# map_input

> **Function** in `langgraph`

📖 [View in docs](https://reference.langchain.com/python/langgraph/pregel/_io/map_input)

Map input chunk to a sequence of pending writes in the form (channel, value).

## Signature

```python
map_input(
    input_channels: str | Sequence[str],
    chunk: dict[str, Any] | Any | None,
) -> Iterator[tuple[str, Any]]
```

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[View source on GitHub](https://github.com/langchain-ai/langgraph/blob/1142ebf9213e3eb01b9d1e7223b9f6b30bf8da61/libs/langgraph/langgraph/pregel/_io.py#L81)