Use python3 with ROS

[rickstaa]

As the GQCNN package I was using recommended python3 I tried to get ROS to work with Python3. A guide on how to use ROS with python3 can be found here. A list of all the ROS distributions with the python version support can be found here. Below I summarised my findings so others can use it as a guide when they want to use ROS with melodic.

ROS kinetic with python 3

Since at the start of my internship franka_ros wasn't released for melodic I had to use kinetic. However, since ROS kinetic does not fully support python3 getting the GQCNN to work under ubuntu 16.04 ROS Kinetic is not easy. I kept running into problem after problem. In the end, I decided to contribute python 2/python 3 compatibility fixed to the python 3 repositories and use python 2.7 instead. If other people really need to work with python 3 and ROS kinetic, please refer to this ros issue.

ROS melodic with python 3

As stated in the distribution list ROS ROS Python packages starting with Melodic Morenia are highly encouraged to support both Python 2.7 and Python 3.5 or later. As a result, full ROS Melodic python 3 support is on its way. The core packages in ROS melodic are currently being ported from python 2 to python 3. If you, however, have to use a package that is not yet ported to python 3 you have to build this package from source. As explained by @gvdhoorn the procedure of doing this can be found here

Additional Resources

• How can I install ROS melodic with python3
• ROS melodic python 3 installation tutorial
• Write python 2 python 3 compatible code
• Py2Py3 cheatcheat

[rickstaa]

I switched to python 2.7. The answer on how to implement it in python 3 can be found on this ros issue.