ROS Resources: Documentation | Support | Discussion Forum | Index | Service Status | ros @ Robotics Stack Exchange
Ask Your Question
0

Variable namespaces in classes (Python3)

asked 2022-04-11 08:16:06 -0600

WarTurtle gravatar image

I am having difficulties using variable namespaces with python3 classes

Here's a snippet of code that I would think would work, but doesn't.

In the BasicNavigator class:

    self.namespace = ''

    self.localization_pose_sub = self.create_subscription(PoseWithCovarianceStamped,
                                                          self.namespace + '/amcl_pose',
                                                          self._amclPoseCallback,
                                                          amcl_pose_qos)

In main:

navigator = BasicNavigator()

navigator.namespace = "robot1"

This does not work, it does not recognize the "robot1" in the class.

Instead, if I remove the self.namespace and just write the topic name as such: 'robot1/amcl_pose' it works, but I need to be able to have a variable amount of robots...

What am I doing wrong?

edit retag flag offensive close merge delete

Comments

Very likely the subscription is getting created beforeself.namespace is being set to robot1. What if you made the constructor of BasicNavigator take in a namespace, so that you can do something like self.namespace = namespace?

abhishek47 gravatar image abhishek47  ( 2022-04-11 11:31:38 -0600 )edit

As the previous comment said, you need to rearrange when you're setting the namespace and when the subscription is created.

aprotyas gravatar image aprotyas  ( 2022-04-11 14:50:09 -0600 )edit
add a comment

1 Answer

Sort by ยป oldest newest most voted
1

answered 2022-04-12 07:37:06 -0600

WarTurtle gravatar image

Thanks, abhishek47 and aprotyas for your comments. It worked by creating a method with the namespace argument.

In BasicNavigor class:

def createSubscriptions(self, namespace):
    self.localization_pose_sub = self.create_subscription(PoseWithCovarianceStamped,
                                                          namespace + 'amcl_pose',
                                                          self._amclPoseCallback,
                                                          amcl_pose_qos)

And then I call this in main:

navigator = BasicNavigator()

namespace = "robot1"
navigator.createSubscriptions(namespace)

Not sure if this is exactly what you wanted me to try, but it works, so I'm happy :)

edit flag offensive delete link more

Comments

Something along these lines, yes. Good to know that it worked!

aprotyas gravatar image aprotyas  ( 2022-04-13 00:18:37 -0600 )edit
add a comment

Question Tools

2 followers

subscribe to rss feed

Stats

Asked: 2022-04-11 08:16:06 -0600

Seen: 225 times

Last updated: Apr 12 '22

Related questions

Do I need to know any specific computer language or framework to use ROS?

Is anybody in ROS community using PySide?

Any good examples of using dynamic_reconfigure for a python node?

is there a python equivalent of fromROSMsg/toROSMsg (pcl stack)

How to contributing python versions of tutorials? e.g. Tutorials for arm_navigation

How to recieve an array over Publisher and Subscriber? (Python)

Python bullet bindings

Error assigning a python quaternion

Using python for automatically writing data in bag to csv file

How to use Python setuptools to build a Python extension

ROS Answers is licensed under Creative Commons Attribution 3.0 Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.
about | faq | help | privacy policy | terms of service
Powered by Askbot version 0.10.2