Error in installing pyqt5 on Ubuntu 18.04:
command “Python setup.py egg”_ info” failed with error code 1 in /tmp/pip-build-92ggdywh/PyQt5/

As a result, the version of PIP is too low. The default system version is pip9, so we need to update the PIP version
the update method is as follows:

python3 -m pip install --upgrade pip

Because most of the time, we install python, or apt install Python directly, resulting in the installation of python2.7. If you just want to use a version of python, such as python3, you can uninstall python2. It’s better to uninstall to avoid conflicts.