Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
OSM to networkx graph with node coordinates ;-)
"""
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
#"""
@ridhoperdana

This comment has been minimized.

Copy link

ridhoperdana commented Dec 9, 2016

Hi, rajanski, what a great code you have here.

I want to ask something, how can i use/export the graph generated from this script to a database or somekind of file which i can read externally? Or could you give some suggestion?

I am on my last year of bachelor degree and my last project is to use my own code algorithm (not like using pgrouting) to create a route with map and graph data from openstreetmap. I am a newbie on this map and friend thing.

@RiyaUplenchwar

This comment has been minimized.

Copy link

RiyaUplenchwar commented Jan 6, 2017

I am trying to run this code on windows. but not able to run. when I had done F5 to run the program it doesn't return me anything except the Idle shell. will you plzz share me the complete commands to run the program. Thank you.

@luizcartolano2

This comment has been minimized.

Copy link

luizcartolano2 commented Jul 26, 2018

How can I use this code?

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.