code: def cons(f, mindepth):
      
      C = ClustFile(f)
      for data in C:
          names, seqs, nreps = zip(*data)
          total_nreps = sum(nreps)
          # Depth filter
          if total_nreps < mindepth:
              continue
  
          S = []
          for name, seq, nrep in data:
              # Append sequence * number of dereps
              S.append([seq, nrep])
  
          # Make list for each site in sequences
          res = stack(S)
          yield [x[:4] for x in res if sum(x[:4]) >= mindepth]
docs: Makes a list of lists of reads at each site