code: def replace_lines_in_files(search_string, replacement_line):
      
  
  
      # have the user select some files
      paths = _s.dialogs.MultipleFiles('DIS AND DAT|*.*')
      if paths == []: return
  
      for path in paths:
          _shutil.copy(path, path+".backup")
          lines = read_lines(path)
          for n in range(0,len(lines)):
              if lines[n].find(search_string) >= 0:
                  print(lines[n])
                  lines[n] = replacement_line.strip() + "\n"
          write_to_file(path, join(lines, ''))
  
      return
docs: Finds lines containing the search string and replaces the whole line with
      the specified replacement string.