from mapscript import mapObj,layerObj wkt = '''GEOGCS["GCS_Canton_1966",DATUM["Canton_1966",SPHEROID["International_1924",6378388,297]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295],AUTHORITY["EPSG","37216"]]''' m = mapObj('') m.setWKTProjection(wkt) lyr = layerObj(m) lyr.setWKTProjection(wkt)