DeferredDatasetHandle¶

class lsst.daf.butler.DeferredDatasetHandle(butler: LimitedButler, ref: DatasetRef, parameters: dict | None, storageClass: str | StorageClass | None = None)¶

Proxy class that provides deferred loading of datasets from a butler.

Attributes Summary

`dataId`	The full data ID associated with the dataset (`DataCoordinate`).
`storageClass`	Optional storage class override that can be applied on `get()`.

Methods Summary

get(*[, component, parameters, storageClass])

Retrieves the dataset pointed to by this handle

Attributes Documentation

dataId¶

The full data ID associated with the dataset (DataCoordinate).

Guaranteed to contain records.

storageClass: str | StorageClass | None = None¶: Optional storage class override that can be applied on get().

Methods Documentation

get(*, component: str | None = None, parameters: dict | None = None, storageClass: str | StorageClass | None = None) → Any¶

Retrieves the dataset pointed to by this handle

This handle may be used multiple times, possibly with different parameters.

Parameters:

componentstr or None: If the deferred object is a component dataset type, this parameter may specify the name of the component to use in the get operation.
parametersdict or None: The parameters argument will be passed to the butler get method. It defaults to None. If the value is not None, this dict will be merged with the parameters dict used to construct the DeferredDatasetHandle class.
storageClassStorageClass or str, optional: The storage class to be used to override the Python type returned by this method. By default the returned type matches the dataset type definition for this dataset or the storage class specified when this object was created. Specifying a read StorageClass can force a different type to be returned. This type must be compatible with the original type.

Returns: