isColumnGroup

Returns true if this column is a ColumnGroup, i.e., its kind is ColumnKind.Group.

This function has a contract: when it returns true, the compiler smart-casts this column to ColumnGroup<*>.

See also isFrameColumn, isValueColumn.

Use asColumnGroup to cast a column to ColumnGroup<*> without the check.

Examples

val name: AnyCol = df["name"]
if (name.isColumnGroup()) {
    // `name` is smart-cast to `ColumnGroup<*>` here
    name.columnNames() // returns [firstName, lastName]
}