# fiftyone.core.odm.mixins Mixins and helpers for dataset backing documents. Copyright 2017-2026, Voxel51, Inc.
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**Functions:** | [`get_default_fields`](#fiftyone.core.odm.mixins.get_default_fields)(cls[, include_private, ...]) | Gets the default fields present on all instances of the given [`DatasetMixin`](#fiftyone.core.odm.mixins.DatasetMixin) class. | |-----------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------| **Classes:** | [`DatasetMixin`](#fiftyone.core.odm.mixins.DatasetMixin)() | Mixin interface for [`fiftyone.core.odm.document.Document`](fiftyone.core.odm.document.md#fiftyone.core.odm.document.Document) subclasses that are backed by a dataset. | |----------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [`NoDatasetMixin`](#fiftyone.core.odm.mixins.NoDatasetMixin)() | Mixin for [`fiftyone.core.odm.document.SerializableDocument`](fiftyone.core.odm.document.md#fiftyone.core.odm.document.SerializableDocument) subtypes that are not backed by a dataset. | ### fiftyone.core.odm.mixins.get_default_fields(cls, include_private=False, use_db_fields=False) Gets the default fields present on all instances of the given [`DatasetMixin`](#fiftyone.core.odm.mixins.DatasetMixin) class. * **Parameters:** * **cls** – the [`DatasetMixin`](#fiftyone.core.odm.mixins.DatasetMixin) class * **include_private** (*False*) – whether to include fields starting with `_` * **use_db_fields** (*False*) – whether to return database fields rather than user-facing fields, when applicable * **Returns:** a tuple of field names ### *class* fiftyone.core.odm.mixins.DatasetMixin Bases: `object` Mixin interface for [`fiftyone.core.odm.document.Document`](fiftyone.core.odm.document.md#fiftyone.core.odm.document.Document) subclasses that are backed by a dataset. **Attributes:** | [`collection_name`](#fiftyone.core.odm.mixins.DatasetMixin.collection_name) | | |-------------------------------------------------------------------------------|----| | [`field_names`](#fiftyone.core.odm.mixins.DatasetMixin.field_names) | | **Methods:** | [`get_field`](#fiftyone.core.odm.mixins.DatasetMixin.get_field)(field_name) | | |-----------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------| | [`set_field`](#fiftyone.core.odm.mixins.DatasetMixin.set_field)(field_name, value[, create, ...]) | | | [`clear_field`](#fiftyone.core.odm.mixins.DatasetMixin.clear_field)(field_name) | | | [`get_field_schema`](#fiftyone.core.odm.mixins.DatasetMixin.get_field_schema)([ftype, embedded_doc_type, ...]) | Returns a schema dictionary describing the fields of this document. | | [`merge_field_schema`](#fiftyone.core.odm.mixins.DatasetMixin.merge_field_schema)(schema[, expand_schema, ...]) | Merges the field schema into this document. | | [`add_field`](#fiftyone.core.odm.mixins.DatasetMixin.add_field)(path, ftype[, embedded_doc_type, ...]) | Adds a new field or embedded field to the document, if necessary. | | [`add_implied_field`](#fiftyone.core.odm.mixins.DatasetMixin.add_implied_field)(path, value[, ...]) | Adds the field or embedded field to the document, if necessary, inferring the field type from the provided value. | #### *property* collection_name #### *property* field_names #### get_field(field_name) #### set_field(field_name, value, create=True, validate=True, dynamic=False, \_enforce_read_only=True) #### clear_field(field_name) #### *classmethod* get_field_schema(ftype=None, embedded_doc_type=None, subfield=None, read_only=None, info_keys=None, created_after=None, include_private=False, flat=False, unwind=True, mode=None) Returns a schema dictionary describing the fields of this document. If the document belongs to a dataset, the schema will apply to all documents in the collection. * **Parameters:** * **ftype** (*None*) – an optional field type or iterable of field types to which to restrict the returned schema. Must be subclass(es) of [`fiftyone.core.fields.Field`](fiftyone.core.fields.md#fiftyone.core.fields.Field) * **embedded_doc_type** (*None*) – an optional embedded document type or iterable of types to which to restrict the returned schema. Must be subclass(es) of [`fiftyone.core.odm.BaseEmbeddedDocument`](fiftyone.core.odm.md#fiftyone.core.odm.BaseEmbeddedDocument) * **subfield** (*None*) – an optional subfield type or iterable of subfield types to which to restrict the returned schema. Must be subclass(es) of [`fiftyone.core.fields.Field`](fiftyone.core.fields.md#fiftyone.core.fields.Field) * **read_only** (*None*) – whether to restrict to (True) or exclude (False) read-only fields. By default, all fields are included * **info_keys** (*None*) – an optional key or list of keys that must be in the field’s `info` dict * **created_after** (*None*) – an optional `datetime` specifying a minimum creation date * **include_private** (*False*) – whether to include fields that start with `_` in the returned schema * **flat** (*False*) – whether to return a flattened schema where all embedded document fields are included as top-level keys * **unwind** (*True*) – whether to traverse into list fields. Only applicable when `flat=True` * **mode** (*None*) – whether to apply the above constraints before and/or after flattening the schema. Only applicable when `flat=True`. Supported values are `("before", "after", "both")`. The default is `"after"` * **Returns:** a dict mapping field names to [`fiftyone.core.fields.Field`](fiftyone.core.fields.md#fiftyone.core.fields.Field) instances #### *classmethod* merge_field_schema(schema, expand_schema=True, recursive=True, validate=True, overwrite=False) Merges the field schema into this