观察 ipywidget 滑块的方法不起作用

Question

我试图在滑块更改时调用函数，同时它随着动画的变化而变化。它不起作用，只有当我通过鼠标手动更改时它才会调用函数。这是我的代码：

import ipywidgets as widgets
    
play = widgets.Play(
    value=0,
    min=0,
    max=100,
    step=1,
    description="Press play",
    disabled=False)

slider = widgets.IntSlider(description="Slides")
   
def on_value_change(change):
    print(change['new'])
        
slider.observe(on_value_change, names='value') 
widgets.jslink((play, 'value'), (slider, 'value'))
widgets.HBox([play, slider])

请你帮我管理一下好吗？

Answer 1

从这个问题（https://github.com/jupyter-widgets/ipywidgets/issues/1775）看来，函数的输出需要在输出小部件中捕获。参见 Jason Grout 的例子：

import ipywidgets as widgets

out = widgets.Output()
def on_value_change(change):
    with out:
        print(change['new'])

slider = widgets.IntSlider(min=1, max=100, step=1, continuous_update=True)
play = widgets.Play(min=1, interval=2000)

slider.observe(on_value_change, 'value')
widgets.jslink((play, 'value'), (slider, 'value'))
widgets.VBox([play, slider, out])