Executing a PostGIS ST_Buffer analysis query and exporting it to GeoJSON

Let's start by executing our first spatial analysis query from Python against our already running PostgreSQL and PostGIS database. The goal is to generate a 100 m buffer around all schools and export the new buffer polygon to GeoJSON, including the name of a school. The end result will be shown on this map, available (https://github.com/mdiener21/python-geospatial-analysis-cookbook/blob/master/ch04/geodata/out_buff_100m.geojson) on GitHub.

Tip

Quick visualizations of GeoJSON data using GitHub is a fast and simple way to create a web map without coding a single line. Note that the data is then free for everyone else to download if you are using a public and free GitHub account. Private GitHub accounts mean the data, that is, GeoJSON, will also remain private if data privacy or sensitivity is an issue.

Getting ready

To get started, we'll use our data in the PostGIS database. We will begin by accessing our schools...