this will help The easiest way to install PyQt is to just use the installer (Link in your answer, step #5). If you install python 3.3, the installer will add all of the PyQt5 extras to that python installation automatically. You won't need to do any compiling (none of: nmake, nmake install, python configure). All of the build options are available for if you need a custom install (for instance, using a different version of python, where there isn't an installer provided by riverbank computing).
wish help you to fix your issue I`m trying to install python3-pyqt5, but still getting the same error. I tried reinstalling ubuntu, updating and upgrading my apt-get and still no clue whats wrong. , I found that I just needed to type:
sudo add-apt-repository universe
sudo apt-get update
Impossible to install python3 PyQt5 module with pip3 in Gitlab CI