code: def get_marker_indices(marker,line):
      
      indices = [i for i, ltr in enumerate(line) if ltr == marker]
      start = indices[0:-1:2]
      end = [i+1 for i in indices[1::2]]
      assert len(start) == len(end)
      return start,end
docs: method to find the start and end parameter markers
      on a template file line.  Used by write_to_template()
  
      Parameters
      ----------
      marker : str
          template file marker char
      line : str
          template file line
  
      Returns
      -------
      indices : list
          list of start and end indices (zero based)