Just to follow up on this matter. After struggling with PyDrive in pythonista for a while with resulting errors, I often to just go ahead and try the Google Drive API.
There is a super simple tutorial in codelabs:
Everything installs nicely and runs well.It even lets you complete the authentication in a separate browser if need be. I did the authentication on my raspberry pi and scped the secrets.jason and since then it works perfectly.
Just in case anyone wants to access and G suite files, you should know that pip in stash running in python3 nicely installs google-api-python-client and oauth2client in the site-packages-3 (which is all you need for Google Drive API).