def save(self):
        tmp_path = self.path + '.tmp'
        with open(tmp_path, 'w') as f:
            f.write(json.dumps(self.body_labels.items()))
        os.rename(tmp_path, self.path)
def getAp1(self):
        ret = math.acos(((self.getLenp2() * self.getLenp2() + self.getLenp3() * self.getLenp3()) - self.getLenp1() * self.getLenp1()) / (2* self.getLenp2() * self.getLenp3()))
        return ret