Multiple Tooltip Elements

I am looking for a way to display multiple elements within one tooltip. I did not find a way to do this in Altair directly. In vega-lite, I would do something like

"tooltip": [
          {"type": "quantitative", "aggregate": "sum", "field": "A"},
          {"type": "quantitative", "aggregate": "sum", "field": "B"}
          ],

and it would show the sum of A and the sum of B like so:

If Altair does not yet support this, I think this is a useful feature to be added in the future.

Regards, Immanuel

[jakevdp]

This is supported in the master branch, and will be included in the version 2.1 release. Just pass multiple field names to the tooltip encoding; e.g.

chart.encode(
    tooltip=['sum(A):Q', 'sum(B):Q']
)

[jakevdp]

It can also be done in version 2.0, but not as conveniently. You have to bypass the encode() method and modify the encoding directly without any shorthands; e.g.

chart = alt.Chart().encode(...) #... define the full chart + encodings first

# add multiple tooltips
chart.encoding.tooltip = [
          {"type": "quantitative", "aggregate": "sum", "field": "A"},
          {"type": "quantitative", "aggregate": "sum", "field": "B"}
]