# PairwiseStringDistanceEvalChain

> **Class** in `langchain_classic`

📖 [View in docs](https://reference.langchain.com/python/langchain-classic/evaluation/string_distance/base/PairwiseStringDistanceEvalChain)

Compute string edit distances between two predictions.

## Signature

```python
PairwiseStringDistanceEvalChain()
```

## Extends

- `PairwiseStringEvaluator`
- `_RapidFuzzChainMixin`

## Properties

- `input_keys`
- `evaluation_name`

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[View source on GitHub](https://github.com/langchain-ai/langchain/blob/9f232caa7a8fe1ca042a401942d5d90d54ceb1a6/libs/langchain/langchain_classic/evaluation/string_distance/base.py#L325)