from mapnik import Map, Layer
proj4 = '+proj=lcc +lat_1=27.5 +lat_2=35 +lat_0=18 +lon_0=-100 +x_0=1500000 +y_0=5000000 +ellps=GRS80 +units=m +no_defs'
m = Map(256,256,proj4)
lyr = Layer('Name',proj4)