mongoengine.connect(db=None, alias='default', **kwargs)¶Connect to the database specified by the ‘db’ argument.
Connection settings may be provided here as well if the database is not running on the default port on localhost. If authentication is needed, provide username and password arguments as well.
Multiple databases are supported by using aliases. Provide a separate alias to connect to a different instance of mongod.
Changed in version 0.6: - added multiple database support.
mongoengine.register_connection(alias, name=None, host=None, port=None, read_preference=Primary(), username=None, password=None, authentication_source=None, authentication_mechanism=None, **kwargs)¶Add a connection.
| Parameters: |
|
|---|
Changed in version 0.10.6: - added mongomock support
mongoengine.Document(*args, **values)¶The base class used for defining the structure and properties of
collections of documents stored in MongoDB. Inherit from this class, and
add fields as class attributes to define a document’s structure.
Individual documents may then be created by making instances of the
Document subclass.
By default, the MongoDB collection used to store documents created using a
Document subclass will be the name of the subclass
converted to lowercase. A different collection may be specified by
providing collection to the meta dictionary in the class
definition.
A Document subclass may be itself subclassed, to
create a specialised version of the document that will be stored in the
same collection. To facilitate this behaviour a _cls
field is added to documents (hidden though the MongoEngine interface).
To enable this behaviourset allow_inheritance to True in the
meta dictionary.
A Document may use a Capped Collection by
specifying max_documents and max_size in the meta
dictionary. max_documents is the maximum number of documents that
is allowed to be stored in the collection, and max_size is the
maximum size of the collection in bytes. max_size is rounded up
to the next multiple of 256 by MongoDB internally and mongoengine before.
Use also a multiple of 256 to avoid confusions. If max_size is not
specified and max_documents is, max_size defaults to
10485760 bytes (10MB).
Indexes may be created by specifying indexes in the meta
dictionary. The value should be a list of field names or tuples of field
names. Index direction may be specified by prefixing the field names with
a + or - sign.
Automatic index creation can be disabled by specifying
auto_create_index in the meta dictionary. If this is set to
False then indexes will not be created by MongoEngine. This is useful in
production systems where index creation is performed as part of a
deployment system.
By default, _cls will be added to the start of every index (that doesn’t contain a list) if allow_inheritance is True. This can be disabled by either setting cls to False on the specific index or by setting index_cls to False on the meta dictionary for the document.
By default, any extra attribute existing in stored data but not declared
in your model will raise a FieldDoesNotExist error.
This can be disabled by setting strict to False
in the meta dictionary.
Initialise a document or embedded document
| Parameters: |
|
|---|
cascade_save(**kwargs)¶Recursively save any references and generic references on the document.
compare_indexes()¶Compares the indexes defined in MongoEngine with the ones existing in the database. Returns any missing/extra indexes.
create_index(keys, background=False, **kwargs)¶Creates the given indexes if required.
| Parameters: |
|
|---|
delete(signal_kwargs=None, **write_concern)¶Delete the Document from the database. This
will only take effect if the document has been previously saved.
| Parm signal_kwargs: | |
|---|---|
| (optional) kwargs dictionary to be passed to the signal calls. | |
| Parameters: | write_concern – Extra keyword arguments are passed down 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. |
Changed in version 0.10.7: Add signal_kwargs argument
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
ensure_index(key_or_list, drop_dups=False, background=False, **kwargs)¶Ensure that the given indexes are in place. Deprecated in favour of create_index.
| Parameters: |
|
|---|
ensure_indexes()¶Checks the document meta data and ensures all the indexes exist.
Global defaults can be set in the meta - see Defining documents
Note
You can disable automatic index creation by setting auto_create_index to False in the documents meta data
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: |
|
|---|
my_metaclass¶alias of TopLevelDocumentMetaclass
pk¶Get the primary key.
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: |
|
|---|
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.
| Parameters: |
|
|---|---|
| Parm 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 0.6: Added cascading saves
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.
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: |
|
|---|
See also
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: |
|
|---|
See also
Use switch_collection
if you need to read from another collection
to_dbref()¶Returns an instance of DBRef useful in
__raw__ queries.
mongoengine.EmbeddedDocument(*args, **kwargs)¶A Document that isn’t stored in its own
collection. EmbeddedDocuments should be used as
fields on Documents through the
EmbeddedDocumentField field type.
A EmbeddedDocument subclass may be itself subclassed,
to create a specialised version of the embedded document that will be
stored in the same collection. To facilitate this behaviour a _cls
field is added to documents (hidden though the MongoEngine interface).
