set legend location

def set_legend_location(self, loc, onaxis):
        "set legend location"
        self.legend_onaxis = 'on plot'
        if not onaxis:
            self.legend_onaxis = 'off plot'
            if loc == 'best':
                loc = 'upper right'
        if loc in self.legend_abbrevs:
            loc = self.legend_abbrevs[loc]
        if loc in self.legend_locs:
            self.legend_loc = loc