Bump version to 0.15.0

Add LazyReferenceField & GenericLazyReferencField

.install_mongodb_on_travis.sh

@@ -1,5 +1,6 @@
 #!/bin/bash
 
+sudo apt-get remove mongodb-org-server
 sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 7F0CEB10
 
 if [ "$MONGODB" = "2.4" ]; then
@@ -13,7 +14,7 @@ elif [ "$MONGODB" = "2.6" ]; then
     sudo apt-get install mongodb-org-server=2.6.12
     # service should be started automatically
 elif [ "$MONGODB" = "3.0" ]; then
-    echo "deb http://repo.mongodb.org/apt/ubuntu precise/mongodb-org/3.0 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb.list
+    echo "deb http://repo.mongodb.org/apt/ubuntu trusty/mongodb-org/3.0 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb.list
     sudo apt-get update
     sudo apt-get install mongodb-org-server=3.0.14
     # service should be started automatically
@@ -21,3 +22,6 @@ else
     echo "Invalid MongoDB version, expected 2.4, 2.6, or 3.0."
     exit 1
 fi;
+
+mkdir db
+1>db/logs mongod --dbpath=db &

.travis.yml

@@ -15,6 +15,7 @@ language: python
 python:
 - 2.7
 - 3.5
+- 3.6
 - pypy
 
 env:
@@ -39,9 +40,15 @@ matrix:
     env: MONGODB=2.4 PYMONGO=3.0
   - python: 3.5
     env: MONGODB=3.0 PYMONGO=3.0
+  - python: 3.6
+    env: MONGODB=2.4 PYMONGO=3.0
+  - python: 3.6
+    env: MONGODB=3.0 PYMONGO=3.0
 
 before_install:
 - bash .install_mongodb_on_travis.sh
+- sleep 15  # https://docs.travis-ci.com/user/database-setup/#MongoDB-does-not-immediately-accept-connections
+- mongo --eval 'db.version();'
 
 install:
 - sudo apt-get install python-dev python3-dev libopenjpeg-dev zlib1g-dev libjpeg-turbo8-dev
@@ -90,7 +97,7 @@ deploy:
   distributions: "sdist bdist_wheel"
 
   # only deploy on tagged commits (aka GitHub releases) and only for the
-  # parent repo's builds running Python 2.7 along with dev PyMongo (we run
+  # parent repo's builds running Python 2.7 along with PyMongo v3.0 (we run
   # Travis against many different Python and PyMongo versions and we don't
   # want the deploy to occur multiple times).
   on:

AUTHORS

@@ -243,3 +243,5 @@ that much better:
  * Victor Varvaryuk
  * Stanislav Kaledin (https://github.com/sallyruthstruik)
  * Dmitry Yantsen (https://github.com/mrTable)
+ * Renjianxin (https://github.com/Davidrjx)
+ * Erdenezul Batmunkh (https://github.com/erdenezul)

docs/changelog.rst

@@ -2,9 +2,17 @@
 Changelog
 =========
 
-Development
-===========
-- (Fill this out as you fix issues and develop your features).
+Changes in 0.15.0
+=================
+- Add LazyReferenceField and GenericLazyReferenceField to address #1230
+
+Changes in 0.14.1
+=================
+- Removed SemiStrictDict and started using a regular dict for `BaseDocument._data` #1630
+- Added support for the `$position` param in the `$push` operator #1566
+- Fixed `DateTimeField` interpreting an empty string as today #1533
+- Added a missing `__ne__` method to the `GridFSProxy` class #1632
+- Fixed `BaseQuerySet._fields_to_db_fields` #1553
 
 Changes in 0.14.0
 =================

docs/guide/querying.rst

@@ -565,6 +565,15 @@ cannot use the `$` syntax in keyword arguments it has been mapped to `S`::
     >>> post.tags
     ['database', 'mongodb']
 
+From MongoDB version 2.6, push operator supports $position value which allows
+to push values with index.
+    >>> post = BlogPost(title="Test", tags=["mongo"])
+    >>> post.save()
+    >>> post.update(push__tags__0=["database", "code"])
+    >>> post.reload()
+    >>> post.tags
+    ['database', 'code', 'mongo']
+
 .. note::
     Currently only top level lists are handled, future versions of mongodb /
     pymongo plan to support nested positional operators.  See `The $ positional

mongoengine/__init__.py

@@ -23,7 +23,7 @@ __all__ = (list(document.__all__) + list(fields.__all__) +
            list(signals.__all__) + list(errors.__all__))
 
 
-VERSION = (0, 14, 0)
+VERSION = (0, 15, 0)
 
 
 def get_version():

mongoengine/base/__init__.py

@@ -15,7 +15,7 @@ __all__ = (
     'UPDATE_OPERATORS', '_document_registry', 'get_document',
 
     # datastructures
-    'BaseDict', 'BaseList', 'EmbeddedDocumentList',
+    'BaseDict', 'BaseList', 'EmbeddedDocumentList', 'LazyReference',
 
     # document
     'BaseDocument',

mongoengine/base/datastructures.py

@@ -1,12 +1,13 @@
 import itertools
 import weakref
 
+from bson import DBRef
 import six
 
 from mongoengine.common import _import_class
 from mongoengine.errors import DoesNotExist, MultipleObjectsReturned
 
-__all__ = ('BaseDict', 'BaseList', 'EmbeddedDocumentList')
+__all__ = ('BaseDict', 'BaseList', 'EmbeddedDocumentList', 'LazyReference')
 
 
 class BaseDict(dict):
@@ -127,7 +128,7 @@ class BaseList(list):
         return value
 
     def __iter__(self):
-        for i in xrange(self.__len__()):
+        for i in six.moves.range(self.__len__()):
             yield self[i]
 
     def __setitem__(self, key, value, *args, **kwargs):
@@ -447,40 +448,40 @@ class StrictDict(object):
         return cls._classes[allowed_keys]
 
 
-class SemiStrictDict(StrictDict):
-    __slots__ = ('_extras', )
-    _classes = {}
+class LazyReference(DBRef):
+    __slots__ = ('_cached_doc', 'passthrough', 'document_type')
 
-    def __getattr__(self, attr):
-        try:
-            super(SemiStrictDict, self).__getattr__(attr)
-        except AttributeError:
-            try:
-                return self.__getattribute__('_extras')[attr]
-            except KeyError as e:
-                raise AttributeError(e)
+    def fetch(self, force=False):
+        if not self._cached_doc or force:
+            self._cached_doc = self.document_type.objects.get(pk=self.pk)
+            if not self._cached_doc:
+                raise DoesNotExist('Trying to dereference unknown document %s' % (self))
+        return self._cached_doc
 
