from mapnik import Map, Layer
proj4 = '+proj=cass +lat_0=11.25217861111111 +lon_0=-60.68600888888889 +x_0=37718.66159325 +y_0=36209.91512952 +a=6378293.645208759 +b=6356617.987679838 +to_meter=0.201166195164 +no_defs'
m = Map(256,256,proj4)
lyr = Layer('Name',proj4)