从文档中, Selection 对象说:

选择通常是通过使用selecttool在绘图中选择点来创建的,但也可以通过编程方式指定。

但我不知道如何用编程的方式设置一些选定的点。例如,如果我想通过单击某个按钮来更新选择。我可以更新元素 source.selected.indices ,但事件不会被触发,而且点也不会标记为选定

from bokeh.io import curdoc
from bokeh.models import ColumnDataSource
from bokeh.plotting import figure
from bokeh.layouts import column
from bokeh.models.tools import LassoSelectTool, TapTool
from bokeh.models.widgets.buttons import Button

source = ColumnDataSource(dict(
    x=[1, 2, 3, 4, 5, 6],
    y=[1, 2, 3, 4, 5, 6],
))

p = figure(
    plot_height=300,
    tools='',
)
p.circle( x='x', y='y', size=20, source=source)

lasso_select = LassoSelectTool(
    select_every_mousemove=False,
)
tap = TapTool()
tools = (lasso_select, tap)
p.add_tools(*tools)

def update_selection_programmatically():
    source.selected.update(indices=[4])           # the indices attribute is updated but the figure is not repainted, some event is not triggered.
                                                  # So the points are not marked as selected
bt = Button(
    label="Update Selection",
    button_type="success",
    width=50
)

bt.on_click(update_selection_programmatically)


def update_selection(attr, old, new):
    print('>> NEW SELECTION: {}'.format(new.indices))
    # new.indices = [0]       # this works fine here

source.on_change('selected', update_selection)

curdoc().add_root(column([p, bt]))

“索引”属性已更新,但图未重新绘制。