google api discovery

from googleapiclient import discovery
HTTP = creds.authorize(Http())
DRIVE  = discovery.build('drive',   'v3', http=HTTP)
GCS    = discovery.build('storage', 'v1', http=HTTP)
VISION = discovery.build('vision',  'v1', http=HTTP)
SHEETS = discovery.build('sheets',  'v4', http=HTTP)

支持的服务和版本参见：
https://github.com/googleapis/google-api-python-client/blob/master/docs/dyn/index.md