To enable this behaviour set allow_inheritance to True in the
meta dictionary.
my_metaclass¶alias of DocumentMetaclass
mongoengine.DynamicDocument(*args, **values)¶A Dynamic Document class allowing flexible, expandable and uncontrolled
schemas. As a Document subclass, acts in the same
way as an ordinary document but has expando style properties. Any data
passed or set against the DynamicDocument that is
not a field is automatically converted into a
DynamicField and data can be attributed to that
field.
Note
There is one caveat on Dynamic Documents: fields cannot start with _
Initialise a document or embedded document
| Parameters: |
|
|---|
my_metaclass¶alias of TopLevelDocumentMetaclass
mongoengine.DynamicEmbeddedDocument(*args, **kwargs)¶A Dynamic Embedded Document class allowing flexible, expandable and
uncontrolled schemas. See DynamicDocument for more
information about dynamic documents.
my_metaclass¶alias of DocumentMetaclass
mongoengine.document.MapReduceDocument(document, collection, key, value)¶A document returned from a map/reduce query.
| Parameters: |
|
|---|
New in version 0.3.
object¶Lazy-load the object referenced by self.key. self.key
should be the primary_key.
mongoengine.ValidationError(message='', **kwargs)¶Validation exception.
May represent an error validating a field or a document containing fields with validation errors.
| Variables: | errors – A dictionary of errors for fields within this document or list, or None if the error is for an individual field. |
|---|
to_dict()¶Returns a dictionary of all errors within a document
Keys are field names or list indices and values are the validation error messages, or a nested dictionary of errors for an embedded document or list.
mongoengine.FieldDoesNotExist¶Raised when trying to set a field
not declared in a Document
or an EmbeddedDocument.
To avoid this behavior on data loading,
you should the strict to False
in the meta dictionnary.
mongoengine.context_managers.switch_db(cls, db_alias)¶switch_db alias context manager.
Example
# Register connections
register_connection('default', 'mongoenginetest')
register_connection('testdb-1', 'mongoenginetest2')
class Group(Document):
name = StringField()
Group(name='test').save() # Saves in the default db
with switch_db(Group, 'testdb-1') as Group:
Group(name='hello testdb!').save() # Saves in testdb-1
Construct the switch_db context manager
| Parameters: |
|
|---|
mongoengine.context_managers.switch_collection(cls, collection_name)¶switch_collection alias context manager.
Example
class Group(Document):
name = StringField()
Group(name='test').save() # Saves in the default db
with switch_collection(Group, 'group1') as Group:
Group(name='hello testdb!').save() # Saves in group1 collection
Construct the switch_collection context manager.
| Parameters: |
|
|---|
mongoengine.context_managers.no_dereference(cls)¶no_dereference context manager.
Turns off all dereferencing in Documents for the duration of the context manager:
with no_dereference(Group) as Group:
Group.objects.find()
Construct the no_dereference context manager.
| Parameters: | cls – the class to turn dereferencing off on |
|---|
mongoengine.context_managers.query_counter¶Query_counter context manager to get the number of queries.
Construct the query_counter.
mongoengine.queryset.QuerySet(document, collection)¶The default queryset, that builds queries and handles a set of results returned from a query.
Wraps a MongoDB cursor, providing Document objects as
the results.
__call__(q_obj=None, class_check=True, read_preference=None, **query)¶Filter the selected documents by calling the
QuerySet with a query.
| Parameters: |
|
|---|
aggregate(*pipeline, **kwargs)¶Perform a aggregate function based in your queryset params :param pipeline: list of aggregation commands, see: http://docs.mongodb.org/manual/core/aggregation-pipeline/
New in version 0.9.
all()¶Returns all documents.
all_fields()¶Include all fields. Reset all previously calls of .only() or .exclude().
post = BlogPost.objects.exclude('comments').all_fields()
New in version 0.5.
as_pymongo(coerce_types=False)¶Instead of returning Document instances, return raw values from pymongo.
| Parameters: | coerce_types – Field types (if applicable) would be use to coerce types. |
|---|
average(field)¶Average over the values of the specified field.
| Parameters: | field – the field to average over; use dot notation to refer to embedded document fields |
|---|
batch_size(size)¶Limit the number of documents returned in a single batch (each batch requires a round trip to the server).
See http://api.mongodb.com/python/current/api/pymongo/cursor.html#pymongo.cursor.Cursor.batch_size for details.
| Parameters: | size – desired size of each batch. |
|---|
clone_into(cls)¶Creates a copy of the current
BaseQuerySet into another child class
comment(text)¶Add a comment to the query.
