code: def write_matrix(outputfile, matrix):
      
  
      try:
          stream = open(outputfile, 'w')
          for row in matrix:
              if isinstance(row, list) or isinstance(row, tuple):
                  row = [str(el).strip() for el in row]
                  stream.write(','.join(row) + '\n')
              else:
                  stream.write(row + '\n')
      except IOError as err:  # pragma: no cover
          LOG.info('An error occured while writing the file %s'
                   % outputfile)
          LOG.debug("Error: %s" % err)
      finally:
          stream.close()
      LOG.info('Wrote QTLs in file %s' % outputfile)
docs: Write down the provided matrix in the specified outputfile.
      :arg outputfile, name of the outputfile in which the QTLs found are
          written.
      :arg matrix, the list of lists of data to write.