====== Google gdata ======

===== oauth2 =====
  * https://developers.google.com/api-client-library/python/auth/web-app
  * http://google.github.io/oauth2client/
  * Example： http://stackoverflow.com/questions/13812813/oauth2-authentication-in-gae-accessing-calendar-api-v3-domain-hosted

<code>
# http://stackoverflow.com/questions/15493062/store-access-token-from-google-oauth-2-0-to-access-drive-data-from-application-a
oauth2client.appengine.StorageByKeyName:

from oauth2client.keyring_storage import StorageByKeyName
from oauth2client.keyring_storage import CredentialsNDBModel
...
storage = StorageByKeyName(CredentialsNDBModel, some_user_id, 'credentials')
storage.put(credentials)
...
credentials = storage.get()

</code>