from mapscript import mapObj,layerObj
wkt = '''PROJCS["unnamed",GEOGCS["unnamed ellipse",DATUM["unknown",SPHEROID["unnamed",6371000,0]],PRIMEM["Greenwich",0],UNIT["degree",0.0174532925199433]],PROJECTION["Mercator_1SP"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",0],PARAMETER["scale_factor",1],PARAMETER["false_easting",1000],PARAMETER["false_northing",1000],UNIT["km",1]]'''
m = mapObj('')
m.setWKTProjection(wkt)
lyr = layerObj(m)
lyr.setWKTProjection(wkt)