widgets always coerce the value to a default. this sometimes leads to unwanted behaviour in user input forms when the user selects nothing but the widget always returns a default value.
i.e.
import ipywidgets as widgets
widgets.IntText(value=None).value
# 0
in traitlets you can allow_none
for a given value… is there a way to do this for widgets (e.g. widgets.IntText)