First, in your Note, you're only utilizing the "title" and "body" fields. Whether this is compliant with the API is not immediately clear to me from their docs, so you may want to ensure you're not eliding any required fields.

Regardless, are you certain that service.notes().create accepts a python dictionary? I would bet the API provides a cleaner way to construct a Note object, or maybe just takes a JSON-formatted string; some other usages of the function seem to suggest the latter.