from mapnik import Map, Layer
proj4 = '+proj=tmerc +lat_0=53.5 +lon_0=-8 +k=1.000035 +x_0=200000 +y_0=250000 +a=6377340.189 +b=6356034.447938534 +units=m +no_defs'
m = Map(256,256,proj4)
lyr = Layer('Name',proj4)