code: def splitFASTA(params):
      
      assert params['fastaFile'][-1] == 'a', ('You must specify a file in '
                                              'fasta-format that ends in '
                                              '.fasta')
  
      fileCount = count = seqCount = 0
      outfp = None
      with open(params['fastaFile']) as infp:
          for seq in SeqIO.parse(infp, 'fasta'):
              seqCount += 1
              if count == params['seqsPerJob']:
                  outfp.close()
                  count = 0
              if count == 0:
                  outfp = open('%d.fasta' % fileCount, 'w')
                  fileCount += 1
              count += 1
              outfp.write('>%s\n%s\n' % (seq.description, str(seq.seq)))
      outfp.close()
      return fileCount, seqCount
docs: Read the FASTA file named params['fastaFile'] and print out its
      sequences into files named 0.fasta, 1.fasta, etc. with
      params['seqsPerJob'] sequences per file.