faces = faceCascade.detectMultiScale3(gray, scaleFactor=1.1, minNeighbors=5,
    minSize=(30, 30), flags=cv2.CASCADE_SCALE_IMAGE, outputRejectLevels=True)
rects = faces[0]
neighbours = faces[1]
weights = faces[2]
Getting the confidence level of detectMultiscale in OpenCV with Python?