cleanup BaseQuerySet.__getitem__

.gitignore

@@ -17,3 +17,4 @@ tests/test_bugfix.py
 htmlcov/
 venv
 venv3
+scratchpad

docs/guide/connecting.rst

@@ -42,13 +42,18 @@ the :attr:`host` to
     will establish connection to ``production`` database using
     ``admin`` username and ``qwerty`` password.
 
-ReplicaSets
+Replica Sets
-===========
+============
 
-MongoEngine supports
+MongoEngine supports connecting to replica sets::
-:class:`~pymongo.mongo_replica_set_client.MongoReplicaSetClient`. To use them,
+
-please use an URI style connection and provide the ``replicaSet`` name
+    from mongoengine import connect
-in the connection kwargs.
+
+    # Regular connect
+    connect('dbname', replicaset='rs-name')
+
+    # MongoDB URI-style connect
+    connect(host='mongodb://localhost/dbname?replicaSet=rs-name')
 
 Read preferences are supported through the connection or via individual
 queries by passing the read_preference ::
@@ -59,76 +64,74 @@ queries by passing the read_preference ::
 Multiple Databases
 ==================
 
-Multiple database support was added in MongoEngine 0.6. To use multiple
+To use multiple databases you can use :func:`~mongoengine.connect` and provide
-databases you can use :func:`~mongoengine.connect` and provide an `alias` name
+an `alias` name for the connection - if no `alias` is provided then "default"
-for the connection - if no `alias` is provided then "default" is used.
+is used.
 
 In the background this uses :func:`~mongoengine.register_connection` to
 store the data and you can register all aliases up front if required.
 
 Individual documents can also support multiple databases by providing a
-`db_alias` in their meta data.  This allows :class:`~pymongo.dbref.DBRef` objects
+`db_alias` in their meta data. This allows :class:`~pymongo.dbref.DBRef`
-to point across databases and collections.  Below is an example schema, using
+objects to point across databases and collections. Below is an example schema,
-3 different databases to store data::
+using 3 different databases to store data::
 
         class User(Document):
             name = StringField()
 
-            meta = {"db_alias": "user-db"}
+            meta = {'db_alias': 'user-db'}
 
         class Book(Document):
             name = StringField()
 
-            meta = {"db_alias": "book-db"}
+            meta = {'db_alias': 'book-db'}
 
         class AuthorBooks(Document):
             author = ReferenceField(User)
             book = ReferenceField(Book)
 
-            meta = {"db_alias": "users-books-db"}
+            meta = {'db_alias': 'users-books-db'}
 
 
 Context Managers
 ================
-Sometimes you may want to switch the database or collection to query against
+Sometimes you may want to switch the database or collection to query against.
-for a class.
 For example, archiving older data into a separate database for performance
 reasons or writing functions that dynamically choose collections to write
-document to.
+a document to.
 
 Switch Database
 ---------------
 The :class:`~mongoengine.context_managers.switch_db` context manager allows
 you to change the database alias for a given class allowing quick and easy
-access the same User document across databases::
+access to the same User document across databases::
 
     from mongoengine.context_managers import switch_db
 
     class User(Document):
         name = StringField()
 
-        meta = {"db_alias": "user-db"}
+        meta = {'db_alias': 'user-db'}
 
     with switch_db(User, 'archive-user-db') as User:
-        User(name="Ross").save()  # Saves the 'archive-user-db'
+        User(name='Ross').save()  # Saves the 'archive-user-db'
 
 
 Switch Collection
 -----------------
 The :class:`~mongoengine.context_managers.switch_collection` context manager
 allows you to change the collection for a given class allowing quick and easy
-access the same Group document across collection::
+access to the same Group document across collection::
 
         from mongoengine.context_managers import switch_collection
 
         class Group(Document):
             name = StringField()
 
-        Group(name="test").save()  # Saves in the default db
+        Group(name='test').save()  # Saves in the default db
 
         with switch_collection(Group, 'group2000') as Group:
-            Group(name="hello Group 2000 collection!").save()  # Saves in group2000 collection
+            Group(name='hello Group 2000 collection!').save()  # Saves in group2000 collection
-
 
 
 .. note:: Make sure any aliases have been registered with

docs/guide/installing.rst

@@ -2,13 +2,13 @@
 Installing MongoEngine
 ======================
 
-To use MongoEngine, you will need to download `MongoDB <http://mongodb.org/>`_
+To use MongoEngine, you will need to download `MongoDB <http://mongodb.com/>`_
 and ensure it is running in an accessible location. You will also need
 `PyMongo <http://api.mongodb.org/python>`_ to use MongoEngine, but if you
 install MongoEngine using setuptools, then the dependencies will be handled for
 you.
 