-    def __setattr__(self, attr, value):
-        try:
-            super(SemiStrictDict, self).__setattr__(attr, value)
-        except AttributeError:
-            try:
-                self._extras[attr] = value
-            except AttributeError:
-                self._extras = {attr: value}
+    @property
+    def pk(self):
+        return self.id
 
-    def __delattr__(self, attr):
-        try:
-            super(SemiStrictDict, self).__delattr__(attr)
-        except AttributeError:
-            try:
-                del self._extras[attr]
-            except KeyError as e:
-                raise AttributeError(e)
+    def __init__(self, document_type, pk, cached_doc=None, passthrough=False):
+        self.document_type = document_type
+        self._cached_doc = cached_doc
+        self.passthrough = passthrough
+        super(LazyReference, self).__init__(self.document_type._get_collection_name(), pk)
 
-    def __iter__(self):
+    def __getitem__(self, name):
+        if not self.passthrough:
+            raise KeyError()
+        document = self.fetch()
+        return document[name]
+
+    def __getattr__(self, name):
+        if not object.__getattribute__(self, 'passthrough'):
+            raise AttributeError()
+        document = self.fetch()
         try:
-            extras_iter = iter(self.__getattribute__('_extras'))
-        except AttributeError:
-            extras_iter = ()
-        return itertools.chain(super(SemiStrictDict, self).__iter__(), extras_iter)
+            return document[name]
+        except KeyError:
+            raise AttributeError()
+
+    def __repr__(self):
+        return "<LazyReference(%s, %r)>" % (self.document_type, self.pk)

mongoengine/base/document.py

@@ -13,13 +13,13 @@ from mongoengine import signals
 from mongoengine.base.common import get_document
 from mongoengine.base.datastructures import (BaseDict, BaseList,
                                              EmbeddedDocumentList,
-                                             SemiStrictDict, StrictDict)
+                                             StrictDict)
 from mongoengine.base.fields import ComplexBaseField
 from mongoengine.common import _import_class
 from mongoengine.errors import (FieldDoesNotExist, InvalidDocumentError,
                                 LookUpError, OperationError, ValidationError)
 
-__all__ = ('BaseDocument',)
+__all__ = ('BaseDocument', 'NON_FIELD_ERRORS')
 
 NON_FIELD_ERRORS = '__all__'
 
@@ -79,8 +79,7 @@ class BaseDocument(object):
         if self.STRICT and not self._dynamic:
             self._data = StrictDict.create(allowed_keys=self._fields_ordered)()
         else:
-            self._data = SemiStrictDict.create(
-                allowed_keys=self._fields_ordered)()
+            self._data = {}
 
         self._dynamic_fields = SON()
 

mongoengine/connection.py

@@ -146,13 +146,14 @@ def get_connection(alias=DEFAULT_CONNECTION_NAME, reconnect=False):
         raise MongoEngineConnectionError(msg)
 
     def _clean_settings(settings_dict):
-        irrelevant_fields = set([
-            'name', 'username', 'password', 'authentication_source',
-            'authentication_mechanism'
-        ])
+        # set literal more efficient than calling set function
+        irrelevant_fields_set = {
+            'name', 'username', 'password',
+            'authentication_source', 'authentication_mechanism'
+        }
         return {
             k: v for k, v in settings_dict.items()
-            if k not in irrelevant_fields
+            if k not in irrelevant_fields_set
         }
 
     # Retrieve a copy of the connection settings associated with the requested

mongoengine/document.py

@@ -320,7 +320,7 @@ class Document(BaseDocument):
         :param save_condition: only perform save if matching record in db
             satisfies condition(s) (e.g. version number).
             Raises :class:`OperationError` if the conditions are not satisfied
-        :parm signal_kwargs: (optional) kwargs dictionary to be passed to
+        :param signal_kwargs: (optional) kwargs dictionary to be passed to
             the signal calls.
 
         .. versionchanged:: 0.5

mongoengine/fields.py

@@ -26,7 +26,8 @@ except ImportError:
     Int64 = long
 
 from mongoengine.base import (BaseDocument, BaseField, ComplexBaseField,
-                              GeoJsonBaseField, ObjectIdField, get_document)
+                              GeoJsonBaseField, LazyReference, ObjectIdField,
+                              get_document)
 from mongoengine.connection import DEFAULT_CONNECTION_NAME, get_db
 from mongoengine.document import Document, EmbeddedDocument
 from mongoengine.errors import DoesNotExist, InvalidQueryError, ValidationError
@@ -46,6 +47,7 @@ __all__ = (
     'GenericEmbeddedDocumentField', 'DynamicField', 'ListField',
     'SortedListField', 'EmbeddedDocumentListField', 'DictField',
     'MapField', 'ReferenceField', 'CachedReferenceField',
+    'LazyReferenceField', 'GenericLazyReferenceField',
     'GenericReferenceField', 'BinaryField', 'GridFSError', 'GridFSProxy',
     'FileField', 'ImageGridFsProxy', 'ImproperlyConfigured', 'ImageField',
     'GeoPointField', 'PointField', 'LineStringField', 'PolygonField',
@@ -483,6 +485,10 @@ class DateTimeField(BaseField):
         if not isinstance(value, six.string_types):
             return None
 
+        value = value.strip()
+        if not value:
+            return None
+
         # Attempt to parse a datetime:
         if dateutil:
             try:
@@ -949,6 +955,15 @@ class ReferenceField(BaseField):
     """A reference to a document that will be automatically dereferenced on
     access (lazily).
 
+    Note this means you will get a database I/O access everytime you access
+    this field. This is necessary because the field returns a :class:`~mongoengine.Document`
+    which precise type can depend of the value of the `_cls` field present in the
+    document in database.
+    In short, using this type of field can lead to poor performances (especially
+    if you access this field only to retrieve it `pk` field which is already
+    known before dereference). To solve this you should consider using the
+    :class:`~mongoengine.fields.LazyReferenceField`.
+
     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`
@@ -1083,8 +1098,8 @@ class ReferenceField(BaseField):
 
     def validate(self, value):
 
-        if not isinstance(value, (self.document_type, DBRef, ObjectId)):
-            self.error('A ReferenceField only accepts DBRef, ObjectId or documents')
+        if not isinstance(value, (self.document_type, LazyReference, DBRef, ObjectId)):
+            self.error('A ReferenceField only accepts DBRef, LazyReference, ObjectId or documents')
 
         if isinstance(value, Document) and value.id is None:
             self.error('You can only reference documents once they have been '
@@ -1259,6 +1274,12 @@ class GenericReferenceField(BaseField):
     """A reference to *any* :class:`~mongoengine.document.Document` subclass
     that will be automatically dereferenced on access (lazily).
 
