = rospy.Subscriber("chatter",String,doMsg,queue_size=10)
    #4.处理订阅的消息(回调函数)
    #5.设置循环调用回调函数
    rospy.spin()

The reason for this error is because no permissions have been added

Just add permissions

Then

Note that in communication: the subscriber needs to register in the master before receiving data. At this time, it is easy to appear that the first few messages of the publisher have been sent, but the receiver has not received it.

Then look at the calculation graph