Remove the requirement for headsigns to be present, by inferring a he…

…adsign from the trip's last stop if one is not otherwise defined.

README.txt

@@ -29,7 +29,6 @@ for weekday and weekend service in the same run.
 tph.py requires that certain optional elements be present in the GTFS
 feed:
 * Trips must use the direction_id field
-* Headsigns must be defined in either the trip or stoptime
 
 Finally, do not be alarmed by long runtimes; transitfeed takes >5
 minutes to load large GTFS feeds. After the feed is loaded, each

find_service.py

@@ -33,6 +33,11 @@ def get_name_for_route(schedule, route_id):
             else:
                 return route_id
 
+def get_last_stop_name(schedule, trip):
+    stops = trip.GetStopTimes()
+    laststoptime = stops[-1]
+    return laststoptime.stop.stop_name
+
 
 def find_service(schedule, target_date, target_routes, target_stopid):
     #TODO: it would be good to validate that the given stop and routes exist.
@@ -69,7 +74,7 @@ def find_service(schedule, target_date, target_routes, target_stopid):
                         if stoptime.stop in target_stops:
                             hour = stoptime.arrival_time.split(':')[0]
                             count[int(hour) % 24] += 1
-                            headsigns[trip.trip_headsign or stoptime.stop_headsign] += 1
+                            headsigns[trip.trip_headsign or stoptime.stop_headsign or get_last_stop_name(schedule, trip)] += 1
 
             results_temp[route.route_id] = {'route_color': route.route_color,
                                             'route_name': get_name_for_route(schedule, route.route_id),