# StringExampleMapper

> **Class** in `langchain_classic`

📖 [View in docs](https://reference.langchain.com/python/langchain-classic/smith/evaluation/string_run_evaluator/StringExampleMapper)

Map an example, or row in the dataset, to the inputs of an evaluation.

## Signature

```python
StringExampleMapper()
```

## Extends

- `Serializable`

## Properties

- `reference_key`
- `output_keys`

## Methods

- [`serialize_chat_messages()`](https://reference.langchain.com/python/langchain-classic/smith/evaluation/string_run_evaluator/StringExampleMapper/serialize_chat_messages)
- [`map()`](https://reference.langchain.com/python/langchain-classic/smith/evaluation/string_run_evaluator/StringExampleMapper/map)

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[View source on GitHub](https://github.com/langchain-ai/langchain/blob/9f232caa7a8fe1ca042a401942d5d90d54ceb1a6/libs/langchain/langchain_classic/smith/evaluation/string_run_evaluator.py#L225)