转载：module 'cv2.cv2' has no attribute 'xfeatures2d'（问题已解决，亲测有效！）

https://blog.csdn.net/weixin_43167047/article/details/82841750

C:\projects\opencv-python\opencv_contrib\modules\xfeatures2d\src\sift.cpp:1207: error: (-213:The function/feature is not implemented) This algorithm is patented and is excluded in this configuration; Set OPENCV_ENABLE_NONFREE CMake option and rebuild the library in function ‘cv::xfeatures2d::SIFT::create’
貌似是该算法被申请了专利还是咋的，将opencv版本退到3.4.2即可解决，卸载之前的包，然后
pip install opencv-python3.4.2.16
pip install opencv-contrib-python3.4.2.16
亲测有效！