See https://docs.mongodb.com/manual/reference/method/cursor.comment/#cursor.comment for details.
count(with_limit_and_skip=False)¶Count the selected elements in the query.
| Parameters: | (optional) (with_limit_and_skip) – take any limit() or
skip() that has been applied to this cursor into account when
getting the count |
|---|
create(**kwargs)¶Create new object. Returns the saved object instance.
New in version 0.4.
delete(write_concern=None, _from_doc_delete=False, cascade_refs=None)¶Delete the documents matched by the query.
| Parameters: |
|
|---|
:returns number of deleted documents
distinct(field)¶Return a list of distinct values for a given field.
| Parameters: | field – the field to select distinct values from |
|---|
Note
This is a command and won’t take ordering or limit into account.
New in version 0.4.
Changed in version 0.5: - Fixed handling references
Changed in version 0.6: - Improved db_field refrence handling
ensure_index(**kwargs)¶Deprecated use Document.ensure_index()
exclude(*fields)¶Opposite to .only(), exclude some document’s fields.
post = BlogPost.objects(...).exclude('comments')
Note
exclude() is chainable and will perform a union :: So with the following it will exclude both: title and author.name:
post = BlogPost.objects.exclude('title').exclude('author.name')
all_fields() will reset any
field filters.
| Parameters: | fields – fields to exclude |
|---|
New in version 0.5.
exec_js(code, *fields, **options)¶Execute a Javascript function on the server. A list of fields may be
provided, which will be translated to their correct names and supplied
as the arguments to the function. A few extra variables are added to
the function’s scope: collection, which is the name of the
collection in use; query, which is an object representing the
current query; and options, which is an object containing any
options specified as keyword arguments.
As fields in MongoEngine may use different names in the database (set
using the db_field keyword argument to a Field
constructor), a mechanism exists for replacing MongoEngine field names
with the database field names in Javascript code. When accessing a
field, use square-bracket notation, and prefix the MongoEngine field
name with a tilde (~).
| Parameters: |
|
|---|
explain(format=False)¶Return an explain plan record for the
QuerySet‘s cursor.
| Parameters: | format – format the plan before returning it |
|---|
fields(_only_called=False, **kwargs)¶Manipulate how you load this document’s fields. Used by .only() and .exclude() to manipulate which fields to retrieve. Fields also allows for a greater level of control for example:
Retrieving a Subrange of Array Elements:
You can use the $slice operator to retrieve a subrange of elements in an array. For example to get the first 5 comments:
post = BlogPost.objects(...).fields(slice__comments=5)
| Parameters: | kwargs – A dictionary identifying what to include |
|---|
New in version 0.5.
filter(*q_objs, **query)¶An alias of __call__()
first()¶Retrieve the first object matching the query.
from_json(json_data)¶Converts json data to unsaved objects
get(*q_objs, **query)¶Retrieve the the matching object raising
MultipleObjectsReturned or
DocumentName.MultipleObjectsReturned exception if multiple results
and DoesNotExist or
DocumentName.DoesNotExist if no results are found.
New in version 0.3.
hint(index=None)¶Added ‘hint’ support, telling Mongo the proper index to use for the query.
Judicious use of hints can greatly improve query performance. When doing a query on multiple fields (at least one of which is indexed) pass the indexed field as a hint to the query.
Hinting will not do anything if the corresponding index does not exist. The last hint applied to this cursor takes precedence over all others.
New in version 0.5.
in_bulk(object_ids)¶Retrieve a set of documents by their ids.
| Parameters: | object_ids – a list or tuple of ObjectIds |
|---|---|
| Return type: | dict of ObjectIds as keys and collection-specific Document subclasses as values. |
New in version 0.3.
insert(doc_or_docs, load_bulk=True, write_concern=None, signal_kwargs=None)¶bulk insert documents
| Parameters: |
|
|---|---|
| Parm signal_kwargs: | |
(optional) kwargs dictionary to be passed to the signal calls. |
|
By default returns document instances, set load_bulk to False to
return just ObjectIds
New in version 0.5.
Changed in version 0.10.7: Add signal_kwargs argument
item_frequencies(field, normalize=False, map_reduce=True)¶Returns a dictionary of all items present in a field across the whole queried set of documents, and their corresponding frequency. This is useful for generating tag clouds, or searching documents.
Note
Can only do direct simple mappings and cannot map across
ReferenceField or
GenericReferenceField for more complex
counting a manual map reduce call is required.