+    Note this field works the same way as :class:`~mongoengine.document.ReferenceField`,
+    doing database I/O access the first time it is accessed (even if it's to access
+    it ``pk`` or ``id`` field).
+    To solve this you should consider using the
+    :class:`~mongoengine.fields.GenericLazyReferenceField`.
+
     .. note ::
         * Any documents used as a generic reference must be registered in the
           document registry.  Importing the model will automatically register
@@ -1461,6 +1482,9 @@ class GridFSProxy(object):
         else:
             return False
 
+    def __ne__(self, other):
+        return not self == other
+
     @property
     def fs(self):
         if not self._fs:
@@ -2134,3 +2158,189 @@ class MultiPolygonField(GeoJsonBaseField):
     .. versionadded:: 0.9
     """
     _type = 'MultiPolygon'
+
+
+class LazyReferenceField(BaseField):
+    """A really lazy reference to a document.
+    Unlike the :class:`~mongoengine.fields.ReferenceField` it must be manually
+    dereferenced using it ``fetch()`` method.
+
+    .. versionadded:: 0.15
+    """
+
+    def __init__(self, document_type, passthrough=False, dbref=False,
+                 reverse_delete_rule=DO_NOTHING, **kwargs):
+        """Initialises the Reference Field.
+
+        :param dbref:  Store the reference as :class:`~pymongo.dbref.DBRef`
+          or as the :class:`~pymongo.objectid.ObjectId`.id .
+        :param reverse_delete_rule: Determines what to do when the referring
+          object is deleted
+        :param passthrough: When trying to access unknown fields, the
+        :class:`~mongoengine.base.datastructure.LazyReference` instance will
+        automatically call `fetch()` and try to retrive the field on the fetched
+        document. Note this only work getting field (not setting or deleting).
+        """
+        if (
+            not isinstance(document_type, six.string_types) and
+            not issubclass(document_type, Document)
+        ):
+            self.error('Argument to LazyReferenceField constructor must be a '
+                       'document class or a string')
+
+        self.dbref = dbref
+        self.passthrough = passthrough
+        self.document_type_obj = document_type
+        self.reverse_delete_rule = reverse_delete_rule
+        super(LazyReferenceField, self).__init__(**kwargs)
+
+    @property
+    def document_type(self):
+        if isinstance(self.document_type_obj, six.string_types):
+            if self.document_type_obj == RECURSIVE_REFERENCE_CONSTANT:
+                self.document_type_obj = self.owner_document
+            else:
+                self.document_type_obj = get_document(self.document_type_obj)
+        return self.document_type_obj
+
+    def __get__(self, instance, owner):
+        """Descriptor to allow lazy dereferencing."""
+        if instance is None:
+            # Document class being used rather than a document object
+            return self
+
+        value = instance._data.get(self.name)
+        if isinstance(value, LazyReference):
+            if value.passthrough != self.passthrough:
+                instance._data[self.name] = LazyReference(
+                    value.document_type, value.pk, passthrough=self.passthrough)
+        elif value is not None:
+            if isinstance(value, self.document_type):
+                value = LazyReference(self.document_type, value.pk, passthrough=self.passthrough)
+            elif isinstance(value, DBRef):
+                value = LazyReference(self.document_type, value.id, passthrough=self.passthrough)
+            else:
+                # value is the primary key of the referenced document
+                value = LazyReference(self.document_type, value, passthrough=self.passthrough)
+            instance._data[self.name] = value
+
+        return super(LazyReferenceField, self).__get__(instance, owner)
+
+    def to_mongo(self, value):
+        if isinstance(value, LazyReference):
+            pk = value.pk
+        elif isinstance(value, self.document_type):
+            pk = value.pk
+        elif isinstance(value, DBRef):
+            pk = value.id
+        else:
+            # value is the primary key of the referenced document
+            pk = value
+        id_field_name = self.document_type._meta['id_field']
+        id_field = self.document_type._fields[id_field_name]
+        pk = id_field.to_mongo(pk)
+        if self.dbref:
+            return DBRef(self.document_type._get_collection_name(), pk)
+        else:
+            return pk
+
+    def validate(self, value):
+        if isinstance(value, LazyReference):
+            if not issubclass(value.document_type, self.document_type):
+                self.error('Reference must be on a `%s` document.' % self.document_type)
+            pk = value.pk
+        elif isinstance(value, self.document_type):
+            pk = value.pk
+        elif isinstance(value, DBRef):
+            # TODO: check collection ?
+            collection = self.document_type._get_collection_name()
+            if value.collection != collection:
+                self.error("DBRef on bad collection (must be on `%s`)" % collection)
+            pk = value.id
+        else:
+            # value is the primary key of the referenced document
+            id_field_name = self.document_type._meta['id_field']
+            id_field = getattr(self.document_type, id_field_name)
+            pk = value
+            try:
+                id_field.validate(pk)
+            except ValidationError:
+                self.error(
+                    "value should be `{0}` document, LazyReference or DBRef on `{0}` "
+                    "or `{0}`'s primary key (i.e. `{1}`)".format(
+                        self.document_type.__name__, type(id_field).__name__))
+
+        if pk is None:
+            self.error('You can only reference documents once they have been '
+                       'saved to the database')
+
+    def prepare_query_value(self, op, value):
+        if value is None:
+            return None
+        super(LazyReferenceField, self).prepare_query_value(op, value)
+        return self.to_mongo(value)
+
+    def lookup_member(self, member_name):
+        return self.document_type._fields.get(member_name)
+
+
+class GenericLazyReferenceField(GenericReferenceField):
+    """A reference to *any* :class:`~mongoengine.document.Document` subclass
+    that will be automatically dereferenced on access (lazily).
+    Unlike the :class:`~mongoengine.fields.GenericReferenceField` it must be
+    manually dereferenced using it ``fetch()`` method.
+
+    .. note ::
+        * Any documents used as a generic reference must be registered in the
+          document registry.  Importing the model will automatically register
+          it.
+
+        * You can use the choices param to limit the acceptable Document types
+
+    .. versionadded:: 0.15
+    """
+
+    def __init__(self, *args, **kwargs):
+        self.passthrough = kwargs.pop('passthrough', False)
+        super(GenericLazyReferenceField, self).__init__(*args, **kwargs)
+
+    def _validate_choices(self, value):
+        if isinstance(value, LazyReference):
+            value = value.document_type
+        super(GenericLazyReferenceField, self)._validate_choices(value)
+
+    def __get__(self, instance, owner):
+        if instance is None:
+            return self
+
+        value = instance._data.get(self.name)
+        if isinstance(value, LazyReference):
+            if value.passthrough != self.passthrough:
+                instance._data[self.name] = LazyReference(
+                    value.document_type, value.pk, passthrough=self.passthrough)
+        elif value is not None:
+            if isinstance(value, (dict, SON)):
+                value = LazyReference(get_document(value['_cls']), value['_ref'].id, passthrough=self.passthrough)
+            elif isinstance(value, Document):
+                value = LazyReference(type(value), value.pk, passthrough=self.passthrough)
+            instance._data[self.name] = value
+
+        return super(GenericLazyReferenceField, self).__get__(instance, owner)
+
+    def validate(self, value):
+        if isinstance(value, LazyReference) and value.pk is None:
+            self.error('You can only reference documents once they have been'
+                       ' saved to the database')
+        return super(GenericLazyReferenceField, self).validate(value)
+
+    def to_mongo(self, document):
+        if document is None:
+            return None
+
+        if isinstance(document, LazyReference):
+            return SON((
+                ('_cls', document.document_type._class_name),
+                ('_ref', document)
+            ))
+        else:
+            return super(GenericLazyReferenceField, self).to_mongo(document)

