Handling location change on draggable Markers

[namKolorfuL]

Hi, I created a script for an interactive map to find shortest path between 2 locations based on https://ipyleaflet.readthedocs.io/en/latest/usage.html?highlight=observe and https://git.io/J6y6O This is how I handle change in marker position:

from_marker = Marker(location=current_pos, draggable=True)
to_marker = Marker(location=current_pos, icon=to_marker_style, draggable=True)

path_layer_list = []

def handle_change_location(event, marker):
    event_owner = event['owner']
    event_owner.nearest_node = ox.get_nearest_node(graph, event_owner.location)
    marker.neares_node = ox.get_nearest_node(graph, marker.location)
    
    shortest_path = nx.dijkstra_path(graph, event_owner.nearest_node, marker.neares_node, 
                                     weight='length')
    
    if len(path_layer_list) == 1:
        m.remove_layer(path_layer_list[0])
        path_layer_list.pop()
    
    shortest_path_points = nodes.loc[shortest_path]
    print(shortest_path_points)   # PRINT SHORTEST PATH
    path = gpd.GeoDataFrame([LineString(shortest_path_points.geometry.values)], columns=['geometry'])
    path.to_file('dataframe.shp')
    path_layer = GeoData(geo_dataframe=path, style={'color':'blue', 'weight':2})
    m.add_layer(path_layer)
    path_layer_list.append(path_layer)

from_marker.observe(lambda event: handle_change_location(event, to_marker), 'location')
to_marker.observe(lambda event: handle_change_location(event, from_marker), 'location')

Everything looks good but I need to access the shortest_path_points for my navigation application. I can't access or print any value in the handle_change_location function. Any idea on how it should be done? Thanks!