fiftyone.core.odm.document¶

Base classes for documents that back dataset contents.

Classes:

 BaseDocument Base class for documents that are written to the database in their own collections. Document(*args, **values) Base class for documents that are stored in a MongoDB collection. DynamicDocument(*args, **values) Base class for dynamic documents that are stored in a MongoDB collection. MongoEngineBaseDocument Mixin for all mongoengine:mongoengine.base.BaseDocument subclasses that implements the SerializableDocument interface. SerializableDocument Mixin for documents that can be serialized in BSON or JSON format.
class fiftyone.core.odm.document.SerializableDocument

Bases: object

Mixin for documents that can be serialized in BSON or JSON format.

Methods:

 clear_field(field_name) Clears the field from the document. Returns a deep copy of the document. fancy_repr([class_name, select_fields, …]) Generates a customizable string representation of the document. from_dict(d[, extended]) Loads the document from a BSON/JSON dictionary. Loads the document from a JSON string. get_field(field_name) Gets the field of the document. has_field(field_name) Determines whether the document has a field of the given name. set_field(field_name, value[, create]) Sets the value of a field of the document. to_dict([extended]) Serializes this document to a BSON/JSON dictionary. to_json([pretty_print]) Serializes the document to a JSON string.
fancy_repr(class_name=None, select_fields=None, exclude_fields=None, **kwargs)

Generates a customizable string representation of the document.

Parameters
• class_name (None) – optional class name to use

• select_fields (None) – iterable of field names to restrict to

• exclude_fields (None) – iterable of field names to exclude

• **kwargs – additional key-value pairs to include in the string representation

Returns

a string representation of the document

has_field(field_name)

Determines whether the document has a field of the given name.

Parameters

field_name – the field name

Returns

True/False

get_field(field_name)

Gets the field of the document.

Parameters

field_name – the field name

Returns

the field value

Raises

AttributeError – if the field does not exist

set_field(field_name, value, create=False)

Sets the value of a field of the document.

Parameters
• field_name – the field name

• value – the field value

• create (False) – whether to create the field if it does not exist

Raises

ValueError – if field_name is not an allowed field name or does not exist and create == False

clear_field(field_name)

Clears the field from the document.

Parameters

field_name – the field name

Raises

ValueError – if the field does not exist

copy()

Returns a deep copy of the document.

Returns
to_dict(extended=False)

Serializes this document to a BSON/JSON dictionary.

Parameters

extended (False) – whether to serialize extended JSON constructs such as ObjectIDs, Binary, etc. into JSON format

Returns

a dict

classmethod from_dict(d, extended=False)

Loads the document from a BSON/JSON dictionary.

Parameters
• d – a dictionary

• extended (False) – whether the input dictionary may contain serialized extended JSON constructs

Returns
to_json(pretty_print=False)

Serializes the document to a JSON string.

Parameters

pretty_print (False) – whether to render the JSON in human readable format with newlines and indentations

Returns

a JSON string

classmethod from_json(s)

Loads the document from a JSON string.

Returns
class fiftyone.core.odm.document.MongoEngineBaseDocument

Mixin for all mongoengine:mongoengine.base.BaseDocument subclasses that implements the SerializableDocument interface.

Methods:

 clear_field(field_name) Clears the field from the document. Returns a deep copy of the document. fancy_repr([class_name, select_fields, …]) Generates a customizable string representation of the document. field_to_mongo(field_name) field_to_python(field_name, value) from_dict(d[, extended]) Loads the document from a BSON/JSON dictionary. Loads the document from a JSON string. get_field(field_name) Gets the field of the document. has_field(field_name) Determines whether the document has a field of the given name. set_field(field_name, value[, create]) Sets the value of a field of the document. to_dict([extended]) Serializes this document to a BSON/JSON dictionary. to_json([pretty_print]) Serializes the document to a JSON string.
has_field(field_name)

Determines whether the document has a field of the given name.

Parameters

field_name – the field name

Returns

True/False

get_field(field_name)

Gets the field of the document.

