Get a line like [<matplotlib.lines.Line2D at 0x7f610447e140>] when trying to plot, and an 'empty' plot which seems to have a toolbar of button, but no content. Failed to fetch ipywidgets through the ...

a ``Slider`` to control a single float. See :doc:`/gallery/widgets/slider_snap_demo` for an example of having the ``Slider`` snap to discrete values.