Python opencv import error(undefined symbol) when i run the script , after i install ros kinetic

Question

When i import cv2 in a pyhton script i get the fallowing errore:

 File "script.py", line 4, in <module>
    import cv2
ImportError: /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5: undefined symbol: _Z10qAllocMoreii

I have ubuntu 16.04 and I install opencv with pip install opencv-python Way I get qt5 undefined symbol?

I install opencv after installing ros k.netic, and it seems that this thing causes the problem

Maby there is some interference between liberis/dependence names?

Answer 1

It looks like this problem is caused by ROS adding /opt/ros/k.netic/lib/python2.7/dist-packages to the python path. This actually happens when you activate ROS with the command source /opt/ros/k.netic/setup.bash. This line is often added at the end of your bashrc file, in /home/username/.bashrc.

A workaround is to remove this line from the bashrc file.

This was my solution:

import sys
import rospy
import rosbag
from cv_bridge import CvBridge, CvBridgeError

ros_path = '/opt/ros/kinetic/lib/python2.7/dist-packages'
if ros_path in sys.path:

    sys.path.remove(ros_path)

import cv2
sys.path.append('/usr/local/lib/python3.5/dist-packages')