Parameters

field_name – the field name

Returns

the field value

Raises

AttributeError – if the field does not exist

set_field(field_name, value, create=False)

Sets the value of a field of the document.

Parameters
• field_name – the field name

• value – the field value

• create (False) – whether to create the field if it does not exist

Raises

ValueError – if field_name is not an allowed field name or does not exist and create == False

clear_field(field_name)

Clears the field from the document.

Parameters

field_name – the field name

Raises

ValueError – if the field does not exist

field_to_mongo(field_name)
field_to_python(field_name, value)
to_dict(extended=False)

Serializes this document to a BSON/JSON dictionary.

Parameters

extended (False) – whether to serialize extended JSON constructs such as ObjectIDs, Binary, etc. into JSON format

Returns

a dict

classmethod from_dict(d, extended=False)

Loads the document from a BSON/JSON dictionary.

Parameters
• d – a dictionary

• extended (False) – whether the input dictionary may contain serialized extended JSON constructs

Returns
copy()

Returns a deep copy of the document.

Returns
fancy_repr(class_name=None, select_fields=None, exclude_fields=None, **kwargs)

Generates a customizable string representation of the document.

Parameters
• class_name (None) – optional class name to use

• select_fields (None) – iterable of field names to restrict to

• exclude_fields (None) – iterable of field names to exclude

• **kwargs – additional key-value pairs to include in the string representation

Returns

a string representation of the document

classmethod from_json(s)

Loads the document from a JSON string.

Returns
to_json(pretty_print=False)

Serializes the document to a JSON string.

Parameters

pretty_print (False) – whether to render the JSON in human readable format with newlines and indentations

Returns

a JSON string

class fiftyone.core.odm.document.BaseDocument

Base class for documents that are written to the database in their own collections.

The ID of a document is automatically populated when it is added to the database, and the ID of a document is None if it has not been added to the database.

id

the ID of the document, or None if it has not been added to the database

Methods:

 clear_field(field_name) Clears the field from the document. Returns a deep copy of the document. fancy_repr([class_name, select_fields, …]) Generates a customizable string representation of the document. field_to_mongo(field_name) field_to_python(field_name, value) from_dict(d[, extended]) Loads the document from a BSON/JSON dictionary. Loads the document from a JSON string. get_field(field_name) Gets the field of the document. has_field(field_name) Determines whether the document has a field of the given name. set_field(field_name, value[, create]) Sets the value of a field of the document. to_dict([extended]) Serializes this document to a BSON/JSON dictionary. to_json([pretty_print]) Serializes the document to a JSON string.

Attributes:

 in_db Whether the document has been inserted into the database.
property in_db

Whether the document has been inserted into the database.

clear_field(field_name)

Clears the field from the document.

Parameters

field_name – the field name

Raises

ValueError – if the field does not exist

copy()

Returns a deep copy of the document.

Returns
fancy_repr(class_name=None, select_fields=None, exclude_fields=None, **kwargs)

Generates a customizable string representation of the document.

Parameters
• class_name (None) – optional class name to use

• select_fields (None) – iterable of field names to restrict to

• exclude_fields (None) – iterable of field names to exclude

• **kwargs – additional key-value pairs to include in the string representation

Returns

a string representation of the document

field_to_mongo(field_name)
field_to_python(field_name, value)
classmethod from_dict(d, extended=False)

Loads the document from a BSON/JSON dictionary.

Parameters
• d – a dictionary

• extended (False) – whether the input dictionary may contain serialized extended JSON constructs

Returns
classmethod from_json(s)

Loads the document from a JSON string.

Returns
get_field(field_name)

Gets the field of the document.

Parameters

field_name – the field name

Returns

the field value

Raises

AttributeError – if the field does not exist

has_field(field_name)

Determines whether the document has a field of the given name.

Parameters

field_name – the field name

Returns

True/False

set_field(field_name, value, create=False)

Sets the value of a field of the document.

Parameters
• field_name – the field name

• value – the field value

• create (False) – whether to create the field if it does not exist

Raises

ValueError – if field_name is not an allowed field name or does not exist and create == False

to_dict(extended=False)

Serializes this document to a BSON/JSON dictionary.

