Mastering Geospatial Analysis with Python

Incidents by date

One of the ways you can limit the results of an incident query is by date. Using the Python datetime library, you can specify a date, then query incidents on that date, and get the geometry of the results as GeoJSON and add it to your map:

d=datetime.datetime.strptime('201781','%Y%m%d').date() cursor.execute("SELECT address,crimetype,date,ST_AsGeoJSON(geom) from incidents where date ='{}' ".format(str(d)))incidents_date=cursor.fetchall()for x in incidents_date:    layer=json.loads(x[3])    layergeojson=GeoJSON(data=layer)    map.add_layer(layergeojson)

The previous code specifies a date (YYYYMD) of August 1, 2017. It queries the incidents table we're using, where date = d and returns the geometry as GeoJSON. It then uses the for ...