mongoengine/queryset/base.py

@@ -1722,25 +1722,33 @@ class BaseQuerySet(object):
         return frequencies
 
     def _fields_to_dbfields(self, fields):
-        """Translate fields paths to its db equivalents"""
-        ret = []
+        """Translate fields' paths to their db equivalents."""
         subclasses = []
-        document = self._document
-        if document._meta['allow_inheritance']:
+        if self._document._meta['allow_inheritance']:
             subclasses = [get_document(x)
-                          for x in document._subclasses][1:]
+                          for x in self._document._subclasses][1:]
+
+        db_field_paths = []
         for field in fields:
+            field_parts = field.split('.')
             try:
-                field = '.'.join(f.db_field for f in
-                                 document._lookup_field(field.split('.')))
-                ret.append(field)
+                field = '.'.join(
+                    f if isinstance(f, six.string_types) else f.db_field
+                    for f in self._document._lookup_field(field_parts)
+                )
+                db_field_paths.append(field)
             except LookUpError as err:
                 found = False
+
+                # If a field path wasn't found on the main document, go
+                # through its subclasses and see if it exists on any of them.
                 for subdoc in subclasses:
                     try:
-                        subfield = '.'.join(f.db_field for f in
-                                            subdoc._lookup_field(field.split('.')))
-                        ret.append(subfield)
+                        subfield = '.'.join(
+                            f if isinstance(f, six.string_types) else f.db_field
+                            for f in subdoc._lookup_field(field_parts)
+                        )
+                        db_field_paths.append(subfield)
                         found = True
                         break
                     except LookUpError:
@@ -1748,7 +1756,8 @@ class BaseQuerySet(object):
 
                 if not found:
                     raise err
-        return ret
+
+        return db_field_paths
 
     def _get_order_by(self, keys):
         """Given a list of MongoEngine-style sort keys, return a list

mongoengine/queryset/queryset.py

@@ -1,3 +1,5 @@
+import six
+
 from mongoengine.errors import OperationError
 from mongoengine.queryset.base import (BaseQuerySet, CASCADE, DENY, DO_NOTHING,
                                        NULLIFY, PULL)
@@ -112,7 +114,7 @@ class QuerySet(BaseQuerySet):
         # Pull in ITER_CHUNK_SIZE docs from the database and store them in
         # the result cache.
         try:
-            for _ in xrange(ITER_CHUNK_SIZE):
+            for _ in six.moves.range(ITER_CHUNK_SIZE):
                 self._result_cache.append(self.next())
         except StopIteration:
             # Getting this exception means there are no more docs in the
@@ -166,7 +168,7 @@ class QuerySetNoCache(BaseQuerySet):
             return '.. queryset mid-iteration ..'
 
         data = []
-        for _ in xrange(REPR_OUTPUT_SIZE + 1):
+        for _ in six.moves.range(REPR_OUTPUT_SIZE + 1):
             try:
                 data.append(self.next())
             except StopIteration:

mongoengine/queryset/transform.py

@@ -284,7 +284,9 @@ def update(_doc_cls=None, **update):
             if isinstance(field, GeoJsonBaseField):
                 value = field.to_mongo(value)
 
-            if op in (None, 'set', 'push', 'pull'):
+            if op == 'push' and isinstance(value, (list, tuple, set)):
+                value = [field.prepare_query_value(op, v) for v in value]
+            elif op in (None, 'set', 'push', 'pull'):
                 if field.required or value is not None:
                     value = field.prepare_query_value(op, value)
             elif op in ('pushAll', 'pullAll'):
@@ -333,10 +335,22 @@ def update(_doc_cls=None, **update):
                 value = {key: value}
         elif op == 'addToSet' and isinstance(value, list):
             value = {key: {'$each': value}}
+        elif op == 'push':
+            if parts[-1].isdigit():
+                key = parts[0]
+                position = int(parts[-1])
+                # $position expects an iterable. If pushing a single value,
+                # wrap it in a list.
+                if not isinstance(value, (set, tuple, list)):
+                    value = [value]
+                value = {key: {'$each': value, '$position': position}}
+            elif isinstance(value, list):
+                value = {key: {'$each': value}}
+            else:
+                value = {key: value}
         else:
             value = {key: value}
         key = '$' + op
-
         if key not in mongo_update:
             mongo_update[key] = value
         elif key in mongo_update and isinstance(mongo_update[key], dict):

setup.py

@@ -70,9 +70,9 @@ setup(
     name='mongoengine',
     version=VERSION,
     author='Harry Marr',
-    author_email='harry.marr@{nospam}gmail.com',
-    maintainer="Ross Lawley",
-    maintainer_email="ross.lawley@{nospam}gmail.com",
+    author_email='harry.marr@gmail.com',
+    maintainer="Stefan Wojcik",
+    maintainer_email="wojcikstefan@gmail.com",
     url='http://mongoengine.org/',
     download_url='https://github.com/MongoEngine/mongoengine/tarball/master',
     license='MIT',

tests/document/instance.py

@@ -22,6 +22,8 @@ from mongoengine.queryset import NULLIFY, Q
 from mongoengine.context_managers import switch_db, query_counter
 from mongoengine import signals
 
+from tests.utils import needs_mongodb_v26
+
 TEST_IMAGE_PATH = os.path.join(os.path.dirname(__file__),
                                '../fields/mongoengine.png')
 
@@ -826,6 +828,22 @@ class InstanceTest(unittest.TestCase):
 
         self.assertDbEqual([dict(other_doc.to_mongo()), dict(doc.to_mongo())])
 
+    @needs_mongodb_v26
+    def test_modify_with_positional_push(self):
+        class BlogPost(Document):
+            tags = ListField(StringField())
+
+        post = BlogPost.objects.create(tags=['python'])
+        self.assertEqual(post.tags, ['python'])
+        post.modify(push__tags__0=['code', 'mongo'])
+        self.assertEqual(post.tags, ['code', 'mongo', 'python'])
+
+        # Assert same order of the list items is maintained in the db
+        self.assertEqual(
+            BlogPost._get_collection().find_one({'_id': post.pk})['tags'],
+            ['code', 'mongo', 'python']
+        )
+
     def test_save(self):
         """Ensure that a document may be saved in the database."""
 
