LineString 유형의 개체는 JSON 직렬화가 불가능합니다. (Object of type LineString is not JSON serializable)

문제 설명

LineString 유형의 개체는 JSON 직렬화가 불가능합니다. (Object of type LineString is not JSON serializable)

folium.GeoJSON을 사용할 때 이 오류를 어떻게 알 수 있습니까? gdf는 지리 데이터 프레임입니다. gdf.to_json()도 시도했지만 작동하지 않습니다. 저는 postgresql 데이터베이스(postgis)로 장고 환경에서 일하고 있습니다. geodataframe gdf는 geojson 파일에서 변환되었습니다. 이제 "'NoneType' 개체가 첨자할 수 없습니다.'라는 오류가 발생했습니다.

 def retrieve_data_from_postgres(network_id,
                          set_initial_crs=4326,
                          zone_radius=15,
                          intersection_radius_percentage=0.8,
                          distance_offset_percentage=0.8,
                          line_color='orange',
                          link_side='right',

                          ):
    initial_crs = "EPSG:{}".format(set_initial_crs)
    initial_crs = CRS(initial_crs)
    CRS84 = "EPSG:4326"
    default_crs = "EPSG:3857"

    edges = Edge.objects.filter(network_id=network_id)
    edges = serialize('geojson', edges,
        fields=('id', 'param1', 'param2', 'param3', 'speed', 'length',
        'lanes','geometry', 'name', 'source', 'target','network', 'road_type'))

    edges = json.loads(edges)
    edges_gdf = gpd.GeoDataFrame.from_features(edges['features']) # Convert a geojson as geodataframe

    nodes = Node.objects.filter(network_id=network_id).values()
    nodes_df = pd.DataFrame(nodes)
    nodes_df['location'] = nodes_df['location'].apply(geometry.Point)
    nodes_gdf = gpd.GeoDataFrame(nodes_df, geometry=nodes_df['location'])

   edges_gdf.set_crs(initial_crs, inplace=True)
   nodes_gdf.set_crs(initial_crs, inplace=True)
   nodes_gdf.to_crs(CRS84, inplace=True)
   zone_radius = zone_radius
   intersection_radius = intersection_radius_percentage * zone_radius
   distance_offset = distance_offset_percentage * zone_radius
   tiles_layer = 'OpenStreetMap'


    G = nx.from_pandas_edgelist(edges_gdf, 'source', 'target',
            ['speed', 'length', 'lanes', 'name', 'geometry'],
             create_using=nx.MultiDiGraph())

    # Add oneway column (it is a boolean column)
    for u, v, d in G.edges(keys=False, data=True):
        if G.has_edge(v, u):
            G.edges[u, v, 0]['oneway'] = False
        else:
            G.edges[u, v, 0]['oneway'] = True

    df_graph_to_pandas = nx.to_pandas_edgelist(G, source='source', target='target')
    gdf = gpd.GeoDataFrame(df_graph_to_pandas, geometry='geometry')
    gdf.set_crs(CRS84, inplace=True)

    # On convertit en metre (m) avant d'appliquer le décalage afin
    # d'uniformiser car parallel_offset se calcule en (m)
    gdf.to_crs(crs=default_crs, inplace=True)

    # Define parallel offset Geoserie
    # geometry to offset and column it depends on
    col_list = ['geometry', 'oneway']
    gdf['_offset_geometry_'] = gdf[col_list].apply(
        lambda x: x['geometry'].parallel_offset(
            distance_offset, link_side) if not x['oneway']
        else x['geometry'].parallel_offset(0, link_side),
        axis=1)

    # Drop old geometry and replace it by _offset_geometry_
    gdf.drop('geometry', axis=1, inplace=True)
    gdf.set_geometry('_offset_geometry_', inplace=True)
    gdf.set_crs(default_crs, inplace=True)

    # Converting back in 4326 before ploting
    gdf.to_crs(crs=CRS84, inplace=True)

    latitudes = list(nodes_gdf['geometry'].y)
    longitudes = list(nodes_gdf['geometry'].x)

    # Initialize the map
    m = folium.Map(location=[latitudes[0], longitudes[0]],
                   max_zoom=18, prefer_canvas=True, tiles=tiles_layer)

    print(gdf.columns)
    layer=folium.GeoJson(
        gdf,
        tooltip=folium.GeoJsonTooltip(fields=['oneway','lanes',
        'length','speed','name'],localize=True),
        style_function=lambda x: {
            'color': line_color
        }).add_to(m)

    # Bounding box the map such that the network is entirely center and visible
    m.fit_bounds(layer.get_bounds())

    # Adding the nodes points
    for lat, long in list(zip(latitudes, longitudes)):
        folium.Circle(location=[lat, long], color='cyan', fill=True,
            fill_opacity=1,radius=intersection_radius).add_to(m)

    m.save('templates/visualization.html')

참조 솔루션

방법 1:

Your GeoDataFrame gdf contains a LineString geometry in another column apart from the active geometry. GeoPandas is currently (as of 0.9.0) not able to convert those to JSON (see this bug report https://github.com/geopandas/geopandas/issues/1906). You need to drop the affected column before passing it to folium or convert it to something else yourself.

(by aba2s、martinfleis)

참조 문서

1. Object of type LineString is not JSON serializable (CC BY‑SA 2.5/3.0/4.0)