If the field is a ListField, the items within
each list will be counted individually.
| Parameters: |
|
|---|
Changed in version 0.5: defaults to map_reduce and can handle embedded document lookups
limit(n)¶Limit the number of returned documents to n. This may also be
achieved using array-slicing syntax (e.g. User.objects[:5]).
| Parameters: | n – the maximum number of objects to return |
|---|
map_reduce(map_f, reduce_f, output, finalize_f=None, limit=None, scope=None)¶Perform a map/reduce query using the current query spec
and ordering. While map_reduce respects QuerySet chaining,
it must be the last call made, as it does not return a maleable
QuerySet.
See the test_map_reduce()
and test_map_advanced()
tests in tests.queryset.QuerySetTest for usage examples.
| Parameters: |
|
|---|
Returns an iterator yielding
MapReduceDocument.
Note
Map/Reduce changed in server version >= 1.7.4. The PyMongo
map_reduce() helper requires
PyMongo version >= 1.11.
Changed in version 0.5: - removed keep_temp keyword argument, which was only relevant
for MongoDB server versions older than 1.7.4
New in version 0.3.
max_time_ms(ms)¶Wait ms milliseconds before killing the query on the server
| Parameters: | ms – the number of milliseconds before killing the query on the server |
|---|
modify(upsert=False, full_response=False, remove=False, new=False, **update)¶Update and return the updated document.
Returns either the document before or after modification based on new
parameter. If no documents match the query and upsert is false,
returns None. If upserting and new is false, returns None.
If the full_response parameter is True, the return value will be
the entire response object from the server, including the ‘ok’ and
‘lastErrorObject’ fields, rather than just the modified document.
This is useful mainly because the ‘lastErrorObject’ document holds
information about the command’s execution.
| Parameters: |
|
|---|
New in version 0.9.
no_cache()¶Convert to a non_caching queryset
New in version 0.8.3: Convert to non caching queryset
no_dereference()¶Turn off any dereferencing for the results of this queryset.
no_sub_classes()¶Only return instances of this document and not any inherited documents
none()¶Helper that just returns a list
only(*fields)¶Load only a subset of this document’s fields.
post = BlogPost.objects(...).only('title', 'author.name')
Note
only() is chainable and will perform a union :: So with the following it will fetch both: title and author.name:
post = BlogPost.objects.only('title').only('author.name')
all_fields() will reset any
field filters.
| Parameters: | fields – fields to include |
|---|
New in version 0.3.
Changed in version 0.5: - Added subfield support
order_by(*keys)¶Order the QuerySet by the keys. The
order may be specified by prepending each of the keys by a + or a -.
Ascending order is assumed.
| Parameters: | keys – fields to order the query results by; keys may be prefixed with + or - to determine the ordering direction |
|---|
read_preference(read_preference)¶Change the read_preference when querying.
| Parameters: | read_preference – override ReplicaSetConnection-level preference. |
|---|
rewind()¶Rewind the cursor to its unevaluated state.
New in version 0.3.
scalar(*fields)¶Instead of returning Document instances, return either a specific value or a tuple of values in order.
Can be used along with
no_dereference() to turn off
dereferencing.
Note
This effects all results and can be unset by calling
scalar without arguments. Calls only automatically.
| Parameters: | fields – One or more fields to return instead of a Document. |
|---|
search_text(text, language=None)¶Start a text search, using text indexes. Require: MongoDB server version 2.6+.
| Parameters: | language – The language that determines the list of stop words for the search and the rules for the stemmer and tokenizer. If not specified, the search uses the default language of the index. For supported languages, see Text Search Languages <http://docs.mongodb.org/manual/reference/text-search-languages/#text-search-languages>. |
|---|
Handles dereferencing of DBRef objects or
ObjectId a maximum depth in order to cut down
the number queries to mongodb.
New in version 0.5.
skip(n)¶Skip n documents before returning the results. This may also be
achieved using array-slicing syntax (e.g. User.objects[5:]).
| Parameters: | n – the number of objects to skip before returning results |
|---|
slave_okay(enabled)¶Enable or disable the slave_okay when querying.
| Parameters: | enabled – whether or not the slave_okay is enabled |
|---|
Deprecated since version Ignored: with PyMongo 3+
snapshot(enabled)¶Enable or disable snapshot mode when querying.
| Parameters: | enabled – whether or not snapshot mode is enabled |
|---|
..versionchanged:: 0.5 - made chainable .. deprecated:: Ignored with PyMongo 3+
sum(field)¶Sum over the values of the specified field.
| Parameters: | field – the field to sum over; use dot notation to refer to embedded document fields |
|---|
timeout(enabled)¶Enable or disable the default mongod timeout when querying.
