# init(_:transformer:) Creates a select operation with a transformer. ``` init(_ columnSelection: ColumnSelection, transformer: T) where Estimator == TransformerToEstimatorAdaptor, T : Transformer, T.Input == UnwrappedInput? ``` ## Parameters `columnSelection` A selection of columns. `transformer` A transformer. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)