def METHOD_NAME(self, source_file, dest_file):
    with open(source_file, 'rb') as fp:
        lines = fp.readlines()
    nl = lines[0][len(lines[0].strip()):]
    with open(dest_file, 'wb') as fp:
        fp.writelines(lines[:lines.index(b"#--start keywords--" + nl) + 1])
        fp.writelines(lines[lines.index(b"#--end keywords--" + nl):])