| Parameters: | enabled – whether or not the timeout is used |
|---|
..versionchanged:: 0.5 - made chainable
to_json(*args, **kwargs)¶Converts a queryset to JSON
update(upsert=False, multi=True, write_concern=None, full_result=False, **update)¶Perform an atomic update on the fields matched by the query.
| Parameters: |
|
|---|
New in version 0.2.
update_one(upsert=False, write_concern=None, **update)¶Perform an atomic update on the fields of the first document matched by the query.
| Parameters: |
|
|---|
New in version 0.2.
upsert_one(write_concern=None, **update)¶Overwrite or add the first document matched by the query.
| Parameters: |
|
|---|
:returns the new or overwritten document
New in version 0.10.2.
using(alias)¶This method is for controlling which database the QuerySet will be evaluated against if you are using more than one database.
| Parameters: | alias – The database alias |
|---|
New in version 0.9.
values_list(*fields)¶An alias for scalar
where(where_clause)¶Filter QuerySet results with a $where clause (a Javascript
expression). Performs automatic field name substitution like
mongoengine.queryset.Queryset.exec_js().
Note
When using this mode of query, the database will call your function, or evaluate your predicate clause, for each object in the collection.
New in version 0.5.
with_id(object_id)¶Retrieve the object matching the id provided. Uses object_id only and raises InvalidQueryError if a filter has been applied. Returns None if no document exists with that id.
| Parameters: | object_id – the value for the id of the document to look up |
|---|
Changed in version 0.6: Raises InvalidQueryError if filter has been set
mongoengine.queryset.QuerySetNoCache(document, collection)¶A non caching QuerySet
__call__(q_obj=None, class_check=True, read_preference=None, **query)¶Filter the selected documents by calling the
QuerySetwith a query.
Parameters:
- q_obj – a
Qobject to be used in the query; theQuerySetis filtered multiple times with differentQobjects, only the last one will be used- class_check – If set to False bypass class name check when querying collection
- read_preference – if set, overrides connection-level read_preference from ReplicaSetConnection.
- query – Django-style query keyword arguments
cache()¶Convert to a caching queryset
New in version 0.8.3: Convert to caching queryset
mongoengine.queryset.queryset_manager(func)¶Decorator that allows you to define custom QuerySet managers on
Document classes. The manager must be a function that
accepts a Document class as its first argument, and a
QuerySet as its second argument. The method
function should return a QuerySet, probably
the same one that was passed in, but modified in some way.
mongoengine.base.fields.BaseField(db_field=None, name=None, required=False, default=None, unique=False, unique_with=None, primary_key=False, validation=None, choices=None, null=False, sparse=False, **kwargs)¶A base class for fields in a MongoDB document. Instances of this class may be added to subclasses of Document to define a document’s schema.
Changed in version 0.5: - added verbose and help text
| Parameters: |
|
|---|
mongoengine.fields.StringField(regex=None, max_length=None, min_length=None, **kwargs)¶A unicode string field.
mongoengine.fields.URLField(verify_exists=False, url_regex=None, schemes=None, **kwargs)¶A field that validates input as an URL.
New in version 0.3.
mongoengine.fields.EmailField(regex=None, max_length=None, min_length=None, **kwargs)¶A field that validates input as an email address.
New in version 0.4.
mongoengine.fields.IntField(min_value=None, max_value=None, **kwargs)¶32-bit integer field.
mongoengine.fields.LongField(min_value=None, max_value=None, **kwargs)¶64-bit integer field.
mongoengine.fields.FloatField(min_value=None, max_value=None, **kwargs)¶Floating point number field.
mongoengine.fields.DecimalField(min_value=None, max_value=None, force_string=False, precision=2, rounding='ROUND_HALF_UP', **kwargs)¶Fixed-point decimal number field.
Changed in version 0.8.
New in version 0.3.
| Parameters: |
|
|---|
mongoengine.fields.BooleanField(db_field=None, name=None, required=False, default=None, unique=False, unique_with=None, primary_key=False, validation=None, choices=None, null=False, sparse=False, **kwargs)¶Boolean field type.
New in version 0.1.2.
| Parameters: |
|
|---|
mongoengine.fields.DateTimeField(db_field=None, name=None, required=False, default=None, unique=False, unique_with=None, primary_key=False, validation=None, choices=None, null=False, sparse=False, **kwargs)¶Datetime field.
Uses the python-dateutil library if available alternatively use time.strptime to parse the dates. Note: python-dateutil’s parser is fully featured and when installed you can utilise it to convert varying types of date formats into valid python datetime objects.
