face module missing from python cv2 version 3.3.0
I have cv2 version 3.3.0 installed, as verified by printing cv2.__ version __
It is my understanding that version 3.3.0 should have the face module by default, as per this official documentation: http://docs.opencv.org/3.3.0/db/d7c/group__face.html
I installed opencv-python via pip.
Any ideas what is going wrong and how I can fix it?