fiftyone.core.singletons#

FiftyOne singleton implementations.

Copyright 2017-2025, Voxel51, Inc.

Classes:

DatasetSingleton(*args, **kwargs)

Singleton metaclass for fiftyone.core.dataset.Dataset.

DocumentSingleton

Singleton metaclass interface for fiftyone.core.document.Document subclasses.

SampleSingleton(*args, **kwargs)

Singleton metaclass for fiftyone.core.sample.Sample.

FrameSingleton(*args, **kwargs)

Singleton metaclass for fiftyone.core.frame.Frame.

class fiftyone.core.singletons.DatasetSingleton(*args, **kwargs)#

Bases: type

Singleton metaclass for fiftyone.core.dataset.Dataset.

Datasets are singletons keyed by the dataset’s name.

Note that new fiftyone.core.dataset.Dataset instances are always created if the _create == True.

Methods:

mro()

Return a type's method resolution order.

mro()#

Return a type’s method resolution order.

class fiftyone.core.singletons.DocumentSingleton#

Bases: type

Singleton metaclass interface for fiftyone.core.document.Document subclasses.

The methods declared by this interface are used by the fiftyone.core.document.Document class to manage all instances of a class that implements this type.

Methods:

mro()

Return a type's method resolution order.

mro()#

Return a type’s method resolution order.

class fiftyone.core.singletons.SampleSingleton(*args, **kwargs)#

Bases: DocumentSingleton

Singleton metaclass for fiftyone.core.sample.Sample.

This metaclass maintains a weakref dictionary of all in-memory fiftyone.core.sample.Sample instances keyed by [collection name][sample ID].

Methods:

mro()

Return a type's method resolution order.

mro()#

Return a type’s method resolution order.

class fiftyone.core.singletons.FrameSingleton(*args, **kwargs)#

Bases: DocumentSingleton

Singleton metaclass for fiftyone.core.frame.Frame.

This metaclass maintains a weakref dictionary of all in-memory fiftyone.core.frame.Frame instances keyed by [collection name][sample ID][frame number].

Methods:

mro()

Return a type's method resolution order.

mro()#

Return a type’s method resolution order.