Parameters

extended (False) – whether to serialize extended JSON constructs such as ObjectIDs, Binary, etc. into JSON format

Returns

a dict

to_json(pretty_print=False)

Serializes the document to a JSON string.

Parameters

pretty_print (False) – whether to render the JSON in human readable format with newlines and indentations

Returns

a JSON string

class fiftyone.core.odm.document.DynamicDocument(*args, **values)

Bases: fiftyone.core.odm.document.BaseDocument, mongoengine.document.DynamicDocument

Base class for dynamic documents that are stored in a MongoDB collection. Dynamic documents can have arbitrary fields added to them. The ID of a document is automatically populated when it is added to the database, and the ID of a document is None if it has not been added to the database. .. attribute:: id

the ID of the document, or None if it has not been added to the database

Attributes:

 STRICT in_db Whether the document has been inserted into the database. pk Get the primary key.

Methods:

 cascade_save(**kwargs) Recursively save any references and generic references on the document. Hook for doing document level data cleaning before validation is run. clear_field(field_name) Clears the field from the document. Compares the indexes defined in MongoEngine with the ones existing in the database. Returns a deep copy of the document. create_index(keys[, background]) Creates the given indexes if required. delete([signal_kwargs]) Delete the Document from the database. Drops the entire collection associated with this Document type from the database. ensure_index(key_or_list[, background]) Ensure that the given indexes are in place. Checks the document meta data and ensures all the indexes exist. fancy_repr([class_name, select_fields, …]) Generates a customizable string representation of the document. field_to_mongo(field_name) field_to_python(field_name, value) from_dict(d[, extended]) Loads the document from a BSON/JSON dictionary. Loads the document from a JSON string. get_field(field_name) Gets the field of the document. Get text score from text query has_field(field_name) Determines whether the document has a field of the given name. Lists all of the indexes that should be created for given collection. modify([query]) Perform an atomic update of the document in the database and reload the document object using updated version. register_delete_rule(document_cls, …) This method registers the delete rules to apply when removing this object. reload(*fields, **kwargs) Reloads all attributes from the database. save([force_insert, validate, clean, …]) Save the Document to the database. select_related([max_depth]) Handles dereferencing of DBRef objects to a maximum depth in order to cut down the number queries to mongodb. set_field(field_name, value[, create]) Sets the value of a field of the document. switch_collection(collection_name[, …]) Temporarily switch the collection for a document instance. switch_db(db_alias[, keep_created]) Temporarily switch the database for a document instance. Returns an instance of DBRef useful in __raw__ queries. to_dict([extended]) Serializes this document to a BSON/JSON dictionary. to_json([pretty_print]) Serializes the document to a JSON string. to_mongo(*args, **kwargs) Return as SON data ready for use with MongoDB. update(**kwargs) Performs an update on the Document A convenience wrapper to update(). validate([clean]) Ensure that all fields’ values are valid and that required fields are present.

Classes:

 my_metaclass alias of mongoengine.base.metaclasses.TopLevelDocumentMetaclass
STRICT = False
cascade_save(**kwargs)

Recursively save any references and generic references on the document.

clean()

Hook for doing document level data cleaning before validation is run.

Any ValidationError raised by this method will not be associated with a particular field; it will have a special-case association with the field defined by NON_FIELD_ERRORS.

clear_field(field_name)

Clears the field from the document.

Parameters

field_name – the field name

Raises

ValueError – if the field does not exist

classmethod compare_indexes()

Compares the indexes defined in MongoEngine with the ones existing in the database. Returns any missing/extra indexes.

copy()

Returns a deep copy of the document.

Returns
classmethod create_index(keys, background=False, **kwargs)

Creates the given indexes if required.

Parameters
• keys – a single index key or a list of index keys (to construct a multi-field index); keys may be prefixed with a + or a - to determine the index ordering

• background – Allows index creation in the background

delete(signal_kwargs=None, **write_concern)

Delete the Document from the database. This will only take effect if the document has been previously saved.

Parameters
• signal_kwargs – (optional) kwargs dictionary to be passed to the signal calls.