-MongoEngine is available on PyPI, so to use it you can use :program:`pip`:
+MongoEngine is available on PyPI, so you can use :program:`pip`:
 
 .. code-block:: console
 

docs/guide/querying.rst

@@ -340,14 +340,19 @@ Javascript code that is executed on the database server.
 
 Counting results
 ----------------
-Just as with limiting and skipping results, there is a method on
+Just as with limiting and skipping results, there is a method on a
-:class:`~mongoengine.queryset.QuerySet` objects --
+:class:`~mongoengine.queryset.QuerySet` object --
-:meth:`~mongoengine.queryset.QuerySet.count`, but there is also a more Pythonic
+:meth:`~mongoengine.queryset.QuerySet.count`::
-way of achieving this::
 
-    num_users = len(User.objects)
+    num_users = User.objects.count()
 
-Even if len() is the Pythonic way of counting results, keep in mind that if you concerned about performance, :meth:`~mongoengine.queryset.QuerySet.count` is the way to go since it only execute a server side count query, while len() retrieves the results, places them in cache, and finally counts them. If we compare the performance of the two operations, len() is much slower than :meth:`~mongoengine.queryset.QuerySet.count`.
+You could technically use ``len(User.objects)`` to get the same result, but it
+would be significantly slower than :meth:`~mongoengine.queryset.QuerySet.count`.
+When you execute a server-side count query, you let MongoDB do the heavy
+lifting and you receive a single integer over the wire. Meanwhile, len()
+retrieves all the results, places them in a local cache, and finally counts
+them. If we compare the performance of the two operations, len() is much slower
+than :meth:`~mongoengine.queryset.QuerySet.count`.
 
 Further aggregation
 -------------------

docs/tutorial.rst

@@ -3,11 +3,10 @@ Tutorial
 ========
 
 This tutorial introduces **MongoEngine** by means of example --- we will walk
-through how to create a simple **Tumblelog** application. A Tumblelog is a type
+through how to create a simple **Tumblelog** application. A tumblelog is a
-of blog where posts are not constrained to being conventional text-based posts.
+blog that supports mixed media content, including text, images, links, video,
-As well as text-based entries, users may post images, links, videos, etc. For
+audio, etc. For simplicity's sake, we'll stick to text, image, and link
-simplicity's sake, we'll stick to text, image and link entries in our
+entries. As the purpose of this tutorial is to introduce MongoEngine, we'll
-application. As the purpose of this tutorial is to introduce MongoEngine, we'll
 focus on the data-modelling side of the application, leaving out a user
 interface.
 
@@ -16,14 +15,14 @@ Getting started
 
 Before we start, make sure that a copy of MongoDB is running in an accessible
 location --- running it locally will be easier, but if that is not an option
-then it may be run on a remote server. If you haven't installed mongoengine,
+then it may be run on a remote server. If you haven't installed MongoEngine,
 simply use pip to install it like so::
 
     $ pip install mongoengine
 
 Before we can start using MongoEngine, we need to tell it how to connect to our
 instance of :program:`mongod`. For this we use the :func:`~mongoengine.connect`
-function. If running locally the only argument we need to provide is the name
+function. If running locally, the only argument we need to provide is the name
 of the MongoDB database to use::
 
     from mongoengine import *
@@ -39,8 +38,8 @@ Defining our documents
 MongoDB is *schemaless*, which means that no schema is enforced by the database
 --- we may add and remove fields however we want and MongoDB won't complain.
 This makes life a lot easier in many regards, especially when there is a change
-to the data model. However, defining schemata for our documents can help to
+to the data model. However, defining schemas for our documents can help to iron
-iron out bugs involving incorrect types or missing fields, and also allow us to
+out bugs involving incorrect types or missing fields, and also allow us to
 define utility methods on our documents in the same way that traditional
 :abbr:`ORMs (Object-Relational Mappers)` do.
 
