from mapnik import Map, Layer
proj4 = '+proj=tmerc +lat_0=-39.13575830555556 +lon_0=174.22801175 +k=1 +x_0=300000 +y_0=700000 +ellps=intl +datum=nzgd49 +units=m +no_defs'
m = Map(256,256,proj4)
lyr = Layer('Name',proj4)