code: def binned_bitsets_from_list( list=[] ):
      
      last_chrom = None
      last_bitset = None
      bitsets = dict()
      for l in list:
          chrom = l[0]
          if chrom != last_chrom:
              if chrom not in bitsets:
                  bitsets[chrom] = BinnedBitSet(MAX)
              last_chrom = chrom
              last_bitset = bitsets[chrom]
          start, end = int( l[1] ), int( l[2] )
          last_bitset.set_range( start, end - start )
      return bitsets
docs: Read a list into a dictionary of bitsets