Output widget does not work in notebook 4.x

[jdemeyer]

Doing exactly what the documentation of Output? says does not actually work. When creating a notebook cell with the code

import ipywidgets as widgets
from IPython.display import display
out = widgets.Output()
display(out)

print('prints to output area')

with out:
    print('prints to output widget')

the string prints to output widget is displayed normally and ''not'' in the Output widget.

[jasongrout]

Output widget should work if you have one of the recent ipywidgets/widgetsnbextension beta versions, and you are either on notebook master or you're using jupyter/notebook#2022 on notebook 4.3.x.

Or if you're on jlab.

[jasongrout]

Output widget is I think completely broken in ipywidgets on released versions of notebook 4.x.

[jasongrout]

To resolve this, we should either:

(a) decide that we only need to support notebook 5.0, and have 5.0 released before ipywidgets 6.0.

or

(b) release notebook 4.4 with my changes at jupyter/notebook#2022 to enable the output widget

@SylvainCorlay - this impacts our release timeline for 6.0.

[SylvainCorlay]

I would like to get jupyter/notebook#2087 fixed in notebook 5.0.

[jasongrout]

We've now merged the necessary changes and plan to release Notebook 4.4 supporting the output widget.