• write_concern – Extra keyword arguments are passed down which will be used as options for the resultant getLastError command. For example, save(..., w: 2, fsync: True) will wait until at least two servers have recorded the write and will force an fsync on the primary server.

Changed in version 0.10.7: Add signal_kwargs argument

classmethod drop_collection()

Drops the entire collection associated with this Document type from the database.

Raises OperationError if the document has no collection set (i.g. if it is abstract)

Changed in version 0.10.7: OperationError exception raised if no collection available

classmethod ensure_index(key_or_list, background=False, **kwargs)

Ensure that the given indexes are in place. Deprecated in favour of create_index.

Parameters
• key_or_list – a single index key or a list of index keys (to construct a multi-field index); keys may be prefixed with a + or a - to determine the index ordering

• background – Allows index creation in the background

classmethod ensure_indexes()

Checks the document meta data and ensures all the indexes exist.

Global defaults can be set in the meta - see guide/defining-documents

Note

You can disable automatic index creation by setting auto_create_index to False in the documents meta data

fancy_repr(class_name=None, select_fields=None, exclude_fields=None, **kwargs)

Generates a customizable string representation of the document.

Parameters
• class_name (None) – optional class name to use

• select_fields (None) – iterable of field names to restrict to

• exclude_fields (None) – iterable of field names to exclude

• **kwargs – additional key-value pairs to include in the string representation

Returns

a string representation of the document

field_to_mongo(field_name)
field_to_python(field_name, value)
classmethod from_dict(d, extended=False)

Loads the document from a BSON/JSON dictionary.

Parameters
• d – a dictionary

• extended (False) – whether the input dictionary may contain serialized extended JSON constructs

Returns
classmethod from_json(s)

Loads the document from a JSON string.

Returns
get_field(field_name)

Gets the field of the document.

Parameters

field_name – the field name

Returns

the field value

Raises

AttributeError – if the field does not exist

get_text_score()

Get text score from text query

has_field(field_name)

Determines whether the document has a field of the given name.

Parameters

field_name – the field name

Returns

True/False

property in_db

Whether the document has been inserted into the database.

classmethod list_indexes()

Lists all of the indexes that should be created for given collection. It includes all the indexes from super- and sub-classes.

modify(query=None, **update)

Perform an atomic update of the document in the database and reload the document object using updated version.

Returns True if the document has been updated or False if the document in the database doesn’t match the query.

Note

All unsaved changes that have been made to the document are rejected if the method returns True.

Parameters
• query – the update will be performed only if the document in the database matches the query

• update – Django-style update keyword arguments

my_metaclass

alias of mongoengine.base.metaclasses.TopLevelDocumentMetaclass Methods:

 get_auto_id_names(new_class) Find a name for the automatic ID field for the given new class. mro Return a type’s method resolution order.
property pk

Get the primary key.

classmethod register_delete_rule(document_cls, field_name, rule)

This method registers the delete rules to apply when removing this object.

reload(*fields, **kwargs)

Reloads all attributes from the database.

Parameters
• fields – (optional) args list of fields to reload

• max_depth – (optional) depth of dereferencing to follow

New in version 0.1.2.

Changed in version 0.6: Now chainable

Changed in version 0.9: Can provide specific fields to reload

save(force_insert=False, validate=True, clean=True, write_concern=None, cascade=None, cascade_kwargs=None, _refs=None, save_condition=None, signal_kwargs=None, **kwargs)

Save the Document to the database. If the document already exists, it will be updated, otherwise it will be created. Returns the saved object instance.

Parameters
• force_insert – only try to create a new document, don’t allow updates of existing documents.

• validate – validates the document; set to False to skip.

• clean – call the document clean method, requires validate to be True.

• write_concern – Extra keyword arguments are passed down to save() OR insert() which will be used as options for the resultant getLastError command. For example, save(..., write_concern={w: 2, fsync: True}, ...) will wait until at least two servers have recorded the write and will force an fsync on the primary server.

