Datasets: [Feature] Keep the list of labels of a dataset as metadata

[jplu]

It would be useful to keep the list of the labels of a dataset as metadata. Either directly in the DatasetInfo or in the Arrow metadata.

[thomwolf]

Yes! I see mostly two options for this:

• a Feature approach like currently (but we might deprecate features)
• wrapping in a smart way the Dictionary arrays of Arrow: https://arrow.apache.org/docs/python/data.html?highlight=dictionary%20encode#dictionary-arrays

[jplu]

I would have a preference for the second bullet point.

[thomwolf]

This should be accessible now as a feature in dataset.info.features (and even have the mapping methods).

[jplu]

Perfect! Well done!!

[chiapas]

Hi,
I hope we could get a better documentation.
It took me more than 1 hour to found this way to get the label information.

[thomwolf]

Yes we are working on the doc right now, should be in the next release quite soon.