For stackoverflow http://stackoverflow.com/questions/16011049/google-drive-api-and-service-account small app

gistfile1.py

# -*- coding: utf-8 -*-
import httplib2
import pprint

from apiclient.discovery import build
from apiclient.http import MediaFileUpload
from oauth2client.client import SignedJwtAssertionCredentials

# Email of the Service Account.
SERVICE_ACCOUNT_EMAIL = '@developer.gserviceaccount.com'

# Path to the Service Account's Private Key file.
SERVICE_ACCOUNT_PKCS12_FILE_PATH = '-privatekey.p12'


def createDriveService():
    f = file(SERVICE_ACCOUNT_PKCS12_FILE_PATH, 'rb')
    key = f.read()
    f.close()

    credentials = SignedJwtAssertionCredentials(SERVICE_ACCOUNT_EMAIL, key,
      scope='https://www.googleapis.com/auth/drive')
    http = httplib2.Http()
    http = credentials.authorize(http)

    return build('drive', 'v2', http=http)

FILENAME = 'document.txt'
drive_service = createDriveService()
media_body = MediaFileUpload(FILENAME, mimetype='text/plain', resumable=True)
body = {
  'title': 'My document',
  'description': 'A test document',
  'mimeType': 'text/plain'
}

file = drive_service.files().insert(body=body, media_body=media_body).execute()
pprint.pprint(file)

How to set the role of service account for this scenario?

As I remember I used this something like this https://developers.google.com/drive/api/v3/quickstart/python or this https://developers.google.com/identity/protocols/oauth2/service-account