You can pass a reference arg to the Treatment contrast.

http://patsy.readthedocs.org/en/latest/API-reference.html#patsy.Treatment

If you have a better suggestion for naming conventions please file an issue with patsy.

You can pass a reference arg to the Treatment contrast, using syntax like

"y ~ C(Location, Treatment(reference='China'))"

http://patsy.readthedocs.org/en/latest/API-reference.html#patsy.Treatment

If you have a better suggestion for naming conventions please file an issue with patsy.