@@ -3149,6 +3167,22 @@ class InstanceTest(unittest.TestCase):
 
         person.update(set__height=2.0)
 
+    @needs_mongodb_v26
+    def test_push_with_position(self):
+        """Ensure that push with position works properly for an instance."""
+        class BlogPost(Document):
+            slug = StringField()
+            tags = ListField(StringField())
+
+        blog = BlogPost()
+        blog.slug = "ABC"
+        blog.tags = ["python"]
+        blog.save()
+
+        blog.update(push__tags__0=["mongodb", "code"])
+        blog.reload()
+        self.assertEqual(blog.tags, ['mongodb', 'code', 'python'])
+
 
 if __name__ == '__main__':
     unittest.main()

tests/fields/fields.py

@@ -26,7 +26,7 @@ except ImportError:
 from mongoengine import *
 from mongoengine.connection import get_db
 from mongoengine.base import (BaseDict, BaseField, EmbeddedDocumentList,
-                              _document_registry)
+                              _document_registry, LazyReference)
 
 from tests.utils import MongoDBTestCase
 
@@ -35,6 +35,28 @@ __all__ = ("FieldTest", "EmbeddedDocumentListFieldTestCase")
 
 class FieldTest(MongoDBTestCase):
 
+    def test_datetime_from_empty_string(self):
+        """
+        Ensure an exception is raised when trying to
+        cast an empty string to datetime.
+        """
+        class MyDoc(Document):
+            dt = DateTimeField()
+
+        md = MyDoc(dt='')
+        self.assertRaises(ValidationError, md.save)
+
+    def test_datetime_from_whitespace_string(self):
+        """
+        Ensure an exception is raised when trying to
+        cast a whitespace-only string to datetime.
+        """
+        class MyDoc(Document):
+            dt = DateTimeField()
+
+        md = MyDoc(dt='   ')
+        self.assertRaises(ValidationError, md.save)
+
     def test_default_values_nothing_set(self):
         """Ensure that default field values are used when creating
         a document.
@@ -909,7 +931,9 @@ class FieldTest(MongoDBTestCase):
             comments = ListField(EmbeddedDocumentField(Comment))
             tags = ListField(StringField())
             authors = ListField(ReferenceField(User))
+            authors_as_lazy = ListField(LazyReferenceField(User))
             generic = ListField(GenericReferenceField())
+            generic_as_lazy = ListField(GenericLazyReferenceField())
 
         User.drop_collection()
         BlogPost.drop_collection()
@@ -947,6 +971,15 @@ class FieldTest(MongoDBTestCase):
         post.authors = [user]
         post.validate()
 
+        post.authors_as_lazy = [Comment()]
+        self.assertRaises(ValidationError, post.validate)
+
+        post.authors_as_lazy = [User()]
+        self.assertRaises(ValidationError, post.validate)
+
+        post.authors_as_lazy = [user]
+        post.validate()
+
         post.generic = [1, 2]
         self.assertRaises(ValidationError, post.validate)
 
@@ -959,6 +992,18 @@ class FieldTest(MongoDBTestCase):
         post.generic = [user]
         post.validate()
 
+        post.generic_as_lazy = [1, 2]
+        self.assertRaises(ValidationError, post.validate)
+
+        post.generic_as_lazy = [User(), Comment()]
+        self.assertRaises(ValidationError, post.validate)
+
+        post.generic_as_lazy = [Comment()]
+        self.assertRaises(ValidationError, post.validate)
+
+        post.generic_as_lazy = [user]
+        post.validate()
+
     def test_sorted_list_sorting(self):
         """Ensure that a sorted list field properly sorts values.
         """
@@ -4576,5 +4621,436 @@ class CachedReferenceFieldTest(MongoDBTestCase):
         self.assertTrue(isinstance(ocorrence.animal, Animal))
 
