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"""Transitland Schedule API: create GeoJSON map of transit frequency.""" |
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import json |
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import urllib |
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import urllib2 |
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import datetime |
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import math |
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import os |
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########################################################## |
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##### Transitland Datastore Interface ##### |
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########################################################## |
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class Datastore(object): |
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"""A simple interface to the Transitland Datastore.""" |
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def __init__(self, host): |
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self.host = host |
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def _request(self, uri): |
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print uri |
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req = urllib2.Request(uri) |
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req.add_header('Content-Type', 'application/json') |
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response = urllib2.urlopen(req) |
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return json.loads(response.read()) |
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def request(self, endpoint, **data): |
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"""Request with JSON response.""" |
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return self._request( |
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'%s%s?%s'%(self.host, endpoint, urllib.urlencode(data or {})) |
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) |
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def paginated(self, endpoint, key, **data): |
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"""Request with paginated JSON response. Returns generator.""" |
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response = self.request(endpoint, **data) |
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while response: |
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meta = response['meta'] |
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print '%s: %s -> %s of %s'%( |
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key, |
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meta['offset'], |
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meta['offset']+meta['per_page'], |
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meta['total'] |
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) |
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for entity in response[key]: |
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yield entity |
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if meta.get('next'): |
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response = self._request(meta.get('next')) |
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else: |
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response = None |
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def schedule_stop_pairs(self, **data): |
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"""Request Schedule Stop Pairs.""" |
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return self.paginated( |
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'/api/v1/schedule_stop_pairs', |
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'schedule_stop_pairs', |
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**data |
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) |
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def stops(self, **data): |
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"""Request Stops""" |
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return self.paginated( |
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'/api/v1/stops', |
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'stops', |
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**data |
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) |
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def stop(self, onestop_id): |
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"""Request a Stop by Onestop ID.""" |
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return self.request('/api/v1/stops/%s'%onestop_id) |
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def duration(t1, t2): |
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"""Return the time between two HH:MM:SS times, in seconds.""" |
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fmt = '%H:%M:%S' |
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t1 = datetime.datetime.strptime(t1, fmt) |
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t2 = datetime.datetime.strptime(t2, fmt) |
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return (t2 - t1).seconds |
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########################################################## |
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##### Count trips between stops, output GeoJSON ##### |
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########################################################## |
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HOST = 'http://transit.land' |
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PER_PAGE = 1000 |
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BBOX = [ |
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-122.554, |
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37.668, |
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-122.085, |
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37.912 |
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] |
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DATE = '2015-10-26' |
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BETWEEN = [ |
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'07:00:00', |
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'09:00:00' |
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] |
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HOURS = duration(BETWEEN[0], BETWEEN[1]) / 3600.0 |
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# Minimum vehicles per hour |
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# http://colorbrewer2.org/ |
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COLORMAP = { |
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0: '#fef0d9', |
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3: '#fdcc8a', |
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6: '#fc8d59', |
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10: '#d7301f' |
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} |
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OUTFILE = 'output.geojson' |
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if os.path.exists(OUTFILE): |
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raise Exception("File exists: %s"%OUTFILE) |
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# Transitland Datastore API |
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ds = Datastore(HOST) |
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# Group SSPs by (origin, destination) and count |
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edges = {} |
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ssps = ds.schedule_stop_pairs( |
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bbox=','.join(map(str, BBOX)), |
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origin_departure_between=','.join(BETWEEN), |
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date=DATE, |
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per_page=PER_PAGE |
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) |
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for ssp in ssps: |
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key = ssp['origin_onestop_id'], ssp['destination_onestop_id'] |
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if key not in edges: |
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edges[key] = 0 |
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edges[key] += 1 |
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# Get Stop geometries |
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stops = {} |
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for stop in ds.stops(per_page=PER_PAGE, bbox=','.join(map(str, BBOX))): |
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stops[stop['onestop_id']] = stop |
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# Create GeoJSON Features |
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colorkeys = sorted(COLORMAP.keys()) |
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features = [] |
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edges_sorted = sorted(edges.items(), key=lambda x:x[1]) |
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for (origin_onestop_id,destination_onestop_id),trips in edges_sorted: |
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# Origin and destination geometries |
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origin = stops.get(origin_onestop_id) |
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destination = stops.get(destination_onestop_id) |
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if not (origin and destination): |
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# Outside bounding box |
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continue |
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# Frequency is in trips per hour |
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frequency = trips / HOURS |
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frequency_class = [i for i in colorkeys if frequency >= i][-1] |
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print "Origin: %s Destination: %s Trips: %s Frequency: %s Freq. class: %s"%( |
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origin_onestop_id, |
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destination_onestop_id, |
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trips, |
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frequency, |
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frequency_class |
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) |
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# Create the GeoJSON Feature |
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features.append({ |
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"type": "Feature", |
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"name": "%s -> %s"%(origin['name'], destination['name']), |
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"properties": { |
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"origin_onestop_id": origin_onestop_id, |
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"destination_onestop_id": destination_onestop_id, |
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"trips": trips, |
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"frequency": frequency, |
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"frequency_class": frequency_class, |
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"stroke": COLORMAP[frequency_class], |
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"stroke-width": frequency_class+1, |
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"stroke-opacity": 1.0 |
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}, |
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"geometry": { |
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"type": "LineString", |
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"coordinates": [ |
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origin['geometry']['coordinates'], |
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destination['geometry']['coordinates'] |
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] |
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} |
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}) |
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# Create the GeoJSON Feature Collection |
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fc = { |
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"type": "FeatureCollection", |
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"features": features |
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} |
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with open(OUTFILE, 'wb') as f: |
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json.dump(fc, f) |
Hi,
I would like to use this lovely code for another area and for another date and I have used this code, but I have this error:
I do not what's wrong. Could you help me?
Thank you