我正试图从Bokeh中的GraphRender对象中使用box select来获取所选节点的索引，以便创建链接的数据表。(我希望能够获得所选节点的索引(
这个问题有点类似于：JavaScript回调以获得Bokeh中的选定字形索引，但我无法使用他们提出的解决方案来解决这个问题。
完整的代码如下，我试图用自定义JS回调来解决它，但我无法做到
非常感谢您的帮助。提前感谢！
(注意：这是我的第一个问题，所以如果需要进一步的信息，请告诉我。(
import pandas as pd
import numpy as np
from bokeh.layouts import row, widgetbox, column
from bokeh.models import ColumnDataSource, CustomJS, StaticLayoutProvider, Oval, Circle
from bokeh.models import HoverTool, TapTool, BoxSelectTool, GraphRenderer
from bokeh.models.widgets import RangeSlider, Button, DataTable, TableColumn, NumberFormatter
from bokeh.io import curdoc, show, output_notebook
from bokeh.plotting import figure
import networkx as nx
from bokeh.io import show, output_file
from bokeh.plotting import figure
from bokeh.models.graphs import from_networkx, NodesAndLinkedEdges, EdgesAndLinkedNodes, NodesOnly
# Import / instantiate networkx graph
G = nx.Graph()
G.add_edge('a', 'b', weight=0.6)
G.add_edge('a', 'c', weight=0.2)
G.add_edge('c', 'd', weight=0.1)
G.add_edge('c', 'e', weight=0.7)
G.add_edge('c', 'f', weight=0.9)
G.add_edge('a', 'd', weight=0.3)
# Node Characteristics
node_name = list(G.nodes())
positions = nx.spring_layout(G)
node_size = [k*4 for k in range(len(G.nodes()))]
nx.set_node_attributes(G, node_size, 'node_size')
visual_attributes=ColumnDataSource(
pd.DataFrame.from_dict({k:v for k,v in G.nodes(data=True)},orient='index'))
# Edge characteristics
start_edge = [start_edge for (start_edge, end_edge) in G.edges()]
end_edge = [end_edge for (start_edge, end_edge) in G.edges()]
weight = list(nx.get_edge_attributes(G,'weight').values())
edge_df = pd.DataFrame({'source':start_edge, 'target':end_edge, 'weight':weight})
# Create full graph from edgelist
G = nx.from_pandas_edgelist(edge_df,edge_attr=True)
# Convert full graph to Bokeh network for node coordinates and instantiate Bokeh graph object
G_source = from_networkx(G, nx.spring_layout, scale=2, center=(0,0))
graph = GraphRenderer()
# Update loop where the magic happens
def update():
selected_df = edge_df[(edge_df['weight'] >= slider.value[0]) & (edge_df['weight'] <= slider.value[1])]
sub_G = nx.from_pandas_edgelist(selected_df,edge_attr=True)
sub_graph = from_networkx(sub_G, nx.spring_layout, scale=2, center=(0,0))
graph.edge_renderer.data_source.data = sub_graph.edge_renderer.data_source.data
graph.node_renderer.data_source.data = G_source.node_renderer.data_source.data
graph.node_renderer.data_source.add(node_size,'node_size')
def selected_points(attr,old,new):
selected_idx = graph.node_renderer.selected.indices #does not work
print(selected_idx)
# Slider which changes values to update the graph
slider = RangeSlider(title="Weights", start=0, end=1, value=(0.25, 0.75), step=0.10)
slider.on_change('value', lambda attr, old, new: update())
# Plot object which is updated
plot = figure(title="Meetup Network Analysis", x_range=(-1.1,1.1), y_range=(-1.1,1.1),
tools = "pan,wheel_zoom,box_select,reset,box_zoom,crosshair", plot_width=800, plot_height=800)
# Assign layout for nodes, render graph, and add hover tool
graph.layout_provider = StaticLayoutProvider(graph_layout=positions)
graph.node_renderer.glyph = Circle(size='node_size')
graph.selection_policy = NodesOnly()
plot.renderers.append(graph)
plot.tools.append(HoverTool(tooltips=[('Name', '@index')]))
# Set layout
layout = column(slider,plot)
# does not work
#graph.node_renderer.data_source.on_change("selected", selected_points)
# Create Bokeh server object
curdoc().add_root(layout)
update()
不要将侦听器放在graph.node_renderer.data_source.on_change上，而是使用以下内容：
graph.node_renderer.data_source.selected.on_change("indices", selected_points)
这将触发服务器端响应。
弘毅