flatten
Returns DataFrame without column groupings under selected columns.
flatten [ { columns } ]
Columns will keep their original names after flattening. Potential column name clashes are resolved by adding minimal possible name prefix from ancestor columns.
Related operations: Group / ungroup / flatten columns
See column selectors for how to select the columns for this operation.
// name.firstName -> firstName
// name.lastName -> lastName
df.flatten { name }
// name.firstName -> firstName
// name.lastName -> lastName
df.flatten("name")
To remove all column groupings in DataFrame, invoke flatten without parameters:
df.flatten()
24 October 2025