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 | 1 | initial version |
>>> print('\n'.join(sys.path)) /usr/local/lib/jython2.7.0/Lib __classpath__ __pyclasspath__/ /usr/local/lib/jython2.7.0/Lib/site-packages /usr/lib/python2.7/dist-packages /usr/local/lib/python2.7/dist-packages >>> import rospy Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: No module named rospy
Seeing as ROS is installed in /opt/ros/$ROSDISTRO, with the Python packages all in /opt/ros/$ROSDISTRO/lib/python2.7/dist-packages, it seems without that path on the sys.path it would be expected Jython can't import rospy.
| | 2 | No.2 Revision |
>>> print('\n'.join(sys.path)) /usr/local/lib/jython2.7.0/Lib __classpath__ __pyclasspath__/ /usr/local/lib/jython2.7.0/Lib/site-packages /usr/lib/python2.7/dist-packages /usr/local/lib/python2.7/dist-packages >>> import rospy Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: No module named rospy
Seeing as ROS is installed in /opt/ros/$ROSDISTRO, with the Python packages all in /opt/ros/$ROSDISTRO/lib/python2.7/dist-packages, (at least for ROS versions which use Python 2), it seems without that path on the sys.path it would be expected Jython can't import rospy.
| | 3 | No.3 Revision |
>>> print('\n'.join(sys.path)) /usr/local/lib/jython2.7.0/Lib __classpath__ __pyclasspath__/ /usr/local/lib/jython2.7.0/Lib/site-packages /usr/lib/python2.7/dist-packages /usr/local/lib/python2.7/dist-packages >>> import rospy Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: No module named rospy
Seeing as ROS is installed in /opt/ros/$ROSDISTRO, with the Python packages all in /opt/ros/$ROSDISTRO/lib/python2.7/dist-packages (at least for ROS versions which use Python 2), it seems without that path on the sys.path it would be expected Jython can't import rospy.
Edit:
I'm not sure what you're getting at. Should I add to Jython
/opt/ros/$ROSDISTRO?
No. If you had not built ROS from source, you would have had to add /opt/ros/$ROSDISTRO/lib/python2.7/dist-packages, as that's where all the Python packages live.
By the way I build it from source because Ubuntu 18.04 does not support ROS Kinetic so isntead of
/opt/ros/$ROSDISTROI should have to use~/ros_catkin_ws.This would be the right solution. But which is the correct one I have to use?
>>> sys.path.append('/home/openhabvm/ros_catkin_ws/build_isolated') >>> sys.path.append('/home/openhabvm/ros_catkin_ws/devel_isolated') >>> sys.path.append('/home/openhabvm/ros_catkin_ws/install_isolated') >>> import rospy >>>Build, Devel or Install?
If you have an install space, you must use it. If you don't have an install space (so only a devel), then use the devel space.
In your case that's install_isolated, as you probably used catkin_make_isolated to build your workspace.
I am amazed. It didn't work if I left out individual things, and somehow I also have to consider an appropriate order. One also needs:
>>> sys.path.append('/home/openhabvm/ros_catkin_ws') >>> sys.path.append('/home/openhabvm/ros_catkin_ws/src')
I would not expect this to be needed, as it isn't when using a regular Python interpreter. But perhaps Jython is different.
and:
>>> sys.path.append('/usr/local/lib/python2.7/dist-packages')
It could be this is needed if Jython is not using the default dist-packages (ie: the one managed by apt) and you've installed certain ROS Python dependencies manually in /usr/local.
The build-ROS-from-sources instructions do not do that though, so that would have been something you've done yourself.
Well it is not the whole ROS integration. I can not import std_msgs as example. I got this error:
>>> from std_msgs.msg import String Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: cannot import name StringOf course, I also have a suspicion where this comes from. But I won't be the only one who first comes up with one solution and then looks for the next. It may be possible to link it later, should my project succeed.
As I don't know exactly what you've done, I can't comment on this. std_msgs is a pretty low-level dependency though, so if you can import rospy, I would expect std_msgs to also be present.
| | 4 | No.4 Revision |
>>> print('\n'.join(sys.path)) /usr/local/lib/jython2.7.0/Lib __classpath__ __pyclasspath__/ /usr/local/lib/jython2.7.0/Lib/site-packages /usr/lib/python2.7/dist-packages /usr/local/lib/python2.7/dist-packages >>> import rospy Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: No module named rospy
Seeing as ROS is installed in /opt/ros/$ROSDISTRO, with the Python packages all in /opt/ros/$ROSDISTRO/lib/python2.7/dist-packages (at least for ROS versions which use Python 2), it seems without that path on the sys.path it would be expected Jython can't import rospy.
Edit:
I'm not sure what you're getting at. Should I add to Jython
/opt/ros/$ROSDISTRO?
No. If you had not built ROS from source, you would have had to add /opt/ros/$ROSDISTRO/lib/python2.7/dist-packages, as that's where all the Python packages live.
By the way I build it from source because Ubuntu 18.04 does not support ROS Kinetic so isntead of
/opt/ros/$ROSDISTROI should have to use~/ros_catkin_ws.This would be the right solution. But which is the correct one I have to use?
>>> sys.path.append('/home/openhabvm/ros_catkin_ws/build_isolated') >>> sys.path.append('/home/openhabvm/ros_catkin_ws/devel_isolated') >>> sys.path.append('/home/openhabvm/ros_catkin_ws/install_isolated') >>> import rospy >>>Build, Devel or Install?
If you have an install space, you must use it. If you don't have an install space (so only a devel), then use the devel space.
In your case that's install_isolated, as you probably used catkin_make_isolated to build your workspace.
I am amazed. It didn't work if I left out individual things, and somehow I also have to consider an appropriate order. One also needs:
>>> sys.path.append('/home/openhabvm/ros_catkin_ws') >>> sys.path.append('/home/openhabvm/ros_catkin_ws/src')
I would not expect this to be needed, as it isn't when using a regular Python interpreter. But perhaps Jython is different.
and:
>>> sys.path.append('/usr/local/lib/python2.7/dist-packages')
It could be this is needed if Jython is not using the default dist-packages (ie: the one managed by apt) and you've installed certain ROS Python dependencies manually in /usr/local.
The build-ROS-from-sources instructions do not do that though, so that would have been something you've done yourself.
Well it is not the whole ROS integration. I can not import std_msgs as example. I got this error:
>>> from std_msgs.msg import String Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: cannot import name StringOf course, I also have a suspicion where this comes from. But I won't be the only one who first comes up with one solution and then looks for the next. It may be possible to link it later, should my project succeed.
As I don't know exactly what you've done, I can't comment on this. std_msgs is a pretty low-level dependency though, so if you can import rospy, I would expect std_msgs to also be present.
Edit 2: I'm wondering whether it wouldn't have been simpler to use rospypi/simple to setup a self-contained, minimal virtualenv with just rospy and some extra packages, instead of building ROS Kinetic from source on Ubuntu Bionic.
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