I believe the file gets created in the sites folder using that code. Frappe does have some methods to get paths for different things like the site base path and the public files folder path. I haven’t tested it out much but you can see all the methods here. I assume get_files_path would do the job. So far I’ve only used get_request_site_address like so. Had to use it to embed the letterhead img I was testing with. Could only get it to work with absolute paths for some reason (might help when you get to that part).
from frappe.utils import get_request_site_address
path = frappe.utils.get_request_site_address()