PyQt5 not finding installed Qt5 library

Question

On Ubuntu 16.0.4, I am trying to run this PyQt5 script, and I have the distributed packages for Qt5 (via apt) and PyQt5 (via pip3) installed.

Error:

sudo ./video_qt.py

Traceback (most recent call last): File "./video_qt.py", line 8, in from PyQt5 import QtWidgets, QtCore ImportError: /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5: version `Qt_5' not >found (required by /usr/local/lib/python3.5/dist-packages/PyQt5/QtWidgets.so)

But it is there:

ls /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5

/usr/lib/x86_64-linux-gnu/libQt5Gui.so.5

What could be going on here?

Answer 1

I do not have ubuntu to check on.

I would guess that the PyQt in PyPI is not compatible with the installed Qt .so files.

Try pip3 uninstall PyQt and install PyQt from apt should get you binaries that work together.

If its not in apt, ask unbuntu to package it or build PyQt from source. Which not that hard to do.

Answer 2

I received a similar error message except mine was specifically looking for `Qt_5.12', but it looks like more or less the same problem (version mismatch). I was trying to run my script as:

python3 main.py

I tried uninstalling and reinstalling Qt5 with pip and apt-get, none of that helped. What fixed the problem for me was calling my script with a direct path to python3:

/usr/bin/python3 main.py

Hope this saves someone a headache!