I have list of locations in Gothenburg, Sweden for which I calculated a route matrix (distance shortest path from each location to all others, only in one direction). Now for a demonstration, I wish to create a shapefile of the entire set of routes, somehow I don’t get how to combine all routes to a graph.

I am aware that I am supposed to use GeoPackage instead, but until now I always failed to open GeoPackage files in ArcMap. Also the problem creating the graph would remain the same…

I would be very grateful for your assistance.

My code looks as follows:

import osmnx as ox
import geopandas as gpd
import pandas as pd


city = 'Göteborg, Sweden'
graph = ox. graph_from_place(city, network_type='walk')
# locations dataframe from excel
filename = 'places.xlsx'
places = pd.read_excel(filename)

# for each place --> closest node in graph
place_nodes = []
for i in range(len(places)):
    i_lat = places["Lat"].loc[i]
    i_long = places["Long"].loc[i]
    i_node = ox.nearest_nodes(graph, i_long, i_lat, return_dist=False)
    place_nodes.append(i_node)

all_nodes = set()

for i_from in range(len(place_nodes)):
    # only one direction
    for i_to in range(i_from+1, len(place_nodes)):
        # calc route
        dist_nodes = ox.shortest_path(graph, place_nodes[i_from], place_nodes[i_to], weight='length')
        print(dist_nodes)
        # list of route edges
        dist_edges = ox.utils_graph.route_to_gdf(graph, dist_nodes)
        print (dist_edges)
        # route length
        length = dist_edges["length"].sum() / 1000
        print("From", places["Place"].loc[i_from], "to", places["Place"].loc[i_to], "it's", length, "km.")
        # set of all node ids without duplicates
        all_nodes.update(set(dist_nodes) - all_nodes)
        # first run
        if i_from + i_to == 1:
            all_edges = dist_edges
        # all other runs_ gdf with all edges in routes
        else:
            all_edges = gpd.GeoDataFrame(pd.concat([all_edges, dist_edges], ignore_index=True))

nodes, edges = ox.graph_to_gdfs(graph)
# gdf with all nodes in routes
route_nodes = nodes.loc[all_nodes]
all_edges.set_index('osmid', inplace=True)
# create graph, then shapefile
shapegraph = ox.utils_graph.graph_from_gdfs(route_nodes, all_edges, graph_attrs=None)
ox.io.save_graph_shapefile(shapegraph, filepath=None, encoding='utf-8', directed=False)

I believe that reason for the error is hidden in the concatenation, as adding

.drop_duplicates()

to that line also throws an error…

Like I mentioned before, I am extremely grateful for any hint to what I did wrong.