If PyQt5 and sip.cpython-36m-x86_64-linux-gnu.so are not in /usr/lib/python3/dist-packages/ they are not installed with apt-get and that's the possible reason if they are not the 18.04 versions.
If PyQt5 and sip.cpython- 36m-x86_ 64-linux- gnu.so are not in /usr/lib/ python3/ dist-packages/
they are not installed with apt-get and that's the possible reason if they are not the 18.04 versions.