• cascade – Sets the flag for cascading saves. You can set a default by setting “cascade” in the document __meta__

• cascade_kwargs – (optional) kwargs dictionary to be passed throw to cascading saves. Implies cascade=True.

• _refs – A list of processed references used in cascading saves

• save_condition – only perform save if matching record in db satisfies condition(s) (e.g. version number). Raises OperationError if the conditions are not satisfied

• signal_kwargs – (optional) kwargs dictionary to be passed to the signal calls.

Changed in version 0.5: In existing documents it only saves changed fields using set / unset. Saves are cascaded and any DBRef objects that have changes are saved as well.

Changed in version 0.8: Cascade saves are optional and default to False. If you want fine grain control then you can turn off using document meta[‘cascade’] = True. Also you can pass different kwargs to the cascade save using cascade_kwargs which overwrites the existing kwargs with custom values.

Changed in version 0.8.5: Optional save_condition that only overwrites existing documents if the condition is satisfied in the current db record.

Changed in version 0.10: OperationError exception raised if save_condition fails.

Changed in version 0.10.1: :class: save_condition failure now raises a SaveConditionError

Changed in version 0.10.7: Add signal_kwargs argument

Handles dereferencing of DBRef objects to a maximum depth in order to cut down the number queries to mongodb.

New in version 0.5.

set_field(field_name, value, create=False)

Sets the value of a field of the document.

Parameters
• field_name – the field name

• value – the field value

• create (False) – whether to create the field if it does not exist

Raises

ValueError – if field_name is not an allowed field name or does not exist and create == False

switch_collection(collection_name, keep_created=True)

Temporarily switch the collection for a document instance.

Only really useful for archiving off data and calling save():

user = User.objects.get(id=user_id)
user.switch_collection('old-users')
user.save()

Parameters
• collection_name (str) – The database alias to use for saving the document

• keep_created (bool) – keep self._created value after switching collection, else is reset to True

Use switch_db if you need to read from another database

switch_db(db_alias, keep_created=True)

Temporarily switch the database for a document instance.

Only really useful for archiving off data and calling save():

user = User.objects.get(id=user_id)
user.switch_db('archive-db')
user.save()

Parameters
• db_alias (str) – The database alias to use for saving the document

• keep_created (bool) – keep self._created value after switching db, else is reset to True

Use switch_collection if you need to read from another collection

to_dbref()

Returns an instance of DBRef useful in __raw__ queries.

to_dict(extended=False)

Serializes this document to a BSON/JSON dictionary.

Parameters

extended (False) – whether to serialize extended JSON constructs such as ObjectIDs, Binary, etc. into JSON format

Returns

a dict

to_json(pretty_print=False)

Serializes the document to a JSON string.

Parameters

pretty_print (False) – whether to render the JSON in human readable format with newlines and indentations

Returns

a JSON string

to_mongo(*args, **kwargs)

Return as SON data ready for use with MongoDB.

update(**kwargs)

Performs an update on the Document A convenience wrapper to update().

Raises OperationError if called on an object that has not yet been saved.

validate(clean=True)

Ensure that all fields’ values are valid and that required fields are present.

Raises ValidationError if any of the fields’ values are found to be invalid.

class fiftyone.core.odm.document.Document(*args, **values)

Bases: fiftyone.core.odm.document.BaseDocument, mongoengine.document.Document

Base class for documents that are stored in a MongoDB collection.

The ID of a document is automatically populated when it is added to the database, and the ID of a document is None if it has not been added to the database.

id

the ID of the document, or None if it has not been added to the database

Attributes:

 STRICT in_db Whether the document has been inserted into the database. pk Get the primary key.

