All Questions
62 questions
0
votes
1
answer
73
views
where is the beginner_tutorials.srv file in the add_two_ints tutorial?
I am learning ros noetic on the page (https://wiki.ros.org/rospy_tutorials/Tutorials/WritingServiceClient)In the scripts/add_two_ints_server.py file within the beginner_tutorials package, there is a ...
- 11
0
votes
1
answer
829
views
rospy.init_node() stuck in loop
I had a problem with initializing a ROS node in python in a larger project. The following minimum reproducible example has the same issue:
...
- 1
1
vote
0
answers
162
views
Using .pyc files instead .py with roslaunch [closed]
I am working on a docker and using ROS 1 noetic as of now.
For certain reasons I do not want to distribute .py files as end user do not need to understand what is inside there. So I am using .pyc ...
- 133
0
votes
1
answer
163
views
Custom ROS Service Cannot be Imported
I have created a simple custom ROS service for ROS Noetic. My import line is:
from fishbot_ros.srv import chess_service, chess_serviceResponse
The file structure ...
0
votes
1
answer
9
views
unable to publish Path waypoints for pure pursuit
These are the initial line of my rospy code:
...
krushnal
0
votes
1
answer
11
views
how does one index array in rospy?
I need the size of a custom array msg type. (The type is geometry_msgs/PoseStamped[] PoseStampedArray.)
I need to iterate on the msg if it is not empty and I would very much like to get the last ...
gbohus
0
votes
1
answer
10
views
Importing a service in python defined by others
I am stuck in something that should be pretty easy... I have a service called "set_odometry", which I can use doing rosservice from the bash. This service is installed from apt-get so I don'...
Bernat Gaston
0
votes
1
answer
12
views
Smach get value from subscriber topic
I'm pretty new to ROS, and I'm working with SMACH. I have an Arduino UNO with 4 LEDs (green ,yellow, red and blue) and one button.
What I'm trying to achieve is a sort of traffic light simulator. My ...
rubbun
0
votes
1
answer
1
view
parse $(find ...) from python?
Hi everyone,
how can I make use of the ROS API to parse roslaunch macros like $(find <package>)?
Thanks
Originally posted by Hendrik Wiese on ROS Answers ...
Hendrik Wiese
0
votes
1
answer
5
views
Wrong argument type when writing quaternion orientation to pose message
Edit:
I tried to just simply copy the quaternion values and hardcode them as an orientation coordinates. Results are the same, so maybe problem comes from another part of my grasp msg?
I dumped the ...
fitter
0
votes
1
answer
6
views
Error on action_client as topic callback
I'm trying to implement a node that subscribes to a topic to get a list of geometry_msgs/Points and then send it to ...
bxl
0
votes
1
answer
3
views
PYTHON + ROS + V-REP
Hi
I have got a problem with publish data. I want to publish msg.linear.x and msg.linear.y to V-REP via ROS.
When I write in terminal
...
aefka
0
votes
1
answer
27
views
JointTrajectory Python interface
Hi, I am trying to make my own environment that will be used for reinforcement learning training, with the help of gym-gazebo. I want to train a floating gripper to pick up an object from ground. The ...
Fiddle
0
votes
1
answer
12
views
ROSSerializationException while publishing TFMessage
Hi everyone,
When I'm trying to publish tf2_msgs/TFMessage message, I got the following error:
...
Quang Le
0
votes
1
answer
147
views
How can I check if a service exists from Python?
This question has an answer for roscpp; what is the equivalent solution for Python?
EDIT: I do not want to wait for the service. I want to take one action if the service exists and a different action ...
BJP
0
votes
1
answer
8
views
Rospy isn't catching KeyboardInterrupt on the second iteration of the loop
I've written a publisher in Python to publish joint angles to a simple robot. The program only catches KeyboardInterrupt on the very first loop before I've ever published anything. However, as soon as ...
Mav16
0
votes
1
answer
13
views
Can I use the Python Ros bag API without making a workspace?
