Is started building the GMT/Python interface in 2017 as part of my postdoc at the University of Hawaii with Prof Paul Wessel. Work is still in early stages but there is a minimum working example on the website. The library is Python 3 only and requires the latest development build of GMT (trunk of the SVN repository). We're striving for comprehensive test coverage and documentation.
I gave a talk about GMT/Python at Scipy 2017: