# fix_filter_directive

> **Function** in `langchain_classic`

📖 [View in docs](https://reference.langchain.com/python/langchain-classic/chains/query_constructor/base/fix_filter_directive)

Fix invalid filter directive.

## Signature

```python
fix_filter_directive(
    filter: FilterDirective | None,
    *,
    allowed_comparators: Sequence[Comparator] | None = None,
    allowed_operators: Sequence[Operator] | None = None,
    allowed_attributes: Sequence[str] | None = None,
) -> FilterDirective | None
```

## Parameters

| Name | Type | Required | Description |
|------|------|----------|-------------|
| `filter` | `FilterDirective \| None` | Yes | Filter directive to fix. |
| `allowed_comparators` | `Sequence[Comparator] \| None` | No | allowed comparators. Defaults to all comparators. (default: `None`) |
| `allowed_operators` | `Sequence[Operator] \| None` | No | allowed operators. Defaults to all operators. (default: `None`) |
| `allowed_attributes` | `Sequence[str] \| None` | No | allowed attributes. Defaults to all attributes. (default: `None`) |

## Returns

`FilterDirective | None`

Fixed filter directive.

---

[View source on GitHub](https://github.com/langchain-ai/langchain/blob/02991cb4cf2063d51a07268edafb05fe53de1826/libs/langchain/langchain_classic/chains/query_constructor/base.py#L114)