# StringRunEvaluatorChain

> **Class** in `langchain_classic`

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

Evaluate Run and optional examples.

## Signature

```python
StringRunEvaluatorChain()
```

## Extends

- `Chain`
- `RunEvaluator`

## Properties

- `run_mapper`
- `example_mapper`
- `name`
- `string_evaluator`
- `input_keys`
- `output_keys`

## Methods

- [`evaluate_run()`](https://reference.langchain.com/python/langchain-classic/smith/evaluation/string_run_evaluator/StringRunEvaluatorChain/evaluate_run)
- [`aevaluate_run()`](https://reference.langchain.com/python/langchain-classic/smith/evaluation/string_run_evaluator/StringRunEvaluatorChain/aevaluate_run)
- [`from_run_and_data_type()`](https://reference.langchain.com/python/langchain-classic/smith/evaluation/string_run_evaluator/StringRunEvaluatorChain/from_run_and_data_type)

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[View source on GitHub](https://github.com/langchain-ai/langchain/blob/f0c5a28fa05adcda89aebcb449d897245ab21fa4/libs/langchain/langchain_classic/smith/evaluation/string_run_evaluator.py#L275)