I tried upgrading to 0.3.0, and no I get a ConfigurationError from pymongo when I use MONGO_READ_PREFERENCE = ReadPreference.PRIMARY. It seems to be because of the trailing comma on https://github.com/dcrosta/flask-pymongo/blob/master/flask_pymongo/__init__.py#L210 causing flask_pymongo to send a tuple to pymongo.
I tried upgrading to 0.3.0, and no I get a ConfigurationError from pymongo when I use MONGO_READ_PREFERENCE = ReadPreference.PRIMARY. It seems to be because of the trailing comma on https://github.com/dcrosta/flask-pymongo/blob/master/flask_pymongo/__init__.py#L210 causing flask_pymongo to send a tuple to pymongo.