Chapter 8. Using Python and Mapnik to Generate Maps

Because geospatial data is almost impossible to understand until it is displayed, the creation of maps to visually represent spatial data is an extremely important topic. In this chapter we will look at Mapnik, a powerful Python library for generating maps out of geospatial data.

This chapter will cover the following:

• Underlying concepts used by Mapnik to generate maps

• Creating a simple map using the contents of a shapefile

• Different data sources that Mapnik supports

• Using rules, filters, and styles to control the map generation process

• Using "symbolizers" to draw lines, polygons, labels, points, and raster images onto your map

• Defining the colors used on a map

• Working with maps and layers

• Setting your options for rendering a map image

• The mapGenerator.py module, introduced in the previous chapter, uses Mapnik to generate maps

• Using map definition files to control and simplify the map-generation process