found a bug in nsga3.py

[weihongjing]

    pop = self.pop[I]
    print(pop.shape)
    print(self.pop.get("is_closest"))
    if len(pop) == 1:
        self.opt = pop
    else:
        self.opt = pop[self.pop.get("is_closest")]

here the last line should be
self.opt = self.pop[self.pop.get("is_closest")]

[blankjul]

Thanks for your comment. Also, infeasible solutions would have been returned if the problem has constrains.
It should be fixed in the new release 0.3.1. Please let me know if your test case works now!