code: def select_samples(dbsamples, samples, pidx=None):
      
      ## get index from dbsamples
      samples = [i.name for i in samples]
      if pidx:
          sidx = [list(dbsamples[pidx]).index(i) for i in samples]
      else:
          sidx = [list(dbsamples).index(i) for i in samples]
      sidx.sort()
      return sidx
docs: Get the row index of samples that are included. If samples are in the
      'excluded' they were already filtered out of 'samples' during _get_samples.