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Hey all,
I am using ROS Noetic and I have a a python 3 script that is being launched with a launch file. To further automatize my project, I wanted to know if it's possible to include input on the launch file to be used within the python script? And if so, How do I do it?
Thank you
The best would be to create parameters in your python script. Examples here (Make them private with ~)
For example in my node I have :
self.target_frame = rospy.get_param("~target_frame", "map")
And I can start it like this in in my launchfile :
<node pkg="robot_platform" type="test.py" name="test" output="screen">
<param name="target_frame" value="test" />
</node>
This method is very good because it allows you to use the parameter server to set your parameters also and load them from a yaml file for example.
You can read more about the parameter server here
Hey! I tried your approach but on the terminal I keep getting a KeyError. MY launch file is below:
<?xml version="1.0"?>
<launch>
<node pkg="gspn_framework_package" ns="robot_1" type="gspn_execution_node.py" name="executor_1">
<param name="user_robot_id" value="1" />
<param name="user_current_place" value="p1" />
</node>
<node pkg="gspn_framework_package" ns="robot_2" type="gspn_execution_node.py" name="executor_2">
<param name="user_robot_id" value="2" />
<param name="user_current_place" value="p3" />
</node>
</launch>
And on my Python I have:
namespace = rospy.get_namespace()
user_robot_id = rospy.get_param(namespace + "user_robot_id")
user_current_place = rospy.get_param(namespace + "user_current_place")
What am I doing wrong? I also tried without the namespace but I had the same error.
I didnt use rospy.get_namespace.
If you put ~ at the beginning of your param name to set it private you shouldn't need it,
Like so :
user_robot_id = rospy.get_param("~user_robot_id")
user_current_place = rospy.get_param("~user_current_place")
Does it solve your problem ?
Sadly, I still get the KeyError. I did exactly as you told me: without using the namespace and using the "~". Maybe there's something wrong in my launch file.
Okay it worked! I was doing rospy.init_node() afterwards. Thank you :)
Asked: 2020-06-03 03:57:20 -0500
Seen: 1,058 times
Last updated: Jun 03 '20
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