Multithreading vision OCR on Mac with pyobjc

1. I'm trying to OCR 1 million pdfs 2. I found apple's vision api's ocr is the most cost effective and high quality way to scan the files 3. I have some code I found on github I am using to run this https://gist.githubusercontent.com/RhetTbull/1c34fc07c95733642cffcd1ac587fc4c/raw/0f8c86b68a23337fd5c072c10911e424a35fadc8/vision.py

4. I don't know much objective-c to be honest, and I don't know where to get started with multithreading with pyobjc. the regular python modules don't really work. can you even multithread the ocr process so multiple pdfs are processed at the same time with vision api?