# StringRunMapper

> **Class** in `langchain_classic`

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

Extract items to evaluate from the run object.

## Signature

```python
StringRunMapper()
```

## Extends

- `Serializable`

## Properties

- `output_keys`

## Methods

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

---

[View source on GitHub](https://github.com/langchain-ai/langchain/blob/185119f98e6286253a2326d7cf4f59592678023d/libs/langchain/langchain_classic/smith/evaluation/string_run_evaluator.py#L40)