 
+class LazyReferenceFieldTest(MongoDBTestCase):
+    def test_lazy_reference_config(self):
+        # Make sure ReferenceField only accepts a document class or a string
+        # with a document class name.
+        self.assertRaises(ValidationError, LazyReferenceField, EmbeddedDocument)
+
+    def test_lazy_reference_simple(self):
+        class Animal(Document):
+            name = StringField()
+            tag = StringField()
+
+        class Ocurrence(Document):
+            person = StringField()
+            animal = LazyReferenceField(Animal)
+
+        Animal.drop_collection()
+        Ocurrence.drop_collection()
+
+        animal = Animal(name="Leopard", tag="heavy").save()
+        Ocurrence(person="test", animal=animal).save()
+        p = Ocurrence.objects.get()
+        self.assertIsInstance(p.animal, LazyReference)
+        fetched_animal = p.animal.fetch()
+        self.assertEqual(fetched_animal, animal)
+        # `fetch` keep cache on referenced document by default...
+        animal.tag = "not so heavy"
+        animal.save()
+        double_fetch = p.animal.fetch()
+        self.assertIs(fetched_animal, double_fetch)
+        self.assertEqual(double_fetch.tag, "heavy")
+        # ...unless specified otherwise
+        fetch_force = p.animal.fetch(force=True)
+        self.assertIsNot(fetch_force, fetched_animal)
+        self.assertEqual(fetch_force.tag, "not so heavy")
+
+    def test_lazy_reference_fetch_invalid_ref(self):
+        class Animal(Document):
+            name = StringField()
+            tag = StringField()
+
+        class Ocurrence(Document):
+            person = StringField()
+            animal = LazyReferenceField(Animal)
+
+        Animal.drop_collection()
+        Ocurrence.drop_collection()
+
+        animal = Animal(name="Leopard", tag="heavy").save()
+        Ocurrence(person="test", animal=animal).save()
+        animal.delete()
+        p = Ocurrence.objects.get()
+        self.assertIsInstance(p.animal, LazyReference)
+        with self.assertRaises(DoesNotExist):
+            p.animal.fetch()
+
+    def test_lazy_reference_set(self):
+        class Animal(Document):
+            meta = {'allow_inheritance': True}
+
+            name = StringField()
+            tag = StringField()
+
+        class Ocurrence(Document):
+            person = StringField()
+            animal = LazyReferenceField(Animal)
+
+        Animal.drop_collection()
+        Ocurrence.drop_collection()
+
+        class SubAnimal(Animal):
+            nick = StringField()
+
+        animal = Animal(name="Leopard", tag="heavy").save()
+        sub_animal = SubAnimal(nick='doggo', name='dog').save()
+        for ref in (
+                animal,
+                animal.pk,
+                DBRef(animal._get_collection_name(), animal.pk),
+                LazyReference(Animal, animal.pk),
+
+                sub_animal,
+                sub_animal.pk,
+                DBRef(sub_animal._get_collection_name(), sub_animal.pk),
+                LazyReference(SubAnimal, sub_animal.pk),
+                ):
+            p = Ocurrence(person="test", animal=ref).save()
+            p.reload()
+            self.assertIsInstance(p.animal, LazyReference)
+            p.animal.fetch()
+
+    def test_lazy_reference_bad_set(self):
+        class Animal(Document):
+            name = StringField()
+            tag = StringField()
+
+        class Ocurrence(Document):
+            person = StringField()
+            animal = LazyReferenceField(Animal)
+
+        Animal.drop_collection()
+        Ocurrence.drop_collection()
+
+        class BadDoc(Document):
+            pass
+
+        animal = Animal(name="Leopard", tag="heavy").save()
+        baddoc = BadDoc().save()
+        for bad in (
+                42,
+                'foo',
+                baddoc,
+                DBRef(baddoc._get_collection_name(), animal.pk),
+                LazyReference(BadDoc, animal.pk)
+                ):
+            with self.assertRaises(ValidationError):
+                p = Ocurrence(person="test", animal=bad).save()
+
+    def test_lazy_reference_query_conversion(self):
+        """Ensure that LazyReferenceFields can be queried using objects and values
+        of the type of the primary key of the referenced object.
+        """
+        class Member(Document):
+            user_num = IntField(primary_key=True)
+
+        class BlogPost(Document):
+            title = StringField()
+            author = LazyReferenceField(Member, dbref=False)
+
+        Member.drop_collection()
+        BlogPost.drop_collection()
+
+        m1 = Member(user_num=1)
+        m1.save()
+        m2 = Member(user_num=2)
+        m2.save()
+
+        post1 = BlogPost(title='post 1', author=m1)
+        post1.save()
+
+        post2 = BlogPost(title='post 2', author=m2)
+        post2.save()
+
+        post = BlogPost.objects(author=m1).first()
+        self.assertEqual(post.id, post1.id)
+
+        post = BlogPost.objects(author=m2).first()
+        self.assertEqual(post.id, post2.id)
+
+        # Same thing by passing a LazyReference instance
+        post = BlogPost.objects(author=LazyReference(Member, m2.pk)).first()
+        self.assertEqual(post.id, post2.id)
+
+    def test_lazy_reference_query_conversion_dbref(self):
+        """Ensure that LazyReferenceFields can be queried using objects and values
+        of the type of the primary key of the referenced object.
+        """
+        class Member(Document):
+            user_num = IntField(primary_key=True)
+
+        class BlogPost(Document):
+            title = StringField()
+            author = LazyReferenceField(Member, dbref=True)
+
+        Member.drop_collection()
+        BlogPost.drop_collection()
+
+        m1 = Member(user_num=1)
+        m1.save()
+        m2 = Member(user_num=2)
+        m2.save()
+
+        post1 = BlogPost(title='post 1', author=m1)
+        post1.save()
+
+        post2 = BlogPost(title='post 2', author=m2)
+        post2.save()
+
+        post = BlogPost.objects(author=m1).first()
+        self.assertEqual(post.id, post1.id)
+
+        post = BlogPost.objects(author=m2).first()
+        self.assertEqual(post.id, post2.id)
+
+        # Same thing by passing a LazyReference instance
+        post = BlogPost.objects(author=LazyReference(Member, m2.pk)).first()
+        self.assertEqual(post.id, post2.id)
+
+    def test_lazy_reference_passthrough(self):
+        class Animal(Document):
+            name = StringField()
+            tag = StringField()
+
+        class Ocurrence(Document):
+            animal = LazyReferenceField(Animal, passthrough=False)
+            animal_passthrough = LazyReferenceField(Animal, passthrough=True)
+
+        Animal.drop_collection()
+        Ocurrence.drop_collection()
+
+        animal = Animal(name="Leopard", tag="heavy").save()
+        Ocurrence(animal=animal, animal_passthrough=animal).save()
+        p = Ocurrence.objects.get()
+        self.assertIsInstance(p.animal, LazyReference)
+        with self.assertRaises(KeyError):
+            p.animal['name']
+        with self.assertRaises(AttributeError):
+            p.animal.name
+        self.assertEqual(p.animal.pk, animal.pk)
+
+        self.assertEqual(p.animal_passthrough.name, "Leopard")
+        self.assertEqual(p.animal_passthrough['name'], "Leopard")
+
