ERROR: Could not build wheels for opencv-python which use PEP 517 and cannot be installed directly
I had the same problem and i did this,
pip install --upgrade pip setuptools wheel
then install opencv again,
pip install opencv-python
this worked for me
Yes .. Finally found a work around. Follow this https://github.com/mdegans/nano_build_opencv and build from source and finally gets installed.
PS: It may take a bit long for building, for me it took 10 Hrs :P.