routingOnGPKG.py

# Query the graph, calculates the wegiht, then read the data  the Dijstars Graph() class

graphQuery = """
-- Forwards, from start to end
	SELECT start_node as node1, end_node as node2, split_way_id,
                    CASE
                        WHEN json_extract(tags, '$.oneway') == '-1'  THEN 10000000000.0
                        ELSE length_m
                    END as cost
                    FROM osm_network_graph
                    WHERE json_extract(tags, '$.highway') IN {0}

	UNION
-- Backwards, from end to start
	SELECT end_node as node1, start_node as node2, split_way_id, 
		CASE
			WHEN json_extract(tags, '$.oneway') == 'yes' THEN 10000000000.0
			ELSE length_m
		END as cost
	FROM osm_network_graph
        WHERE json_extract(tags, '$.highway') IN {0};""".format(str(tuple(Vehicle)))
cursor.execute(graphQuery)

# Define Graph() Object

osmGraph = Graph()
[osmGraph.add_edge(item[0],item[1],{'edge_id':item[2],'cost':item[3]}) for item in cursor.fetchall()]

# Define a function that will be applied to the graph to return the cost of each edge
cost_func = cost_func = lambda u, v, e, prev_e: e['cost']

# Solve from Starting Node To End Node
PointA = 3415159798 # National Stadium - Washington, DC
PointB = 2179757650 # John F. Kennedy Center, Washington DC

try:
    path = find_path(graph=osmGraph, s=PointA,d=PointB,cost_func=cost_func)

    # Collect Edge Ids

    edges = [edge['edge_id'] for edge in path.edges]

    # Create a GeoPackageView Of Route
    routeSeqence = ''.join(['WHEN osm.split_way_id={} THEN {} '.format(edges[i],i) for i in range(len(edges))])

    try:
        createView = """CREATE VIEW route AS
                                SELECT CASE {0} END AS route_sequence, osm.*
                                FROM osm_network_graph osm
                                WHERE osm.split_way_id IN {1}""".format(routeSeqence,str(tuple(edges)))

        insertToGpkgContents = """INSERT INTO gpkg_contents (table_name, identifier, data_type, srs_id)
                                            VALUES('route','route','features',4326)"""

        insertToGpkgGeometryColumn ="""INSERT INTO gpkg_geometry_columns (table_name, column_name, geometry_type_name, srs_id, z, m)
                                            VALUES ('route', 'geom', 'LINESTRING', 4326, 0, 0)"""

        cursor.execute(createView)
        cursor.execute(insertToGpkgGeometryColumn)
        cursor.execute(insertToGpkgContents)
        databaseConnection.commit()
    except sqlite3.OperationalError:
        print('View Currently Exists')
    databaseConnection.close()



    # Execpt error is no path is found
except NoPathError:
    print('No Path Found')