old_contents: import os
  import psycopg2
  
  #Take an roads.geojson, and make a many polygons beetwen roads in osm format.
  #Open OSM file in JOSM, and you get a fancy medium-zoom landuse map
  
  
  def process():
  	dbname='residential'
  	user='user'
  	host='localhost'
  	password='user'
  	try:
  		conn = psycopg2.connect("dbname='" + dbname + "' user='"
                                  + user + "' host='" + host
                                  + "' password='" + password + "'")
  	except:
  		print 'I am unable to connect to the database'
  		return 0
  	cur = conn.cursor()
  	sql ='''
  	DROP TABLE IF EXISTS roads;
  	DROP TABLE IF EXISTS areas;
  	DROP TABLE IF EXISTS areas_singlegeom;
  	
  	'''
  
  	cur.execute(sql)
  	conn.commit()
  
  
  	os.system('''
  	ogr2ogr -overwrite -f "PostgreSQL" PG:"host=localhost user=user dbname=residential password=user"  -nln roads roads.geojson -s_srs EPSG:4326 -t_srs EPSG:3857
  	''')
  
  	
  
  
  	sql='''
  	CREATE TABLE areas AS
  	SELECT 
  	1 AS id,	
  	ST_Difference(
  		ST_ConvexHull(ST_Collect(wkb_geometry)),
  		ST_Buffer(ST_Collect(wkb_geometry),10)
  		)
  		AS poly
  	
  	FROM roads;
  
  	CREATE TABLE areas_singlegeom AS
  	SELECT
  	ST_GeometryN(poly,generate_series(1,ST_NumGeometries(poly))) AS geom,
  	'residential' AS landuse,
  	'highway buffers' AS source
  	FROM areas;
  	'''
  	cur.execute(sql)
  	conn.commit()
  
  	os.system('''
  	ogr2ogr -overwrite data PG:"dbname='residential' host='localhost' port='5432' user='user' password='user'"  "areas_singlegeom" -nlt MULTIPOLYGON -s_srs EPSG:3857 -t_srs EPSG:4326
  	''')
  
  	os.system('''
  	rm areas_singlegeom.osm
  	''')
  
  	os.system('''
  python ogr2osm/ogr2osm.py data/areas_singlegeom.shp
  	''')
  
  if __name__ == '__main__':
  	process()
  
new_contents: import os
  import psycopg2
  
  #Take an roads.geojson, and make a many polygons beetwen roads in osm format.
  #Open OSM file in JOSM, and you get a fancy medium-zoom landuse map
  
  
  def process():
  	dbname='gis'
  	user='user'
  	host='localhost'
  	password='user'
  	try:
  		conn = psycopg2.connect("dbname='" + dbname + "' user='"
                                  + user + "' host='" + host
                                  + "' password='" + password + "'")
  	except:
  		print 'I am unable to connect to the database'
  		return 0
  	cur = conn.cursor()
  	sql ='''
  	DROP TABLE IF EXISTS roads;
  	DROP TABLE IF EXISTS areas;
  	DROP TABLE IF EXISTS areas_singlegeom;
  	
  	'''
  
  	cur.execute(sql)
  	conn.commit()
  
  
  	os.system('''
  	ogr2ogr -overwrite -f "PostgreSQL" PG:"host=localhost user=user dbname=gis password=user"  -nln roads roads.geojson -s_srs EPSG:4326 -t_srs EPSG:3857
  	''')
  
  	
  
  
  	sql='''
  	CREATE TABLE areas AS
  	SELECT 
  	1 AS id,	
  	ST_Difference(
  		ST_ConvexHull(ST_Collect(wkb_geometry)),
  		ST_Buffer(ST_Collect(wkb_geometry),10)
  		)
  		AS poly
  	
  	FROM roads;
  
  	CREATE TABLE areas_singlegeom AS
  	SELECT
  	ST_GeometryN(poly,generate_series(1,ST_NumGeometries(poly))) AS geom,
  	'residential' AS landuse,
  	'highway buffers' AS source
  	FROM areas;
  	'''
  	cur.execute(sql)
  	conn.commit()
  
  	os.system('''
  	ogr2ogr -overwrite data PG:"dbname='residential' host='localhost' port='5432' user='user' password='user'"  "areas_singlegeom" -nlt MULTIPOLYGON -s_srs EPSG:3857 -t_srs EPSG:4326
  	''')
  
  	os.system('''
  	rm areas_singlegeom.osm
  	''')
  
  	os.system('''
  python ogr2osm/ogr2osm.py data/areas_singlegeom.shp
  	''')
  
  if __name__ == '__main__':
  	process()
  
subject: Update main.py