These APIs change regularly as google develops it's services, however the core activities should always work.
If you want to take advantage of the latest features, then the API might well be developing as I write this. However things like 'Uploading a pdf' should work and be stable ... or so I thought.
I repeat the text below for easy copy/paste for future web searching:
Loading ./cal_man_EL531_509refBySharp.pdf Failed to upload ./cal_man_EL531_509refBySharp.pdf: {'status': 415,
'body': 'Content-Type application/pdf is not a valid input type.',
'reason': 'Unsupported Media Type'}
Other types of file might work fine, however the lack of .pdf upload facility from command line, was enough to halt my experiment.
On Debian GNU/Linux the following install will help get you started:
apt-get install python-gdata googlecl