In this chapter, we had a brief introduction to the libraries and packages that we will use in this book. By installing these libraries, you also learned the general procedure of how to search and install Python packages. You can use this procedure in other cases whenever you feel the need for other libraries in your applications.
Then, we wrote code that made use of the OGR library to open a shapefile and perform area calculation and sorting. These simple procedures showed a little bit of the internal organization of OGR, how it handles geographic data, and how it is possible to extract information from them. In the next chapter, we will use some of the techniques learned here to read data and process vector points.