A tool to parse the OSM API's list of expired z12 tiles and delete the corresponding tiles in a TileStache disk cache.

expire_tiles.py

#!/bin/python

import sys
import xml.etree.cElementTree as ET
import urllib2

# Expire tiles in a TileStache default file cache based on the OpenStreetMap server's z12 change output
# at http://www.openstreetmap.org/api/0.6/changes

maxZoom = 19

if len(sys.argv) < 2:
    print 'Missing tile cache root path argument.'
    sys.exit(1)

rootPath = sys.argv[1]

urlstream = urllib2.urlopen('http://www.openstreetmap.org/api/0.6/changes')

def deleteZoom(z, x, y):
    xStr = str(x).zfill(9)
    yStr = str(y).zfill(9)
    path = "%s/%02d/%s/%s/%s/%s/%s/%s.png" % (rootPath,
                                              z,
                                              xStr[0:3], xStr[3:6], xStr[6:9],
                                              yStr[0:3], yStr[3:6], yStr[6:9])
    print path

    if z == maxZoom:
        return

    # delete subtiles
    deleteZoom(z + 1, 2*x  , 2*y  )
    deleteZoom(z + 1, 2*x+1, 2*y  )
    deleteZoom(z + 1, 2*x  , 2*y+1)
    deleteZoom(z + 1, 2*x+1, 2*y+1)

for event, elem in ET.iterparse(urlstream, events=('start',)):
    if elem.tag == "tile":
        z12z = int(elem.attrib['z'])
        z12x = int(elem.attrib['x'])
        z12y = int(elem.attrib['y'])

        deleteZoom(z12z, z12x, z12y)

    elem.clear()