All properties in altair.Chart.configure_axisRight are Undefined

[domoritz]

In the docs at https://altair-viz.github.io/user_guide/generated/toplevel/altair.Chart.html?highlight=error%20bars#altair.Chart.configure_axisRight, all properties are defaulting to undefined.

[jakevdp]

Every property of every function in Altair defaults to Undefined. In Python, the default is normally None, but None translates to null in JSON, which has special meaning in Vega-Lite. So we created a new sentinel called "Undefined" to denote parameters that are not defined.

A bit confusing? Yes, but it seemed like the best way forward.

[jakevdp]

(an alternative would have been for every function signature to just be **kwargs, but then the parameters would not be explicitly listed in the call signature and would not tab complete)

[domoritz]

Thanks for the explanation.