如何使用Bokeh中的下拉菜单在图形之间切换？

from bokeh.io import output_file, show
from bokeh.layouts import column
from bokeh.models import Select
from bokeh.plotting import figure

select = Select(title="选择图形", options=["图形1", "图形2", "图形3"])

plot1 = figure(title="图形1", ...)
plot2 = figure(title="图形2", ...)
plot3 = figure(title="图形3", ...)

def update_plot(attrname, old, new):
    if select.value == "图形1":
        layout.children[1] = plot1
    elif select.value == "图形2":
        layout.children[1] = plot2
    elif select.value == "图形3":
        layout.children[1] = plot3

select.on_change('value', update_plot)

layout = column(select, plot1)

show(layout)