Methods:

 cascade_save(**kwargs) Recursively save any references and generic references on the document. Hook for doing document level data cleaning before validation is run. clear_field(field_name) Clears the field from the document. Compares the indexes defined in MongoEngine with the ones existing in the database. Returns a deep copy of the document. create_index(keys[, background]) Creates the given indexes if required. delete([signal_kwargs]) Delete the Document from the database. Drops the entire collection associated with this Document type from the database. ensure_index(key_or_list[, background]) Ensure that the given indexes are in place. Checks the document meta data and ensures all the indexes exist. fancy_repr([class_name, select_fields, …]) Generates a customizable string representation of the document. field_to_mongo(field_name) field_to_python(field_name, value) from_dict(d[, extended]) Loads the document from a BSON/JSON dictionary. Loads the document from a JSON string. get_field(field_name) Gets the field of the document. Get text score from text query has_field(field_name) Determines whether the document has a field of the given name. Lists all of the indexes that should be created for given collection. modify([query]) Perform an atomic update of the document in the database and reload the document object using updated version. register_delete_rule(document_cls, …) This method registers the delete rules to apply when removing this object. reload(*fields, **kwargs) Reloads all attributes from the database. save([validate, clean]) Save the Document to the database. select_related([max_depth]) Handles dereferencing of DBRef objects to a maximum depth in order to cut down the number queries to mongodb. set_field(field_name, value[, create]) Sets the value of a field of the document. switch_collection(collection_name[, …]) Temporarily switch the collection for a document instance. switch_db(db_alias[, keep_created]) Temporarily switch the database for a document instance. Returns an instance of DBRef useful in __raw__ queries. to_dict([extended]) Serializes this document to a BSON/JSON dictionary. to_json([pretty_print]) Serializes the document to a JSON string. to_mongo(*args, **kwargs) Return as SON data ready for use with MongoDB. update(**kwargs) Performs an update on the Document A convenience wrapper to update(). validate([clean]) Ensure that all fields’ values are valid and that required fields are present.

Classes:

 my_metaclass alias of mongoengine.base.metaclasses.TopLevelDocumentMetaclass
save(validate=True, clean=True, **kwargs)

Save the Document to the database.

If the document already exists, it will be updated, otherwise it will be created.

Parameters
• validate (True) – validates the document

• clean (True) – call the document’s clean method; requires validate to be True

Returns

self

STRICT = False
cascade_save(**kwargs)

Recursively save any references and generic references on the document.

clean()

Hook for doing document level data cleaning before validation is run.

Any ValidationError raised by this method will not be associated with a particular field; it will have a special-case association with the field defined by NON_FIELD_ERRORS.

clear_field(field_name)

Clears the field from the document.

Parameters

field_name – the field name

Raises

ValueError – if the field does not exist

classmethod compare_indexes()

Compares the indexes defined in MongoEngine with the ones existing in the database. Returns any missing/extra indexes.

copy()

Returns a deep copy of the document.

Returns
classmethod create_index(keys, background=False, **kwargs)

Creates the given indexes if required.

Parameters
• keys – a single index key or a list of index keys (to construct a multi-field index); keys may be prefixed with a + or a - to determine the index ordering

• background – Allows index creation in the background

delete(signal_kwargs=None, **write_concern)

Delete the Document from the database. This will only take effect if the document has been previously saved.

Parameters
• signal_kwargs – (optional) kwargs dictionary to be passed to the signal calls.

• write_concern – Extra keyword arguments are passed down which will be used as options for the resultant getLastError command. For example, save(..., w: 2, fsync: True) will wait until at least two servers have recorded the write and will force an fsync on the primary server.

Changed in version 0.10.7: Add signal_kwargs argument

classmethod drop_collection()

Drops the entire collection associated with this Document type from the database.

Raises OperationError if the document has no collection set (i.g. if it is abstract)

Changed in version 0.10.7: OperationError exception raised if no collection available

classmethod ensure_index(key_or_list, background=False, **kwargs)

Ensure that the given indexes are in place. Deprecated in favour of create_index.

Parameters
• key_or_list – a single index key or a list of index keys (to construct a multi-field index); keys may be prefixed with a + or a - to determine the index ordering

• background – Allows index creation in the background

classmethod ensure_indexes()

Checks the document meta data and ensures all the indexes exist.

Global defaults can be set in the meta - see guide/defining-documents

Note

You can disable automatic index creation by setting auto_create_index to False in the documents meta data

fancy_repr(class_name=None, select_fields=None, exclude_fields=None, **kwargs)

Generates a customizable string representation of the document.

