df-research/dataframe/docs/StardustDocs/topics/xs.md

Return cross-section from the DataFrame.

Filters DataFrame by matching key values with key columns and removes key columns.

xs(vararg keyValues: Any?)
     [ { keyColumns } ]

When keyColumns are not specified, it takes first n columns in dfs order (looking inside ColumnGroup), where n is a number of given keyValues.

df.xs("Charlie", "Chaplin")

df.xs("Moscow", true) { city and isHappy }