code: def summarize_taxa(biom):
      
      tamtcounts = defaultdict(int)
      tot_seqs = 0.0
  
      for row, col, amt in biom['data']:
          tot_seqs += amt
          rtax = biom['rows'][row]['metadata']['taxonomy']
          for i, t in enumerate(rtax):
              t = t.strip()
              if i == len(rtax)-1 and len(t) > 3 and len(rtax[-1]) > 3:
                  t = 's__'+rtax[i-1].strip().split('_')[-1]+'_'+t.split('_')[-1]
              tamtcounts[t] += amt
  
      lvlData = {lvl: levelData(tamtcounts, tot_seqs, lvl) for lvl in ['k', 'p', 'c', 'o', 'f', 'g', 's']}
  
      return tot_seqs, lvlData
docs: Given an abundance table, group the counts by every
      taxonomic level.