ComplexDateTimeField if you
need accurate microsecond support.| Parameters: |
|
|---|
mongoengine.fields.ComplexDateTimeField(separator=', ', **kwargs)¶ComplexDateTimeField handles microseconds exactly instead of rounding like DateTimeField does.
Derives from a StringField so you can do gte and lte filtering by using lexicographical comparison when filtering / sorting strings.
The stored string has the following format:
YYYY,MM,DD,HH,MM,SS,NNNNNN
Where NNNNNN is the number of microseconds of the represented datetime. The , as the separator can be easily modified by passing the separator keyword when initializing the field.
New in version 0.5.
mongoengine.fields.EmbeddedDocumentField(document_type, **kwargs)¶An embedded document field - with a declared document_type.
Only valid values are subclasses of EmbeddedDocument.
mongoengine.fields.GenericEmbeddedDocumentField(db_field=None, name=None, required=False, default=None, unique=False, unique_with=None, primary_key=False, validation=None, choices=None, null=False, sparse=False, **kwargs)¶A generic embedded document field - allows any
EmbeddedDocument to be stored.
Only valid values are subclasses of EmbeddedDocument.
Note
You can use the choices param to limit the acceptable EmbeddedDocument types
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mongoengine.fields.DynamicField(db_field=None, name=None, required=False, default=None, unique=False, unique_with=None, primary_key=False, validation=None, choices=None, null=False, sparse=False, **kwargs)¶A truly dynamic field type capable of handling different and varying types of data.
Used by DynamicDocument to handle dynamic data
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mongoengine.fields.ListField(field=None, **kwargs)¶A list field that wraps a standard field, allowing multiple instances of the field to be used as a list in the database.
If using with ReferenceFields see: One to Many with ListFields
Note
Required means it cannot be empty - as the default for ListFields is []
mongoengine.fields.EmbeddedDocumentListField(document_type, **kwargs)¶A ListField designed specially to hold a list of
embedded documents to provide additional query helpers.
Note
The only valid list values are subclasses of
EmbeddedDocument.
New in version 0.9.
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mongoengine.fields.SortedListField(field, **kwargs)¶A ListField that sorts the contents of its list before writing to the database in order to ensure that a sorted list is always retrieved.
Warning
There is a potential race condition when handling lists. If you set / save the whole list then other processes trying to save the whole list as well could overwrite changes. The safest way to append to a list is to perform a push operation.
New in version 0.4.
Changed in version 0.6: - added reverse keyword
mongoengine.fields.DictField(basecls=None, field=None, *args, **kwargs)¶A dictionary field that wraps a standard Python dictionary. This is similar to an embedded document, but the structure is not defined.
Note
Required means it cannot be empty - as the default for DictFields is {}
New in version 0.3.
Changed in version 0.5: - Can now handle complex / varying types of data
mongoengine.fields.MapField(field=None, *args, **kwargs)¶A field that maps a name to a specified field type. Similar to a DictField, except the ‘value’ of each item must match the specified field type.
New in version 0.5.
mongoengine.fields.ReferenceField(document_type, dbref=False, reverse_delete_rule=0, **kwargs)¶A reference to a document that will be automatically dereferenced on access (lazily).
Use the reverse_delete_rule to handle what should happen if the document the field is referencing is deleted. EmbeddedDocuments, DictFields and MapFields does not support reverse_delete_rule and an InvalidDocumentError will be raised if trying to set on one of these Document / Field types.
The options are:
- DO_NOTHING (0) - don’t do anything (default).
- NULLIFY (1) - Updates the reference to null.
- CASCADE (2) - Deletes the documents associated with the reference.
- DENY (3) - Prevent the deletion of the reference object.
- PULL (4) - Pull the reference from a
ListFieldof references
Alternative syntax for registering delete rules (useful when implementing bi-directional delete rules)
class Bar(Document):
content = StringField()
foo = ReferenceField('Foo')
Foo.register_delete_rule(Bar, 'foo', NULLIFY)
Note
reverse_delete_rule does not trigger pre / post delete signals to be triggered.
Changed in version 0.5: added reverse_delete_rule
Initialises the Reference Field.
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Note
A reference to an abstract document type is always stored as a
DBRef, regardless of the value of dbref.
mongoengine.fields.GenericReferenceField(*args, **kwargs)¶A reference to any Document subclass
that will be automatically dereferenced on access (lazily).
Note
New in version 0.3.
mongoengine.fields.CachedReferenceField(document_type, fields=None, auto_sync=True, **kwargs)¶A referencefield with cache fields to purpose pseudo-joins
New in version 0.9.
