code: def nucleotidesToStr(nucleotides, prefix=''):
      
      result = []
      for offset in sorted(nucleotides):
          result.append(
              '%s%d: %s' % (prefix, offset,
                            baseCountsToStr(nucleotides[offset])))
      return '\n'.join(result)
docs: Convert offsets and base counts to a string.
  
      @param nucleotides: A C{defaultdict(Counter)} instance, keyed
          by C{int} offset, with nucleotides keying the Counters.
      @param prefix: A C{str} to put at the start of each line.
      @return: A C{str} representation of the offsets and nucleotide
          counts for each.