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# fiftyone.core.ontology_validation

Validation for [`fiftyone.core.ontology`](fiftyone.core.ontology.md#module-fiftyone.core.ontology) SDK classes.

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**Functions:**

| [`validate_annotation_ontology`](#fiftyone.core.ontology_validation.validate_annotation_ontology)(ontology)   | Validates an `AnnotationOntology`.   |
|---------------------------------------------------------------------------------------------------------------|--------------------------------------|
| [`validate_taxonomy`](#fiftyone.core.ontology_validation.validate_taxonomy)(taxonomy)                         | Validates a `Taxonomy`.              |

### fiftyone.core.ontology_validation.validate_annotation_ontology(ontology: [AnnotationOntology](fiftyone.core.ontology.md#fiftyone.core.ontology.AnnotationOntology)) → None

Validates an `AnnotationOntology`.

Aggregates all ontology-level failures into a single error.
`When` operators are validated on construction.

* **Parameters:**
  **ontology** – the ontology to validate
* **Raises:**
  **ValueError** – if any rule fails

### fiftyone.core.ontology_validation.validate_taxonomy(taxonomy: [Taxonomy](fiftyone.core.ontology.md#fiftyone.core.ontology.Taxonomy)) → None

Validates a `Taxonomy`.

Aggregates all taxonomy-level failures into a single error.

* **Parameters:**
  **taxonomy** – the taxonomy to validate
* **Raises:**
  **ValueError** – if any rule fails