Initialises the Cached Reference Field.
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mongoengine.fields.BinaryField(max_bytes=None, **kwargs)¶A binary data field.
mongoengine.fields.FileField(db_alias='default', collection_name='fs', **kwargs)¶A GridFS storage field.
New in version 0.4.
Changed in version 0.5: added optional size param for read
Changed in version 0.6: added db_alias for multidb support
mongoengine.fields.ImageField(size=None, thumbnail_size=None, collection_name='images', **kwargs)¶A Image File storage field.
New in version 0.6.
mongoengine.fields.SequenceField(collection_name=None, db_alias=None, sequence_name=None, value_decorator=None, *args, **kwargs)¶Note
Although traditional databases often use increasing sequence numbers for primary keys. In MongoDB, the preferred approach is to use Object IDs instead. The concept is that in a very large cluster of machines, it is easier to create an object ID than have global, uniformly increasing sequence numbers.
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Use any callable as value_decorator to transform calculated counter into any value suitable for your needs, e.g. string or hexadecimal representation of the default integer counter value.
Note
In case the counter is defined in the abstract document, it will be common to all inherited documents and the default sequence name will be the class name of the abstract document.
New in version 0.5.
Changed in version 0.8: added value_decorator
mongoengine.fields.ObjectIdField(db_field=None, name=None, required=False, default=None, unique=False, unique_with=None, primary_key=False, validation=None, choices=None, null=False, sparse=False, **kwargs)¶A field wrapper around MongoDB’s ObjectIds.
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mongoengine.fields.UUIDField(binary=True, **kwargs)¶A UUID field.
New in version 0.6.
Store UUID data in the database
| Parameters: | binary – if False store as a string. |
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Changed in version 0.8.0.
Changed in version 0.6.19.
mongoengine.fields.GeoPointField(db_field=None, name=None, required=False, default=None, unique=False, unique_with=None, primary_key=False, validation=None, choices=None, null=False, sparse=False, **kwargs)¶A list storing a longitude and latitude coordinate.
Note
this represents a generic point in a 2D plane and a legacy way of representing a geo point. It admits 2d indexes but not “2dsphere” indexes in MongoDB > 2.4 which are more natural for modeling geospatial points. See Geospatial indexes
New in version 0.4.
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mongoengine.fields.PointField(auto_index=True, *args, **kwargs)¶A GeoJSON field storing a longitude and latitude coordinate.
The data is represented as:
{'type' : 'Point' ,
'coordinates' : [x, y]}
You can either pass a dict with the full information or a list to set the value.
Requires mongodb >= 2.4
New in version 0.8.
| Parameters: | auto_index (bool) – Automatically create a ‘2dsphere’ index. Defaults to True. |
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mongoengine.fields.LineStringField(auto_index=True, *args, **kwargs)¶A GeoJSON field storing a line of longitude and latitude coordinates.
The data is represented as:
{'type' : 'LineString' ,
'coordinates' : [[x1, y1], [x1, y1] ... [xn, yn]]}
You can either pass a dict with the full information or a list of points.
Requires mongodb >= 2.4
New in version 0.8.
| Parameters: | auto_index (bool) – Automatically create a ‘2dsphere’ index. Defaults to True. |
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mongoengine.fields.PolygonField(auto_index=True, *args, **kwargs)¶A GeoJSON field storing a polygon of longitude and latitude coordinates.
The data is represented as:
{'type' : 'Polygon' ,
'coordinates' : [[[x1, y1], [x1, y1] ... [xn, yn]],
[[x1, y1], [x1, y1] ... [xn, yn]]}
You can either pass a dict with the full information or a list of LineStrings. The first LineString being the outside and the rest being holes.
Requires mongodb >= 2.4
New in version 0.8.
| Parameters: | auto_index (bool) – Automatically create a ‘2dsphere’ index. Defaults to True. |
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mongoengine.fields.MultiPointField(auto_index=True, *args, **kwargs)¶A GeoJSON field storing a list of Points.
The data is represented as:
{'type' : 'MultiPoint' ,
'coordinates' : [[x1, y1], [x2, y2]]}
You can either pass a dict with the full information or a list to set the value.
Requires mongodb >= 2.6
New in version 0.9.
| Parameters: | auto_index (bool) – Automatically create a ‘2dsphere’ index. Defaults to True. |
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mongoengine.fields.MultiLineStringField(auto_index=True, *args, **kwargs)¶A GeoJSON field storing a list of LineStrings.
