Added TODO List and a utility to convert a GTFS folder to a Pandas

Dataframe and check the validity of the feed.

transport_accessibility/pt_map/gtfs.py

@@ -0,0 +1,149 @@
+import pandas as pd
+
+class GTFS:
+    def __init__(self, folder_path):
+        self.folder_path = folder_path
+        self.agency = self.Agency(self.folder_path)
+        self.stops = self.Stops(self.folder_path)
+        self.routes = self.Routes(self.folder_path)
+        self.trips = self.Trips(self.folder_path)
+        self.stop_times = self.StopTimes(self.folder_path)
+        self.calendar = self.Calendar(self.folder_path)
+        self.calendar_dates = self.CalendarDates(self.folder_path)
+        self.fare_attributes = self.FareAttributes(self.folder_path)
+        self.fare_rules = self.FareRules(self.folder_path)
+        self.shapes = self.Shapes(self.folder_path)
+        self.frequencies = self.Frequencies(self.folder_path)
+        self.transfers = self.Transfers(self.folder_path)
+        self.feed_info = self.FeedInfo(self.folder_path)
+        self.errors = []
+    
+    class GTFSFile:
+        def __init__(self, folder_path, file_name):
+            self.file_path = f"{folder_path}/{file_name}.txt"
+            self.data = self.load_data()
+
+        def load_data(self):
+            try:
+                return pd.read_csv(self.file_path)
+            except FileNotFoundError:
+                return None
+
+    class Agency(GTFSFile):
+        def __init__(self, folder_path):
+            super().__init__(folder_path, 'agency')
+
+    class Stops(GTFSFile):
+        def __init__(self, folder_path):
+            super().__init__(folder_path, 'stops')
+
+    class Routes(GTFSFile):
+        def __init__(self, folder_path):
+            super().__init__(folder_path, 'routes')
+
+    class Trips(GTFSFile):
+        def __init__(self, folder_path):
+            super().__init__(folder_path, 'trips')
+
+    class StopTimes(GTFSFile):
+        def __init__(self, folder_path):
+            super().__init__(folder_path, 'stop_times')
+
+    class Calendar(GTFSFile):
+        def __init__(self, folder_path):
+            super().__init__(folder_path, 'calendar')
+
+    class CalendarDates(GTFSFile):
+        def __init__(self, folder_path):
+            super().__init__(folder_path, 'calendar_dates')
+
+    class FareAttributes(GTFSFile):
+        def __init__(self, folder_path):
+            super().__init__(folder_path, 'fare_attributes')
+
+    class FareRules(GTFSFile):
+        def __init__(self, folder_path):
+            super().__init__(folder_path, 'fare_rules')
+
+    class Shapes(GTFSFile):
+        def __init__(self, folder_path):
+            super().__init__(folder_path, 'shapes')
+
+    class Frequencies(GTFSFile):
+        def __init__(self, folder_path):
+            super().__init__(folder_path, 'frequencies')
+
+    class Transfers(GTFSFile):
+        def __init__(self, folder_path):
+            super().__init__(folder_path, 'transfers')
+
+    class FeedInfo(GTFSFile):
+        def __init__(self, folder_path):
+            super().__init__(folder_path, 'feed_info')
+
+    def validate(self):
+        self.validate_agency()
+        self.validate_stops()
+        self.validate_routes()
+        self.validate_trips()
+        self.validate_stop_times()
+        self.validate_calendar()
+        self.validate_cross_references()
+        
+        if not self.errors:
+            return None
+        else:
+            return self.errors
+
+    def validate_agency(self):
+        required_fields = ["agency_id", "agency_name", "agency_url", "agency_timezone"]
+        self.validate_required_fields(self.agency.data, required_fields, "agency.txt")
+
+    def validate_stops(self):
+        required_fields = ["stop_id", "stop_name", "stop_lat", "stop_lon"]
+        self.validate_required_fields(self.stops.data, required_fields, "stops.txt")
+        self.validate_lat_lon(self.stops.data)
+
+    def validate_routes(self):
+        required_fields = ["route_id", "route_short_name", "route_long_name", "route_type"]
+        self.validate_required_fields(self.routes.data, required_fields, "routes.txt")
+
+    def validate_trips(self):
+        required_fields = ["route_id", "service_id", "trip_id"]
+        self.validate_required_fields(self.trips.data, required_fields, "trips.txt")
+
+    def validate_stop_times(self):
+        required_fields = ["trip_id", "arrival_time", "departure_time", "stop_id", "stop_sequence"]
+        self.validate_required_fields(self.stop_times.data, required_fields, "stop_times.txt")
+
+    def validate_calendar(self):
+        required_fields = ["service_id", "monday", "tuesday", "wednesday", "thursday", "friday", "saturday", "sunday", "start_date", "end_date"]
+        self.validate_required_fields(self.calendar.data, required_fields, "calendar.txt")
+
+    def validate_required_fields(self, data, required_fields, filename):
+        for field in required_fields:
+            if field not in data.columns:
+                self.errors.append(f"Error: {filename} missing required field: {field}")
+
+    def validate_lat_lon(self, data):
+        for index, row in data.iterrows():
+            if not (-90 <= row['stop_lat'] <= 90):
+                self.errors.append(f"Error: stops.txt invalid latitude at row {index}: {row['stop_lat']}")
+            if not (-180 <= row['stop_lon'] <= 180):
+                self.errors.append(f"Error: stops.txt invalid longitude at row {index}: {row['stop_lon']}")
+
+    def validate_cross_references(self):
+        # Validate that trip_ids in stop_times.txt exist in trips.txt
+        stop_times_trip_ids = set(self.stop_times.data['trip_id'])
+        trips_trip_ids = set(self.trips.data['trip_id'])
+        missing_trip_ids = stop_times_trip_ids - trips_trip_ids
+        for trip_id in missing_trip_ids:
+            self.errors.append(f"Error: trip_id {trip_id} in stop_times.txt does not exist in trips.txt")
+        
+        # Validate that stop_ids in stop_times.txt exist in stops.txt
+        stop_times_stop_ids = set(self.stop_times.data['stop_id'])
+        stops_stop_ids = set(self.stops.data['stop_id'])
+        missing_stop_ids = stop_times_stop_ids - stops_stop_ids
+        for stop_id in missing_stop_ids:
+            self.errors.append(f"Error: stop_id {stop_id} in stop_times.txt does not exist in stops.txt")
+