Uh, no, I suggested that you use wix-fetch to access your REST Api you built in Python (so you pull the data inside Wix) and then use wix-fetch again to create a PDF with another REST Api.
The only thing I do not see is what advantage Wix brings here, since you could also have accessed the PDF REST Api from your Python app. Maybe you have built some HTML5-forms in Wix that you would like to use?