After some development, I think there's a version of pywikidata which works well enough to work with. It is still missing some features; however, creating items, getting them by id, and saving them is covered.
You can find it here (https://github.com/jcreus/pywikidata). The file example.py includes some examples of how it works.
Finally, in case you find bugs you're welcome to report them, even more to send a pull request ;). Pending things include handling permission errors (which some time ago I couldn't trigger, I'll try now), or getting items by interwiki.
Thanks a lot, and sorry for my English!