Goal: To use spatial databases to perform operations such as centroid, nearest point, and distances to generate a table of distances along a road network from area to area, using the nearest node to the centroid of an area to represent the area.
Backup plan: Create a list of nearest node to centroid of areas. Use some code I have previously written in R to implement Dijkstra's algorithm.
Preferred method: Programmatically access Spatialite and perform all functions in spatialite.
Barrier: Most distributions of SQLite (including the sqlite3 library included in Python) do not enable loading of extentions.
Solution: Install Python module pyspatialite.
Installing pyspatialite is done through easy_install: sudo python setup.py install
The documentation mentions that you need geos and proj libraries installed. What it does not tell you is that you need the development versions (which include header files) of these libraries, as well as the Python headers. After installing the developmental files, then you can install pyspatialite.