qtpy.PythonQtError: No Qt bindings could be found

I faced a similar problem, however, for me, the solution was an easy one. Please go through the following points.

1. Keep a native python installed on your machine.
2. Run "pip install pyqt5-tools" from cmd.
3. You should have a message on screen post-installation - "Successfully installed click-7.0 pyqt5-5.13.0 pyqt5-tools-5.13.0.1.5 python-dotenv-0.10.3" :

Installation snap for Reference

Hope this will work for you :)

I had the same problem "qtpy.PythonQtError: No Qt bindings could be found" after an update to spyder 4.0.1

After trying $pip3 install -U pyqt5 --user I got the error message:

_'ERROR: spyder 4.0.1 has requirement pyqt5<5.13; python_version >= "3", but you'll have pyqt5 5.14.1 which is incompatible.'_

So I updated with a compatible version:

pip3 install pyqt5==5.12 --user

And now spyder is working.