I'm using roscpp, but I'd like to make a transferrable python script for working with bag files. However, the docs only tell me how to do it through a catkin workspace. Is there a way to import the ...
cpagravel
0
votes
1
answer
132
views
Python OpenCV namedWindow and imshow freeze
Hi there,
I try to view a subscribed image via cv2.imshow() like the following:
...
UllusParvus
0
votes
1
answer
14
views
rostest fails when run using "catkin_make run_tests"
Hi all,
I have a node and some_test.test file like this:
...
ZdenekM
0
votes
1
answer
56
views
DC MOTOR + ENCODER + PYTHON
Hello, everyone.
I have the next equipment:
https://www.pololu.com/product/2598 ,
https://www.pololu.com/product/2208
and raspberry pi.
I want to control the dc motors via ROS and Python. Is it ...
Tvlad
0
votes
1
answer
4
views
Can't import rospy
Hello,
I have a ROS aplication in Python and Qt, and when I run it from the terminal all is ok, but I try to run with double click (the script with the permissions and Nautilus configuration ...
akb
0
votes
3
answers
277
views
point_cloud2.read_points and then?
I have a topic publishing a point cloud of type sensors_msgs.PointCloud2. I can subscribe to it and read it using ...
Mehdi.
0
votes
1
answer
165
views
How to exit a ROS node on keyboard interrupt?
How do you write a Python ROS node so that it exits in response to a KeyboardInterrupt exception?
I have a trivial node like:
...
Cerin
0
votes
1
answer
54
views
How to write to a text file in python in a ROS node?
I need to record a topic message called "message" only when a "message sent" button is pressed. I have made a separate node for GUI that has "message sent" button. I ...
Ros User
0
votes
1
answer
5
views
rospy.wait_for_message is unable to subscribe to a message continuosly
Hi everyone. I have a question about rospy.wait_for_message. In my program, I use rospy.wait_for_message(topic, data type) to wait for a message published by other node. The first program will wait ...
franciscs
0
votes
1
answer
47
views
Rviz markers with rospy
I am trying to visually represent a "robot" as a sphere marker from the visualization_msgs, but I am unable to publish my self.robotMarker. When I rosrun this script I am able to see the ...
jbourne
1
vote
2
answers
63
views
Passing arguments to callback in Python
Hi!
I have a problem passing arguments to a callback function when Subscribing a ROStopic. The code below is what I do have now. But I only received error messages when I tried to pass arguments to ...
steinaak
0
votes
1
answer
7
views
Python import: rosrun works well but roslaunch reports error
Hi, I'm writing some rospy nodes recently and some import errors ocur when I utilize roslaunch to start my node.
...
SilverBullet
0
votes
1
answer
11
views
Printing and searching python namespaces from rospy.get_param()
I am catkin-izing, updating, and making revisions to the nxt ROS packages. I have hit an issue that seems basic but I could use some help to get through it. Searches for accessing Python dictionaries ...
Derkabub
0
votes
1
answer
7
views
Crash when calling init_node while holding GIL
I'm getting a crash when trying to invoke rospy from within an embedded Python interpreter.
Ubuntu 14.04LTS
Python 2.7.6
rosdistro: jade
rosversion: 1.11.16
The following C/C++ file duplicates the ...
inflector
0
votes
1
answer
24
views
Use C++ camera_info_manager yamls with camera_info_manager_py, and vice versa?
I'd like to run camera_info_manager_py saveCalibrationFile in a python file and then load the same yaml in in C++, but it appears the yaml dump is saving like this:
...
- 3,397
0
votes
1
answer
3
views
One big subscriber vs. multiple small subscribers?
I'm using rospy.
I have several nodes that need camera image and point cloud.
each of them needs to get the rgb image and point cloud in real time.
I'm thinking about 2 structures
1.
Create one node ...
gliese581gg
1
vote
1
answer
270
views
Transform a pose to another frame with tf2 in Python
I have a pose stamped given in camera frame. Now I want to transform the pose to get its coordinates in the base_link frame.
Originally posted by fivef on ROS Answers with karma: 2756 on 2015-12-10
...
fivef
0
votes
2
answers
8
views
Get information about topic message at runtime
I am trying to build an interface that universally bridges ROS topics to another system.
