This issue was initially reported here.

There is issue with the BatchJobService in Python 3 where an AttributeError is raised in the _GetRawOperationsFromXML method in this line:

root = ElementTree.fromstring(raw_request_xml.encode('utf-8'))

This will work in Python 2 because str has an encode method, whereas Python 3's bytes does not.

We'll try to sneak this in to an upcoming release and close this issue when it is out.