If you have a problem with ros_comm
built with python3
on Ubuntu 18.04 like
$ rostopic list
Traceback (most recent call last):
File "/home/user/Workspace/catkin_ws/devel/bin/rostopic", line 15, in <module>
exec(compile(fh.read(), python_script, 'exec'), context)
File "/home/user/Workspace/catkin_ws/src/ros_comm/tools/rostopic/scripts/rostopic", line 35, in <module>
rostopic.rostopicmain()
File "<string>", line 2118, in rostopicmain
File "/home/user/Workspace/catkin_ws/devel/lib/python3/dist-packages/rosbag/__init__.py", line 34, in <module>
exec(__fh.read())
File "<string>", line 33, in <module>
File "/home/user/Workspace/catkin_ws/src/ros_comm/tools/rosbag/src/rosbag/bag.py", line 53, in <module>
from Cryptodome.Cipher import AES
ModuleNotFoundError: No module named 'Cryptodome'
Solution
pip3 install pycryptodome pycryptodomex python-gnupg