I am importing the message type at runtime:
...
- 454
0
votes
1
answer
90
views
Python shutdown node
How i can shutdown a node in python?
In c++ is ros::shutdown() but in python i didn't find it.
Thanks
Originally posted by Porti77 on ROS Answers with karma: 183 on 2015-09-25
Post score: 2
Porti77
0
votes
1
answer
4
views
Adding __package__ to ROS Python scripts breaks import
I wanted to do a relative import from my Python ROS node.
So I added a __package__ = 'my_package' specification to the beginning of the file (right under the ...
- 599
0
votes
1
answer
21
views
Python rospy Script doesn't end running
Hey there,
i already talked to some guys in #python irc channel. My aim was to close a while loop with ctrl-c so i used a try - exception statement. The problem is that the while loop doesnt really ...
Holzroller
0
votes
1
answer
8
views
Error tf2_ros StaticTransformBroadcaster API in Python
Update:
In an attempt to get around losing the ability to pub latch transforms in the API in python I have tried doing the following which does not seem to work. Anyone have a way to do this? And in ...
rnunziata
0
votes
1
answer
36
views
Playback of rosbag file at the same rate that messages are stored in rospy
Hi,
I am trying to playback data that I have stored using rosbag in rospy. Is it possible to playback the rosbag file in rospy at the same rate that it is recorded? I know that I can do this from the ...
vkee
0
votes
2
answers
12
views
CMakeLists.txt: Install Python
What is the best way to install python libraries with a package?
This tutorial says how to do Python scripts, and I know you also need a setup.py, but I'm having trouble running ...
- 4,294
0
votes
1
answer
7
views
How to use variable's value (subscriber function) in another function
Hello all !
I want to pass the variable which is set to its value when called the callback function. and then want to use the value of the variable in another function.
...
jashanvir
0
votes
1
answer
33
views
Is it possible to launch multiple nodes from one python script?
I see that rospy.init_node() can only be called once per process in the official documentation on nodes.
I'm trying to write a script that allows for two-way ...
nckswt
0
votes
1
answer
113
views
Multiply two tf transforms converted to 4x4 matrices in python?
I want to do something along the lines of:
...
- 3,397
0
votes
1
answer
26
views
How to read a topic last value from a Python script?
Hello.
I'm working on a teleop program in Python. I want to change a joint position and add an offset read from the keyboard.
So I need to read a topic value to add the offset and send the command ...
Arn-O
0
votes
1
answer
5
views
import rospy when calling a python script from a c++ executable
I have a Robai Cyton gamma arm that I'm attempting to connect to with ROS by trying to call a Python script from a C++ program.
What I want to do is use C++ and OpenCV to get a video from an Xbox ...
nickd
0
votes
1
answer
8
views
Unable to install or run rospy
I've just installed the latest drcsim. From what I've read, a way to use python scripts is included in the ros package it comes with, rospy.
However, when I try to use rospy, the terminal does not ...
David Jeang
0
votes
1
answer
41
views
Using pypy with ROS for better performance?
How can I use pypy instead of the default python interpreter for a ROS node written in python ? I tried:
cd /path/to/node
pypy script/pioneer.py
But I'm getting an ...
victorp
0
votes
1
answer
39
views
ROSSerializationException while publishing PointCloud2 Message
Hello everyone,
when my node is publishing a PointCloud2 message I get the following error:
...
Josch
0
votes
1
answer
14
views
ROS hokuyo_node LaserScan Subscriber msg data class python
Hi I am trying to subscribe to a laser scan of the hokuyo_node. I am a bit new to ROS, here is my code so far. I have read the python subscriber tutorials but they don't tell how to subscribe to ...
Sentinal_Bias
0
votes
2
answers
3
views
Creating custom message and service for groovy, using them with Python
Hello,
I am discovering ROS groovy and I try to create a custom service. I followed the tutorial on creating a service with Python and did a Python node. But when I run my Python node, I get
'from ...
Manon