+        # Should not be able to access referenced document's methods
+        with self.assertRaises(AttributeError):
+            p.animal.save
+        with self.assertRaises(KeyError):
+            p.animal['save']
+
+    def test_lazy_reference_not_set(self):
+        class Animal(Document):
+            name = StringField()
+            tag = StringField()
+
+        class Ocurrence(Document):
+            person = StringField()
+            animal = LazyReferenceField(Animal)
+
+        Animal.drop_collection()
+        Ocurrence.drop_collection()
+
+        Ocurrence(person='foo').save()
+        p = Ocurrence.objects.get()
+        self.assertIs(p.animal, None)
+
+    def test_lazy_reference_equality(self):
+        class Animal(Document):
+            name = StringField()
+            tag = StringField()
+
+        Animal.drop_collection()
+
+        animal = Animal(name="Leopard", tag="heavy").save()
+        animalref = LazyReference(Animal, animal.pk)
+        self.assertEqual(animal, animalref)
+        self.assertEqual(animalref, animal)
+
+        other_animalref = LazyReference(Animal, ObjectId("54495ad94c934721ede76f90"))
+        self.assertNotEqual(animal, other_animalref)
+        self.assertNotEqual(other_animalref, animal)
+
+
+class GenericLazyReferenceFieldTest(MongoDBTestCase):
+    def test_generic_lazy_reference_simple(self):
+        class Animal(Document):
+            name = StringField()
+            tag = StringField()
+
+        class Ocurrence(Document):
+            person = StringField()
+            animal = GenericLazyReferenceField()
+
+        Animal.drop_collection()
+        Ocurrence.drop_collection()
+
+        animal = Animal(name="Leopard", tag="heavy").save()
+        Ocurrence(person="test", animal=animal).save()
+        p = Ocurrence.objects.get()
+        self.assertIsInstance(p.animal, LazyReference)
+        fetched_animal = p.animal.fetch()
+        self.assertEqual(fetched_animal, animal)
+        # `fetch` keep cache on referenced document by default...
+        animal.tag = "not so heavy"
+        animal.save()
+        double_fetch = p.animal.fetch()
+        self.assertIs(fetched_animal, double_fetch)
+        self.assertEqual(double_fetch.tag, "heavy")
+        # ...unless specified otherwise
+        fetch_force = p.animal.fetch(force=True)
+        self.assertIsNot(fetch_force, fetched_animal)
+        self.assertEqual(fetch_force.tag, "not so heavy")
+
+    def test_generic_lazy_reference_choices(self):
+        class Animal(Document):
+            name = StringField()
+
+        class Vegetal(Document):
+            name = StringField()
+
+        class Mineral(Document):
+            name = StringField()
+
+        class Ocurrence(Document):
+            living_thing = GenericLazyReferenceField(choices=[Animal, Vegetal])
+            thing = GenericLazyReferenceField()
+
+        Animal.drop_collection()
+        Vegetal.drop_collection()
+        Mineral.drop_collection()
+        Ocurrence.drop_collection()
+
+        animal = Animal(name="Leopard").save()
+        vegetal = Vegetal(name="Oak").save()
+        mineral = Mineral(name="Granite").save()
+
+        occ_animal = Ocurrence(living_thing=animal, thing=animal).save()
+        occ_vegetal = Ocurrence(living_thing=vegetal, thing=vegetal).save()
+        with self.assertRaises(ValidationError):
+            Ocurrence(living_thing=mineral).save()
+
+        occ = Ocurrence.objects.get(living_thing=animal)
+        self.assertEqual(occ, occ_animal)
+        self.assertIsInstance(occ.thing, LazyReference)
+        self.assertIsInstance(occ.living_thing, LazyReference)
+
+        occ.thing = vegetal
+        occ.living_thing = vegetal
+        occ.save()
+
+        occ.thing = mineral
+        occ.living_thing = mineral
+        with self.assertRaises(ValidationError):
+            occ.save()
+
+    def test_generic_lazy_reference_set(self):
+        class Animal(Document):
+            meta = {'allow_inheritance': True}
+
+            name = StringField()
+            tag = StringField()
+
+        class Ocurrence(Document):
+            person = StringField()
+            animal = GenericLazyReferenceField()
+
+        Animal.drop_collection()
+        Ocurrence.drop_collection()
+
+        class SubAnimal(Animal):
+            nick = StringField()
+
+        animal = Animal(name="Leopard", tag="heavy").save()
+        sub_animal = SubAnimal(nick='doggo', name='dog').save()
+        for ref in (
+                animal,
+                LazyReference(Animal, animal.pk),
+                {'_cls': 'Animal', '_ref': DBRef(animal._get_collection_name(), animal.pk)},
+
+                sub_animal,
+                LazyReference(SubAnimal, sub_animal.pk),
+                {'_cls': 'SubAnimal', '_ref': DBRef(sub_animal._get_collection_name(), sub_animal.pk)},
+                ):
+            p = Ocurrence(person="test", animal=ref).save()
+            p.reload()
+            self.assertIsInstance(p.animal, (LazyReference, Document))
+            p.animal.fetch()
+
+    def test_generic_lazy_reference_bad_set(self):
+        class Animal(Document):
+            name = StringField()
+            tag = StringField()
+
+        class Ocurrence(Document):
+            person = StringField()
+            animal = GenericLazyReferenceField(choices=['Animal'])
+
+        Animal.drop_collection()
+        Ocurrence.drop_collection()
+
+        class BadDoc(Document):
+            pass
+
+        animal = Animal(name="Leopard", tag="heavy").save()
+        baddoc = BadDoc().save()
+        for bad in (
+                42,
+                'foo',
+                baddoc,
+                LazyReference(BadDoc, animal.pk)
+                ):
+            with self.assertRaises(ValidationError):
+                p = Ocurrence(person="test", animal=bad).save()
+
+    def test_generic_lazy_reference_query_conversion(self):
+        class Member(Document):
+            user_num = IntField(primary_key=True)
+
+        class BlogPost(Document):
+            title = StringField()
+            author = GenericLazyReferenceField()
+
+        Member.drop_collection()
+        BlogPost.drop_collection()
+
+        m1 = Member(user_num=1)
+        m1.save()
+        m2 = Member(user_num=2)
+        m2.save()
+
+        post1 = BlogPost(title='post 1', author=m1)
+        post1.save()
+
+        post2 = BlogPost(title='post 2', author=m2)
+        post2.save()
+
+        post = BlogPost.objects(author=m1).first()
+        self.assertEqual(post.id, post1.id)
+
+        post = BlogPost.objects(author=m2).first()
+        self.assertEqual(post.id, post2.id)
+
+        # Same thing by passing a LazyReference instance
+        post = BlogPost.objects(author=LazyReference(Member, m2.pk)).first()
+        self.assertEqual(post.id, post2.id)
+
+    def test_generic_lazy_reference_not_set(self):
+        class Animal(Document):
+            name = StringField()
+            tag = StringField()
+
+        class Ocurrence(Document):
+            person = StringField()
+            animal = GenericLazyReferenceField()
+
+        Animal.drop_collection()
+        Ocurrence.drop_collection()
+
+        Ocurrence(person='foo').save()
+        p = Ocurrence.objects.get()
+        self.assertIs(p.animal, None)
+
+
 if __name__ == '__main__':
     unittest.main()