document. * **Parameters:** * **schema** – a dict mapping field names or `embedded.field.names` to [`fiftyone.core.fields.Field`](fiftyone.core.fields.md#fiftyone.core.fields.Field) instances * **expand_schema** (*True*) – whether to add new fields to the schema (True) or simply validate that fields already exist with consistent types (False) * **recursive** (*True*) – whether to recursively merge embedded document fields * **validate** (*True*) – whether to validate fields against existing fields at the same path * **overwrite** (*False*) – whether to overwrite the editable metadata of existing fields * **Returns:** True/False whether any new fields were added * **Raises:** **ValueError** – if a field in the schema is not compliant with an existing field of the same name or a new field is found but `expand_schema == False` #### *classmethod* add_field(path, ftype, embedded_doc_type=None, subfield=None, fields=None, description=None, info=None, read_only=False, expand_schema=True, recursive=True, validate=True, \*\*kwargs) Adds a new field or embedded field to the document, if necessary. * **Parameters:** * **path** – the field name or `embedded.field.name` * **ftype** – the field type to create. Must be a subclass of [`fiftyone.core.fields.Field`](fiftyone.core.fields.md#fiftyone.core.fields.Field) * **embedded_doc_type** (*None*) – the [`fiftyone.core.odm.BaseEmbeddedDocument`](fiftyone.core.odm.md#fiftyone.core.odm.BaseEmbeddedDocument) type of the field. Only applicable when `ftype` is [`fiftyone.core.fields.EmbeddedDocumentField`](fiftyone.core.fields.md#fiftyone.core.fields.EmbeddedDocumentField) * **subfield** (*None*) – the [`fiftyone.core.fields.Field`](fiftyone.core.fields.md#fiftyone.core.fields.Field) type of the contained field. Only applicable when `ftype` is [`fiftyone.core.fields.ListField`](fiftyone.core.fields.md#fiftyone.core.fields.ListField) or [`fiftyone.core.fields.DictField`](fiftyone.core.fields.md#fiftyone.core.fields.DictField) * **fields** (*None*) – a list of [`fiftyone.core.fields.Field`](fiftyone.core.fields.md#fiftyone.core.fields.Field) instances defining embedded document attributes. Only applicable when `ftype` is [`fiftyone.core.fields.EmbeddedDocumentField`](fiftyone.core.fields.md#fiftyone.core.fields.EmbeddedDocumentField) * **description** (*None*) – an optional description * **info** (*None*) – an optional info dict * **read_only** (*False*) – whether the field should be read-only * **expand_schema** (*True*) – whether to add new fields to the schema (True) or simply validate that the field already exists with a consistent type (False) * **recursive** (*True*) – whether to recursively add embedded document fields * **validate** (*True*) – whether to validate the field against an existing field at the same path * **Returns:** True/False whether one or more fields or embedded fields were added to the document or its children * **Raises:** **ValueError** – if a field in the schema is not compliant with an existing field of the same name #### *classmethod* add_implied_field(path, value, expand_schema=True, dynamic=False, recursive=True, validate=True) Adds the field or embedded field to the document, if necessary, inferring the field type from the provided value. * **Parameters:** * **path** – the field name or `embedded.field.name` * **value** – the field value * **expand_schema** (*True*) – whether to add new fields to the schema (True) or simply validate that the field already exists with a consistent type (False) * **dynamic** (*False*) – whether to declare dynamic embedded document fields * **recursive** (*True*) – whether to recursively add embedded document fields * **validate** (*True*) – whether to validate the field against an existing field at the same path * **Returns:** True/False whether one or more fields or embedded fields were added to the document or its children * **Raises:** **ValueError** – if a field in the schema is not compliant with an existing field of the same name ### *class* fiftyone.core.odm.mixins.NoDatasetMixin Bases: `object` Mixin for [`fiftyone.core.odm.document.SerializableDocument`](fiftyone.core.odm.document.md#fiftyone.core.odm.document.SerializableDocument) subtypes that are not backed by a dataset. **Attributes:** | [`field_names`](#fiftyone.core.odm.mixins.NoDatasetMixin.field_names) | | |-------------------------------------------------------------------------|----| | [`in_db`](#fiftyone.core.odm.mixins.NoDatasetMixin.in_db) | | **Methods:** | [`has_field`](#fiftyone.core.odm.mixins.NoDatasetMixin.has_field)(field_name) | | |-----------------------------------------------------------------------------------------------------|----| | [`get_field`](#fiftyone.core.odm.mixins.NoDatasetMixin.get_field)(field_name) | | | [`set_field`](#fiftyone.core.odm.mixins.NoDatasetMixin.set_field)(field_name, value[, create, ...]) | | | [`clear_field`](#fiftyone.core.odm.mixins.NoDatasetMixin.clear_field)(field_name) | | | [`to_dict`](#fiftyone.core.odm.mixins.NoDatasetMixin.to_dict)([extended]) | | | [`from_dict`](#fiftyone.core.odm.mixins.NoDatasetMixin.from_dict)(d[, extended]) | | | [`save`](#fiftyone.core.odm.mixins.NoDatasetMixin.save)() | | | [`reload`](#fiftyone.core.odm.mixins.NoDatasetMixin.reload)() | | | [`delete`](#fiftyone.core.odm.mixins.NoDatasetMixin.delete)() | | #### *property* field_names #### *property* in_db #### has_field(field_name) #### get_field(field_name) #### set_field(field_name, value, create=True, validate=True, dynamic=False) #### clear_field(field_name) #### to_dict(extended=False) #### *classmethod* from_dict(d, extended=False) #### save() #### reload() #### delete()