code: def set_features(self):
          
          self.scores = {}
          for t_or_d, feats in zip(['target', 'decoy'], [self.target,
                                                         self.decoy]):
              self.scores[t_or_d] = {}
              self.scores[t_or_d]['scores'] = self.score_get_fun(
                  feats, self.featuretype, self.prepare_percolator_output)
              self.scores[t_or_d]['fn'] = '{}_qvality_input.txt'.format(t_or_d)
              writers.write_qvality_input(self.scores[t_or_d]['scores'],
                                          self.scores[t_or_d]['fn'])
docs: Creates scorefiles for qvality's target and decoy distributions