tests/queryset/field_list.py

@@ -197,14 +197,18 @@ class OnlyExcludeAllTest(unittest.TestCase):
             title = StringField()
             text = StringField()
 
+        class VariousData(EmbeddedDocument):
+            some = BooleanField()
+
         class BlogPost(Document):
             content = StringField()
             author = EmbeddedDocumentField(User)
             comments = ListField(EmbeddedDocumentField(Comment))
+            various = MapField(field=EmbeddedDocumentField(VariousData))
 
         BlogPost.drop_collection()
 
-        post = BlogPost(content='Had a good coffee today...')
+        post = BlogPost(content='Had a good coffee today...', various={'test_dynamic':{'some': True}})
         post.author = User(name='Test User')
         post.comments = [Comment(title='I aggree', text='Great post!'), Comment(title='Coffee', text='I hate coffee')]
         post.save()
@@ -215,6 +219,9 @@ class OnlyExcludeAllTest(unittest.TestCase):
         self.assertEqual(obj.author.name, 'Test User')
         self.assertEqual(obj.comments, [])
 
+        obj = BlogPost.objects.only('various.test_dynamic.some').get()
+        self.assertEqual(obj.various["test_dynamic"].some, True)
+
         obj = BlogPost.objects.only('content', 'comments.title',).get()
         self.assertEqual(obj.content, 'Had a good coffee today...')
         self.assertEqual(obj.author, None)

tests/queryset/geo.py

@@ -510,6 +510,24 @@ class GeoQueriesTest(MongoDBTestCase):
         roads = Road.objects.filter(poly__geo_intersects={"$geometry": polygon}).count()
         self.assertEqual(1, roads)
 
+    def test_aspymongo_with_only(self):
+        """Ensure as_pymongo works with only"""
+        class Place(Document):
+            location = PointField()
+
+        Place.drop_collection()
+        p = Place(location=[24.946861267089844, 60.16311983618494])
+        p.save()
+        qs = Place.objects().only('location')
+        self.assertDictEqual(
+            qs.as_pymongo()[0]['location'],
+            {u'type': u'Point',
+             u'coordinates': [
+                24.946861267089844,
+                60.16311983618494]
+            }
+        )
+
     def test_2dsphere_point_sets_correctly(self):
         class Location(Document):
             loc = PointField()

tests/queryset/modify.py

@@ -1,6 +1,8 @@
 import unittest
 
-from mongoengine import connect, Document, IntField
+from mongoengine import connect, Document, IntField, StringField, ListField
+
+from tests.utils import needs_mongodb_v26
 
 __all__ = ("FindAndModifyTest",)
 
@@ -94,6 +96,37 @@ class FindAndModifyTest(unittest.TestCase):
         self.assertEqual(old_doc.to_mongo(), {"_id": 1})
         self.assertDbEqual([{"_id": 0, "value": 0}, {"_id": 1, "value": -1}])
 
+    @needs_mongodb_v26
+    def test_modify_with_push(self):
+        class BlogPost(Document):
+            tags = ListField(StringField())
+
+        BlogPost.drop_collection()
+
+        blog = BlogPost.objects.create()
+
+        # Push a new tag via modify with new=False (default).
+        BlogPost(id=blog.id).modify(push__tags='code')
+        self.assertEqual(blog.tags, [])
+        blog.reload()
+        self.assertEqual(blog.tags, ['code'])
+
+        # Push a new tag via modify with new=True.
+        blog = BlogPost.objects(id=blog.id).modify(push__tags='java', new=True)
+        self.assertEqual(blog.tags, ['code', 'java'])
+
+        # Push a new tag with a positional argument.
+        blog = BlogPost.objects(id=blog.id).modify(
+            push__tags__0='python',
+            new=True)
+        self.assertEqual(blog.tags, ['python', 'code', 'java'])
+
+        # Push multiple new tags with a positional argument.
+        blog = BlogPost.objects(id=blog.id).modify(
+            push__tags__1=['go', 'rust'],
+            new=True)
+        self.assertEqual(blog.tags, ['python', 'go', 'rust', 'code', 'java'])
+
 
 if __name__ == '__main__':
     unittest.main()

tests/queryset/queryset.py

@@ -1903,6 +1903,32 @@ class QuerySetTest(unittest.TestCase):
 
         BlogPost.drop_collection()
 
+    @needs_mongodb_v26
+    def test_update_push_with_position(self):
+        """Ensure that the 'push' update with position works properly.
+        """
+        class BlogPost(Document):
+            slug = StringField()
+            tags = ListField(StringField())
+
+        BlogPost.drop_collection()
+
+        post = BlogPost.objects.create(slug="test")
+
+        BlogPost.objects.filter(id=post.id).update(push__tags="code")
+        BlogPost.objects.filter(id=post.id).update(push__tags__0=["mongodb", "python"])
+        post.reload()
+        self.assertEqual(post.tags, ['mongodb', 'python', 'code'])
+
+        BlogPost.objects.filter(id=post.id).update(set__tags__2="java")
+        post.reload()
+        self.assertEqual(post.tags, ['mongodb', 'python', 'java'])
+
+        #test push with singular value
+        BlogPost.objects.filter(id=post.id).update(push__tags__0='scala')
+        post.reload()
+        self.assertEqual(post.tags, ['scala', 'mongodb', 'python', 'java'])
+
     def test_update_push_and_pull_add_to_set(self):
         """Ensure that the 'pull' update operation works correctly.
         """

tests/test_datastructures.py

@@ -1,6 +1,6 @@
 import unittest
 
-from mongoengine.base.datastructures import StrictDict, SemiStrictDict
+from mongoengine.base.datastructures import StrictDict
 
 
 class TestStrictDict(unittest.TestCase):
@@ -76,44 +76,5 @@ class TestStrictDict(unittest.TestCase):
         assert dict(**d) == {'a': 1, 'b': 2}
 
 
-class TestSemiSrictDict(TestStrictDict):
-    def strict_dict_class(self, *args, **kwargs):
-        return SemiStrictDict.create(*args, **kwargs)
-
-    def test_init_fails_on_nonexisting_attrs(self):
-        # disable irrelevant test
-        pass
-
-    def test_setattr_raises_on_nonexisting_attr(self):
-        # disable irrelevant test
-        pass
-
-    def test_setattr_getattr_nonexisting_attr_succeeds(self):
-        d = self.dtype()
-        d.x = 1
-        self.assertEqual(d.x, 1)
-
-    def test_init_succeeds_with_nonexisting_attrs(self):
-        d = self.dtype(a=1, b=1, c=1, x=2)
-        self.assertEqual((d.a, d.b, d.c, d.x), (1, 1, 1, 2))
-
-    def test_iter_with_nonexisting_attrs(self):
-        d = self.dtype(a=1, b=1, c=1, x=2)
-        self.assertEqual(list(d), ['a', 'b', 'c', 'x'])
-
-    def test_iteritems_with_nonexisting_attrs(self):
-        d = self.dtype(a=1, b=1, c=1, x=2)
-        self.assertEqual(list(d.iteritems()), [('a', 1), ('b', 1), ('c', 1), ('x', 2)])
-
-    def tets_cmp_with_strict_dicts(self):
-        d = self.dtype(a=1, b=1, c=1)
-        dd = StrictDict.create(("a", "b", "c"))(a=1, b=1, c=1)
-        self.assertEqual(d, dd)
-
-    def test_cmp_with_strict_dict_with_nonexisting_attrs(self):
-        d = self.dtype(a=1, b=1, c=1, x=2)
-        dd = StrictDict.create(("a", "b", "c", "x"))(a=1, b=1, c=1, x=2)
-        self.assertEqual(d, dd)
-
 if __name__ == '__main__':
     unittest.main()