> ## Documentation Index
> Fetch the complete documentation index at: https://docs.encord.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Create an Ontology

<Note>We recommend using the [Encord platform to create Ontologies](/platform-documentation/Annotate/annotate-ontologies/annotate-create-ontologies). The platform allows you to visualize how different elements of the Ontology are related to each other.</Note>

Ontologies are used to label your data and define how concepts are related to each other.

The following script creates an Ontology called "My test Ontology" containing an object called `Cute Cat`, a radio button attribute for `colour`, and a checklist attribute for `features`. Examples for bounding boxes, rotatable bounding boxes, polygons, and bitmasks are provided.

The script outputs the hash of the Ontology. The hash is used for the creation of a Project.

Ensure you replace:

* `<file-path-to-ssh-private-key>` with the pull path to your private key.
* `My test Ontology` with the name of your Ontology.
* `Cute Cat` with the name of your Ontology class.
* As well as any other options relevant to your Ontology.

<CodeGroup>
  ```python Bounding Box theme={"dark"}
  from encord import EncordUserClient
  from encord.objects import Shape, Object, Option, OntologyStructure
  from encord.ontology import Ontology
  from encord.objects.attributes import RadioAttribute, ChecklistAttribute



  user_client = EncordUserClient.create_with_ssh_private_key(
      ssh_private_key_path='<file-path-to-ssh-private-key>'
      )

  ontology_structure = OntologyStructure()

  # Adding bounding box annotation
  ontology_structure.add_object("Cute Cat", shape=Shape.BOUNDING_BOX)


  # Adding a Classification of type radio button
  classification = ontology_structure.add_classification()
  cat_colour = classification.add_attribute(RadioAttribute, "colour", required=True)
  cat_colour.add_option("white")
  cat_colour.add_option("black")

  # Adding a Classification of type check box
  classification = ontology_structure.add_classification()
  cat_features = classification.add_attribute(ChecklistAttribute, "features")
  cat_features.add_option("soft")
  cat_features.add_option("fluffy")
  cat_features.add_option("friendly")

  cat_ontology = user_client.create_ontology(title="My test Ontology", structure=ontology_structure)

  # Prints the ontology hash
  print (cat_ontology.ontology_hash)

  ```

  ```python Rotatable Bounding Box theme={"dark"}
  from encord import EncordUserClient
  from encord.objects import Shape, Object, Option, OntologyStructure
  from encord.ontology import Ontology
  from encord.objects.attributes import RadioAttribute, ChecklistAttribute


  user_client = EncordUserClient.create_with_ssh_private_key(
      ssh_private_key_path='<file-path-to-ssh-private-key>'
      )

  ontology_structure = OntologyStructure()

  # Adding bounding box annotation
  ontology_structure.add_object("Cute Cat", shape=Shape.BOUNDING_BOX)


  # Adding a Classification of type radio button
  classification = ontology_structure.add_classification()
  cat_colour = classification.add_attribute(RadioAttribute, "colour", required=True)
  cat_colour.add_option("white")
  cat_colour.add_option("black")

  # Adding a Classification of type check box
  classification = ontology_structure.add_classification()
  cat_features = classification.add_attribute(ChecklistAttribute, "features")
  cat_features.add_option("soft")
  cat_features.add_option("fluffy")
  cat_features.add_option("friendly")

  cat_ontology = user_client.create_ontology(title="My test Ontology", structure=ontology_structure)

  # Prints the ontology hash
  print (cat_ontology.ontology_hash)

  ```

  ```python Polygon theme={"dark"}
  from encord import EncordUserClient
  from encord.objects import Shape, Object, Option, OntologyStructure
  from encord.ontology import Ontology
  from encord.objects.attributes import RadioAttribute, ChecklistAttribute


  user_client = EncordUserClient.create_with_ssh_private_key(
      ssh_private_key_path='<file-path-to-ssh-private-key>'
      )

  ontology_structure = OntologyStructure()

  # Adding bounding box annotation
  ontology_structure.add_object("Cute Cat", shape=Shape.POLYGON)


  # Adding a Classification of type radio button
  classification = ontology_structure.add_classification()
  cat_colour = classification.add_attribute(RadioAttribute, "colour", required=True)
  cat_colour.add_option("white")
  cat_colour.add_option("black")

  # Adding a Classification of type check box
  classification = ontology_structure.add_classification()
  cat_features = classification.add_attribute(ChecklistAttribute, "features")
  cat_features.add_option("soft")
  cat_features.add_option("fluffy")
  cat_features.add_option("friendly")

  cat_ontology = user_client.create_ontology(title="My test Ontology", structure=ontology_structure)

  # Prints the ontology hash
  print (cat_ontology.ontology_hash)

  ```

  ```python Bitmask theme={"dark"}
  from encord import EncordUserClient
  from encord.objects import Shape, Object, Option, OntologyStructure
  from encord.ontology import Ontology
  from encord.objects.attributes import RadioAttribute, ChecklistAttribute

  user_client = EncordUserClient.create_with_ssh_private_key(
      ssh_private_key_path='<file-path-to-ssh-private-key>'
      )

  ontology_structure = OntologyStructure()

  # Adding bounding box annotation
  ontology_structure.add_object("Cute Cat", shape=Shape.BITMASK)


  # Adding a Classification of type radio button
  classification = ontology_structure.add_classification()
  cat_colour = classification.add_attribute(RadioAttribute, "colour", required=True)
  cat_colour.add_option("white")
  cat_colour.add_option("black")

  # Adding a Classification of type check box
  classification = ontology_structure.add_classification()
  cat_features = classification.add_attribute(ChecklistAttribute, "features")
  cat_features.add_option("soft")
  cat_features.add_option("fluffy")
  cat_features.add_option("friendly")

  cat_ontology = user_client.create_ontology(title="My test Ontology", structure=ontology_structure)

  # Prints the ontology hash
  print (cat_ontology.ontology_hash)

  ```
</CodeGroup>