PostGIS Programming - PostGIS - page 424

postgis_cookbook=# CREATE EXTENSION
pg_trgm;
CREATE EXTENSION
4. You will need to download some OSM datasets to use. Download the area
of your city/place or download the lazio.pbf OSM file from ht-
tp://download.gfoss.it/osm/osm/regioni/ ifyouwanttogowiththerecipeand
getsimilarresults(youcanfindacopyofthisfileinthe data/chp08 book's
dataset directory).
5. IfyouareusingWindows,besuretohaveinstalledtheOSGeo4Wsuiteas
suggested in the initial instructions of this chapter.
6. IfyouareusingLinux,followtheinitialinstructionsofthischapterandcreate
aPythonvirtualenvironmentinordertokeepaPython-isolatedenvironment
to be used for all the Python recipes of this topic. Then activate it as follows:
$ source postgis-cb-env/bin/activate
7. Oncetheenvironmenthasbeenactivated,ifyoustillhaven'tdoneit,youcan
install the Python packages needed for this recipe:
(postgis-cb-env)$ pip install gdal
(postgis-cb-env)$ pip install psycopg2
How to do it...
Carry out the following steps:
1. First,checkouthowtheOSM .pbf fileisbuiltusing ogrinfo .PBFisabin-
ary format intended as an alternative to the OSM XML format, mainly be-
causeitismuchsmaller.Asyoumusthavenoticed,itiscomposedofseveral
layers—youwillexportthe lines layertoPostGISasthatlayercontainsthe
street names that you will use for the overall geocoding process:
$ ogrinfo lazio.pbfHad to open data
source read-only.INFO: Open of
`lazio.pbf'using driver `OSM'
successful.1: points (Point)2: lines
(Line String)3: multilinestrings (Multi