from mapnik import Map, Layer
proj4 = '+proj=sterea +lat_0=52.15616055555555 +lon_0=5.38763888888889 +k=0.9999079 +x_0=155000 +y_0=463000 +ellps=bessel +units=m +no_defs'
m = Map(256,256,proj4)
lyr = Layer('Name',proj4)