code: def write_ascii_series(series, output, **kwargs):
      
      xarr = series.xindex.value
      yarr = series.value
      return savetxt(output, column_stack((xarr, yarr)), **kwargs)
docs: Write a `Series` to a file in ASCII format
  
      Parameters
      ----------
      series : :class:`~gwpy.data.Series`
          data series to write
  
      output : `str`, `file`
          file to write to
  
      See also
      --------
      numpy.savetxt
          for documentation of keyword arguments