### Expected behaviour I use `python3.6.5 amd64` and `opencv-contrib-python-3.4.3.18`, seems that "SIFT" module is not in this lib... It works fine in opencv-contrib-python-3.4.2.17, like below:  ### Actual behaviour  ### Steps to reproduce - example code: ```python import cv2 sift = cv2.xfeatures2d.SIFT_create(edgeThreshold=10) ``` - Win7 64bit Professional - python amd64 - `opencv-contrib-python-3.4.3.18`