Parameters
• class_name (None) – optional class name to use

• select_fields (None) – iterable of field names to restrict to

• exclude_fields (None) – iterable of field names to exclude

• **kwargs – additional key-value pairs to include in the string representation

Returns

a string representation of the document

field_to_mongo(field_name)
field_to_python(field_name, value)
classmethod from_dict(d, extended=False)

Loads the document from a BSON/JSON dictionary.

Parameters
• d – a dictionary

• extended (False) – whether the input dictionary may contain serialized extended JSON constructs

Returns
classmethod from_json(s)

Loads the document from a JSON string.

Returns
get_field(field_name)

Gets the field of the document.

Parameters

field_name – the field name

Returns

the field value

Raises

AttributeError – if the field does not exist

get_text_score()

Get text score from text query

has_field(field_name)

Determines whether the document has a field of the given name.

Parameters

field_name – the field name

Returns

True/False

property in_db

Whether the document has been inserted into the database.

classmethod list_indexes()

Lists all of the indexes that should be created for given collection. It includes all the indexes from super- and sub-classes.

modify(query=None, **update)

Perform an atomic update of the document in the database and reload the document object using updated version.

Returns True if the document has been updated or False if the document in the database doesn’t match the query.

Note

All unsaved changes that have been made to the document are rejected if the method returns True.

Parameters
• query – the update will be performed only if the document in the database matches the query

• update – Django-style update keyword arguments

my_metaclass

alias of mongoengine.base.metaclasses.TopLevelDocumentMetaclass Methods:

 get_auto_id_names(new_class) Find a name for the automatic ID field for the given new class. mro Return a type’s method resolution order.
property pk

Get the primary key.

classmethod register_delete_rule(document_cls, field_name, rule)

This method registers the delete rules to apply when removing this object.

reload(*fields, **kwargs)

Reloads all attributes from the database.

Parameters
• fields – (optional) args list of fields to reload

• max_depth – (optional) depth of dereferencing to follow

New in version 0.1.2.

Changed in version 0.6: Now chainable

Changed in version 0.9: Can provide specific fields to reload

Handles dereferencing of DBRef objects to a maximum depth in order to cut down the number queries to mongodb.

New in version 0.5.

set_field(field_name, value, create=False)

Sets the value of a field of the document.

Parameters
• field_name – the field name

• value – the field value

• create (False) – whether to create the field if it does not exist

Raises

ValueError – if field_name is not an allowed field name or does not exist and create == False

switch_collection(collection_name, keep_created=True)

Temporarily switch the collection for a document instance.

Only really useful for archiving off data and calling save():

user = User.objects.get(id=user_id)
user.switch_collection('old-users')
user.save()

Parameters
• collection_name (str) – The database alias to use for saving the document

• keep_created (bool) – keep self._created value after switching collection, else is reset to True

Use switch_db if you need to read from another database

switch_db(db_alias, keep_created=True)

Temporarily switch the database for a document instance.

Only really useful for archiving off data and calling save():

user = User.objects.get(id=user_id)
user.switch_db('archive-db')
user.save()

Parameters
• db_alias (str) – The database alias to use for saving the document

• keep_created (bool) – keep self._created value after switching db, else is reset to True

Use switch_collection if you need to read from another collection

to_dbref()

Returns an instance of DBRef useful in __raw__ queries.

to_dict(extended=False)

Serializes this document to a BSON/JSON dictionary.

Parameters

extended (False) – whether to serialize extended JSON constructs such as ObjectIDs, Binary, etc. into JSON format

Returns

a dict

to_json(pretty_print=False)

Serializes the document to a JSON string.

Parameters

pretty_print (False) – whether to render the JSON in human readable format with newlines and indentations

Returns

a JSON string

to_mongo(*args, **kwargs)

Return as SON data ready for use with MongoDB.

update(**kwargs)

Performs an update on the Document A convenience wrapper to update().

Raises OperationError if called on an object that has not yet been saved.

validate(clean=True)

Ensure that all fields’ values are valid and that required fields are present.

Raises ValidationError if any of the fields’ values are found to be invalid.