报错：error: (-2:Unspecified error) File can't be opened for writing! in function 'cv::face::FaceRecognizer::write'
说明函数本身无法自己建立文件夹，所以要自己创建一个文件夹
报错：报错信息:AttributeError: module ‘cv2‘ has no attribute ‘face‘
pip uninstall opencv-python
pip uninstall opencv-contrib-python
pip install opencv-python==4.5.4.58
pip install opencv-contrib-python==4.5.4.58