python - 暂停Jupyter Notebook小部件，等待用户输入

Question

我和TheInterestedOne询问here有同样的问题。

我需要为用户创建两个按钮，并建议用户单击循环中两个按钮之一；因此，只有在用户选择之后，循环的下一次迭代才会发生。

我读了this source，但是不能使它适用于按钮。我不明白，在使用按钮的情况下，widget属性是如何变化的。

from functools import wraps
def yield_for_change(widget, attribute):
    def f(iterator):
        @wraps(iterator)
        def inner():
            i = iterator()
            def next_i(change):
                try:
                    i.send(change.new)
                except StopIteration as e:
                    widget.unobserve(next_i, attribute)
            widget.observe(next_i, attribute) //**button.on_click(on_button_clicked) 
                                                                may be?**
            # start the generator
            next(i)
        return inner
    return f


from ipywidgets import Button
button=Button()


def on_button_clicked():
    print("Button clicked.")


@yield_for_change(button, 'value')
def f():
    for i in range(10):
        print('did work %s'%i)
        x = yield
        button.on_click(on_button_clicked)

Answer 1

此版本使用awaitio并针对按钮进行了修改。

from ipywidgets import Button
import asyncio

def wait_for_change(widget):
    future = asyncio.Future()
    def getvalue(change):
        future.set_result(change.description)
        widget.on_click(getvalue, remove=True) 
        # we need to free up the binding to getvalue to avoid an InvalidState error
        # buttons don't support unobserve
        # so use `remove=True` 
    widget.on_click(getvalue)
    return future

button = Button(description="wow")

list_to_tag = ["one", "two", "three", "four"]

async def f():
    for i in list_to_tag:
        print("going to tag {}".format(i))
        x = await wait_for_change(button)
        print("tagged {} with {}".format(i, x))
        print()

asyncio.create_task(f())
button