The data is represented as:
{'type' : 'MultiLineString' ,
'coordinates' : [[[x1, y1], [x1, y1] ... [xn, yn]],
[[x1, y1], [x1, y1] ... [xn, yn]]]}
You can either pass a dict with the full information or a list of points.
Requires mongodb >= 2.6
New in version 0.9.
| Parameters: | auto_index (bool) – Automatically create a ‘2dsphere’ index. Defaults to True. |
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mongoengine.fields.MultiPolygonField(auto_index=True, *args, **kwargs)¶A GeoJSON field storing list of Polygons.
The data is represented as:
{'type' : 'MultiPolygon' ,
'coordinates' : [[
[[x1, y1], [x1, y1] ... [xn, yn]],
[[x1, y1], [x1, y1] ... [xn, yn]]
], [
[[x1, y1], [x1, y1] ... [xn, yn]],
[[x1, y1], [x1, y1] ... [xn, yn]]
]
}
You can either pass a dict with the full information or a list of Polygons.
Requires mongodb >= 2.6
New in version 0.9.
| Parameters: | auto_index (bool) – Automatically create a ‘2dsphere’ index. Defaults to True. |
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mongoengine.fields.GridFSError¶mongoengine.fields.GridFSProxy(grid_id=None, key=None, instance=None, db_alias='default', collection_name='fs')¶Proxy object to handle writing and reading of files to and from GridFS
New in version 0.4.
Changed in version 0.5: - added optional size param to read
Changed in version 0.6: - added collection name param
mongoengine.fields.ImageGridFsProxy(grid_id=None, key=None, instance=None, db_alias='default', collection_name='fs')¶Proxy for ImageField
versionadded: 0.6
mongoengine.fields.ImproperlyConfigured¶New in version 0.9.
Additional queries for Embedded Documents are available when using the
EmbeddedDocumentListField to store a list of embedded
documents.
A list of embedded documents is returned as a special list with the following methods:
mongoengine.base.datastructures.EmbeddedDocumentList(list_items, instance, name)¶count()¶The number of embedded documents in the list.
| Returns: | The length of the list, equivalent to the result of len(). |
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create(**values)¶Creates a new embedded document and saves it to the database.
Note
The embedded document changes are not automatically saved to the database after calling this method.
| Parameters: | values – A dictionary of values for the embedded document. |
|---|---|
| Returns: | The new embedded document instance. |
delete()¶Deletes the embedded documents from the database.
Note
The embedded document changes are not automatically saved to the database after calling this method.
| Returns: | The number of entries deleted. |
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exclude(**kwargs)¶Filters the list by excluding embedded documents with the given keyword arguments.
| Parameters: | kwargs – The keyword arguments corresponding to the fields to exclude on. Multiple arguments are treated as if they are ANDed together. |
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| Returns: | A new EmbeddedDocumentList containing the non-matching
embedded documents. |
Raises AttributeError if a given keyword is not a valid field for
the embedded document class.
filter(**kwargs)¶Filters the list by only including embedded documents with the given keyword arguments.
| Parameters: | kwargs – The keyword arguments corresponding to the fields to filter on. Multiple arguments are treated as if they are ANDed together. |
|---|---|
| Returns: | A new EmbeddedDocumentList containing the matching
embedded documents. |
Raises AttributeError if a given keyword is not a valid field for
the embedded document class.
first()¶Return the first embedded document in the list, or None
if empty.
get(**kwargs)¶Retrieves an embedded document determined by the given keyword arguments.
| Parameters: | kwargs – The keyword arguments corresponding to the fields to search on. Multiple arguments are treated as if they are ANDed together. |
|---|---|
| Returns: | The embedded document matched by the given keyword arguments. |
Raises DoesNotExist if the arguments used to query an embedded
document returns no results. MultipleObjectsReturned if more
than one result is returned.
save(*args, **kwargs)¶Saves the ancestor document.
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update(**update)¶Updates the embedded documents with the given update values.
Note
The embedded document changes are not automatically saved to the database after calling this method.
| Parameters: | update – A dictionary of update values to apply to each embedded document. |
|---|---|
| Returns: | The number of entries updated. |
mongoengine.common._import_class(cls_name)¶Cache mechanism for imports.
Due to complications of circular imports mongoengine needs to do lots of inline imports in functions. This is inefficient as classes are imported repeated throughout the mongoengine code. This is compounded by some recursive functions requiring inline imports.
mongoengine.common provides a single point to import all these
classes. Circular imports aren’t an issue as it dynamically imports the
class when first needed. Subsequent calls to the
_import_class() can then directly retrieve the
class from the mongoengine.common._class_registry_cache.