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)
            # 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)