How to perform an onclick action on button click in python bokeh?

Question

I'm new to bokeh and I have aquery regarding button onclick event, the code is provided below:

    x = widgetbox(button)
    show(x)
    fruits = ['Answered', 'Unanswered','Total']
    top1=[1,2,3]
    def callback():
        p = figure(x_range=fruits, plot_height=250, title="sophia bot")
        p.vbar(x=fruits, top=top1, width=0.9)
        p.xgrid.grid_line_color = None
        p.y_range.start = 0
        output_file("abc.html")
        show(p)
    button_one = Button(label="Start", disabled=True, callback=callback)
    show(button_one)

but this isnt performing the action, the following code when used alone, does plot the graph, i want the graph to be shown alongisde when i clicke the button.

    fruits = ['Answered', 'Unanswered','Total']
    top1=[1,2,3]
    p = figure(x_range=fruits, plot_height=250, title="sophia bot")
    p.vbar(x=fruits, top=top1, width=0.9)
    p.xgrid.grid_line_color = None
    p.y_range.start = 0
    output_file("abc.html")
    show(p)

Thanks

Solution

You must assign the callback to the button like this:

from bokeh.models import Button
from bokeh.io import curdoc

bt = Button(label='Click me')

def change_click():
    print('I was clicked')

bt.on_click(change_click)

curdoc().add_root(bt)

Launch this with bokeh serve --show example.py.

Note: Also take a look at my question where I talk about dynamic layout