OSM to networkx graph with node coordinates ;-)

gistfile1.py

"""
Read graphs in Open Street Maps osm format
Based on osm.py from brianw's osmgeocode
http://github.com/brianw/osmgeocode, which is based on osm.py from
comes from Graphserver:
http://github.com/bmander/graphserver/tree/master and is copyright (c)
2007, Brandon Martin-Anderson under the BSD License
"""

import xml.sax
import copy
import networkx

#highway_cat = 'motorway|trunk|primary|secondary|tertiary|road|residential|service|motorway_link|trunk_link|primary_link|secondary_link|teriary_link'

def download_osm(left,bottom,right,top,highway_cat):
    """
    Downloads OSM street (only highway-tagged) Data using a BBOX, 
    plus a specification of highway tag values to use

    Parameters
    ----------
    left,bottom,right,top : BBOX of left,bottom,right,top coordinates in WGS84
    highway_cat : highway tag values to use, separated by pipes (|), for instance 'motorway|trunk|primary'

    Returns
    ----------
    stream object with osm xml data

    """

    #Return a filehandle to the downloaded data."""
    from urllib import urlopen
    #fp = urlopen( "http://api.openstreetmap.org/api/0.6/map?bbox=%f,%f,%f,%f"%(left,bottom,right,top) )
    #fp = urlopen( "http://www.overpass-api.de/api/xapi?way[highway=*][bbox=%f,%f,%f,%f]"%(left,bottom,right,top) )
    print "trying to download osm data from "+str(left),str(bottom),str(right),str(top)+" with highways of categories"+highway_cat
    try:    
        print "downloading osm data from "+str(left),str(bottom),str(right),str(top)+" with highways of categories"+highway_cat
        fp = urlopen( "http://www.overpass-api.de/api/xapi?way[highway=%s][bbox=%f,%f,%f,%f]"%(highway_cat,left,bottom,right,top) )
        #slooww only ways,and in ways only "highways" (i.e. roads)
        #fp = urlopen( "http://open.mapquestapi.com/xapi/api/0.6/way[highway=*][bbox=%f,%f,%f,%f]"%(left,bottom,right,top) )
        return fp
    except:
        print "osm data download unsuccessful"

def read_osm(filename_or_stream, only_roads=True):
    """Read graph in OSM format from file specified by name or by stream object.

    Parameters
    ----------
    filename_or_stream : filename or stream object

    Returns
    -------
    G : Graph

    Examples
    --------
    >>> G=nx.read_osm(nx.download_osm(-122.33,47.60,-122.31,47.61))
    >>> plot([G.node[n]['data'].lat for n in G], [G.node[n]['data'].lon for n in G], ',')

    """
    osm = OSM(filename_or_stream)
    G = networkx.DiGraph()
 
    for w in osm.ways.itervalues():
        if only_roads and 'highway' not in w.tags:
            continue
        G.add_path(w.nds, id=w.id, highway = w.tags['highway'], street= w.tags['name'])#{str(k): type(v) for k,v in w.tags.items()})
        
        if 'oneway' not in w.tags and  w.tags['highway'] != 'motorway':
            G.add_path(reversed(w.nds), id= '-' + str(w.id), highway = w.tags['highway'], street= w.tags['name'])

        elif w.tags['oneway'] != 'yes' and w.tags['oneway'] != '-1' and  w.tags['highway'] != 'motorway':
            G.add_path(reversed(w.nds), id=w.id, highway = w.tags['highway'], street= w.tags['name'])

        
    for n_id in G.nodes_iter():
        n = osm.nodes[n_id]
        G.node[n_id] = dict(lon=n.lon,lat=n.lat)
    return G
        
    
class Node:
    def __init__(self, id, lon, lat):
        self.id = id
        self.lon = lon
        self.lat = lat
        self.tags = {}
        
class Way:
    def __init__(self, id, osm):
        self.osm = osm
        self.id = id
        self.nds = []
        self.tags = {}
        
    def split(self, dividers):
        # slice the node-array using this nifty recursive function
        def slice_array(ar, dividers):
            for i in range(1,len(ar)-1):
                if dividers[ar[i]]>1:
                    #print "slice at %s"%ar[i]
                    left = ar[:i+1]
                    right = ar[i:]
                    
                    rightsliced = slice_array(right, dividers)
                    
                    return [left]+rightsliced
            return [ar]
            


        slices = slice_array(self.nds, dividers)
        
        # create a way object for each node-array slice
        ret = []
        i=0
        for slice in slices:
            littleway = copy.copy( self )
            littleway.id += "-%d"%i
            littleway.nds = slice
            ret.append( littleway )
            i += 1
            
        return ret
        
        
 
class OSM:
    def __init__(self, filename_or_stream):
        """ File can be either a filename or stream/file object."""
        nodes = {}
        ways = {}
        
        superself = self
        
        class OSMHandler(xml.sax.ContentHandler):
            @classmethod
            def setDocumentLocator(self,loc):
                pass
            
            @classmethod
            def startDocument(self):
                pass
                
            @classmethod
            def endDocument(self):
                pass
                
            @classmethod
            def startElement(self, name, attrs):
                if name=='node':
                    self.currElem = Node(attrs['id'], float(attrs['lon']), float(attrs['lat']))
                elif name=='way':
                    self.currElem = Way(attrs['id'], superself)
                elif name=='tag':
                    self.currElem.tags[attrs['k']] = attrs['v']
                elif name=='nd':
                    self.currElem.nds.append( attrs['ref'] )
                
            @classmethod
            def endElement(self,name):
                if name=='node':
                    nodes[self.currElem.id] = self.currElem
                elif name=='way':
                    ways[self.currElem.id] = self.currElem
                
            @classmethod
            def characters(self, chars):
                pass
 
        xml.sax.parse(filename_or_stream, OSMHandler)
        
        self.nodes = nodes
        self.ways = ways
        #"""   
        #count times each node is used
        node_histogram = dict.fromkeys( self.nodes.keys(), 0 )
        for way in self.ways.values():
            if len(way.nds) < 2:       #if a way has only one node, delete it out of the osm collection
                del self.ways[way.id]
            else:
                for node in way.nds:
                    node_histogram[node] += 1
        
        #use that histogram to split all ways, replacing the member set of ways
        new_ways = {}
        for id, way in self.ways.iteritems():
            split_ways = way.split(node_histogram)
            for split_way in split_ways:
                new_ways[split_way.id] = split_way
        self.ways = new_ways
        #"""

    

How can I use this code?