1:创建消息包
catkin_create_plg my_msgs roscpp rospy std_msgs message_generation message_runtime
这样就创建了一个名为my_msgs的包了
2:建scripts存放python代码
mkdir -r ~/catkin_ws/src/my_msgs/msg
touch ~/catkin_ws/src/my_msgs/msg/my_msg.msg
3:在my_msg.msg里放入你的消息类型
int64 person
int64 red
int64 green
int64 yellow
int64 sidewalk
int64 roadblock
int64 right
int64 left
int64 go
int64 stop