pytac.extensions.base

class pystac.extensions.base.ExtensionManagementMixin

Abstract base class with methods for adding and removing extensions from STAC Objects. This class is generic over the type of object being extended (e.g. Item).

Concrete extension implementations should inherit from this class and either provide a concrete type or a bounded type variable.

See EOExtension for an example implementation.

classmethod add_to(obj: S) → None

Add the schema URI for this extension to the stac_extensions list for the given object, if it is not already present.

classmethod ensure_has_extension(obj: S, add_if_missing: bool = False) → None

Given a STACObject, checks if the object has this extension’s schema URI in its stac_extensions list. If add_if_missing is True, the schema URI will be added to the object.

Parameters:

• obj – The object to validate.

• add_if_missing – Whether to add the schema URI to the object if it is not already present. Defaults to False.

classmethod ensure_owner_has_extension(asset_or_link: pystac.Asset | AssetDefinition | pystac.Link, add_if_missing: bool = False) → None

Given an Asset, checks if the asset’s owner has this extension’s schema URI in its stac_extensions list. If add_if_missing is True, the schema URI will be added to the owner.

Parameters:

• asset – The asset whose owner should be validated.

• add_if_missing – Whether to add the schema URI to the owner if it is not already present. Defaults to False.

Raises:

STACError – If add_if_missing is True and asset.owner is None.

abstract classmethod get_schema_uri() → str

Gets the schema URI associated with this extension.

classmethod get_schema_uris() → list[str]

Gets a list of schema URIs associated with this extension.

classmethod has_extension(obj: S) → bool

Check if the given object implements this extension by checking pystac.STACObject.stac_extensions for this extension’s schema URI.

classmethod remove_from(obj: S) → None

Remove the schema URI for this extension from the pystac.STACObject.stac_extensions list for the given object.

classmethod validate_has_extension(obj: S, add_if_missing: bool = False) → None

DEPRECATED

Deprecated since version 1.9: Use ensure_has_extension() instead.

Given a STACObject, checks if the object has this extension’s schema URI in its stac_extensions list. If add_if_missing is True, the schema URI will be added to the object.

Parameters:

• obj – The object to validate.

• add_if_missing – Whether to add the schema URI to the object if it is not already present. Defaults to False.

classmethod validate_owner_has_extension(asset: pystac.Asset | AssetDefinition, add_if_missing: bool = False) → None

DEPRECATED

Deprecated since version 1.9: Use ensure_owner_has_extension() instead.

Given an Asset, checks if the asset’s owner has this extension’s schema URI in its stac_extensions list. If add_if_missing is True, the schema URI will be added to the owner.

Parameters:

• asset – The asset whose owner should be validated.

• add_if_missing – Whether to add the schema URI to the owner if it is not already present. Defaults to False.

Raises:

STACError – If add_if_missing is True and asset.owner is None.

class pystac.extensions.base.PropertiesExtension

Abstract base class for extending the properties of an Item to include properties defined by a STAC Extension.

This class should not be instantiated directly. Instead, create an extension-specific class that inherits from this class and instantiate that. See PropertiesEOExtension for an example.

additional_read_properties: Iterable[dict[str, Any]] | None = None

Additional read-only properties accessible from the extended object.

These are used when extending an Asset to give access to the properties of the owning Item. If a property exists in both additional_read_properties and properties, the value in additional_read_properties will take precedence.

properties: dict[str, Any]

The properties that this extension wraps.

The extension which implements PropertiesExtension can use _get_property and _set_property to get and set values on this instance. Note that _set_properties mutates the properties directly.

class pystac.extensions.base.SummariesExtension(collection: Collection)

Base class for extending the properties in pystac.Collection.summaries to include properties defined by a STAC Extension.

This class should generally not be instantiated directly. Instead, create an extension-specific class that inherits from this class and instantiate that. See SummariesEOExtension for an example.

summaries: Summaries

The summaries for the Collection being extended.