You can upload the files to icloud and then transfer them to google drive. See this article here for an example on how to do this.
Edit: This will only work if you have a mac hooked up to icloud. To do this straight from your phone you can:
Save the file to icloud straight from pythonista
Make sure you have the google drive app, and that you are logged in
Go to icloud and click the share button (box with the arrow pointing up)
Click the "drive" icon, and your file will be stored on your drive
I hope this helps, let me know if you have any further questions (@coreos @AndyCWB)