@@ -96,7 +95,7 @@ using* the new fields we need to support video posts. This fits with the
 Object-Oriented principle of *inheritance* nicely. We can think of
 :class:`Post` as a base class, and :class:`TextPost`, :class:`ImagePost` and
 :class:`LinkPost` as subclasses of :class:`Post`. In fact, MongoEngine supports
-this kind of modelling out of the box --- all you need do is turn on inheritance
+this kind of modeling out of the box --- all you need do is turn on inheritance
 by setting :attr:`allow_inheritance` to True in the :attr:`meta`::
 
     class Post(Document):
@@ -128,8 +127,8 @@ link table, we can just store a list of tags in each post. So, for both
 efficiency and simplicity's sake, we'll store the tags as strings directly
 within the post, rather than storing references to tags in a separate
 collection. Especially as tags are generally very short (often even shorter
-than a document's id), this denormalisation won't impact very strongly on the
+than a document's id), this denormalization won't impact the size of the
-size of our database. So let's take a look that the code our modified
+database very strongly. Let's take a look at the code of our modified
 :class:`Post` class::
 
     class Post(Document):
@@ -141,7 +140,7 @@ The :class:`~mongoengine.fields.ListField` object that is used to define a Post'
 takes a field object as its first argument --- this means that you can have
 lists of any type of field (including lists).
 
-.. note:: We don't need to modify the specialised post types as they all
+.. note:: We don't need to modify the specialized post types as they all
     inherit from :class:`Post`.
 
 Comments
@@ -149,7 +148,7 @@ Comments
 
 A comment is typically associated with *one* post. In a relational database, to
 display a post with its comments, we would have to retrieve the post from the
-database, then query the database again for the comments associated with the
+database and then query the database again for the comments associated with the
 post. This works, but there is no real reason to be storing the comments
 separately from their associated posts, other than to work around the
 relational model. Using MongoDB we can store the comments as a list of
@@ -219,8 +218,8 @@ Now that we've got our user in the database, let's add a couple of posts::
     post2.tags = ['mongoengine']
     post2.save()
 
-.. note:: If you change a field on a object that has already been saved, then
+.. note:: If you change a field on an object that has already been saved and
-    call :meth:`save` again, the document will be updated.
+    then call :meth:`save` again, the document will be updated.
 
 Accessing our data
 ==================
@@ -232,17 +231,17 @@ used to access the documents in the database collection associated with that
 class. So let's see how we can get our posts' titles::
 
     for post in Post.objects:
-        print post.title
+        print(post.title)
 
 Retrieving type-specific information
 ------------------------------------
 
-This will print the titles of our posts, one on each line. But What if we want
+This will print the titles of our posts, one on each line. But what if we want
 to access the type-specific data (link_url, content, etc.)? One way is simply
 to use the :attr:`objects` attribute of a subclass of :class:`Post`::
 
     for post in TextPost.objects:
-        print post.content
+        print(post.content)
 
 Using TextPost's :attr:`objects` attribute only returns documents that were
 created using :class:`TextPost`. Actually, there is a more general rule here:
@@ -259,16 +258,14 @@ instances of :class:`Post` --- they were instances of the subclass of
 practice::
 
     for post in Post.objects:
-        print post.title
+        print(post.title)
-        print '=' * len(post.title)
+        print('=' * len(post.title))
 
         if isinstance(post, TextPost):
-            print post.content
+            print(post.content)
 
         if isinstance(post, LinkPost):
-            print 'Link:', post.link_url
+            print('Link: {}'.format(post.link_url))
-
-        print
 
 This would print the title of each post, followed by the content if it was a
 text post, and "Link: <url>" if it was a link post.
@@ -283,7 +280,7 @@ your query.  Let's adjust our query so that only posts with the tag "mongodb"
 are returned::
 
     for post in Post.objects(tags='mongodb'):
-        print post.title
+        print(post.title)
 
 There are also methods available on :class:`~mongoengine.queryset.QuerySet`
 objects that allow different results to be returned, for example, calling
@@ -292,11 +289,11 @@ the first matched by the query you provide. Aggregation functions may also be
 used on :class:`~mongoengine.queryset.QuerySet` objects::
 
     num_posts = Post.objects(tags='mongodb').count()
-    print 'Found %d posts with tag "mongodb"' % num_posts
+    print('Found {} posts with tag "mongodb"'.format(num_posts))
 
-Learning more about mongoengine
+Learning more about MongoEngine
 -------------------------------
 
 If you got this far you've made a great start, so well done! The next step on
-your mongoengine journey is the `full user guide <guide/index.html>`_, where you
+your MongoEngine journey is the `full user guide <guide/index.html>`_, where
-can learn indepth about how to use mongoengine and mongodb.
+you can learn in-depth about how to use MongoEngine and MongoDB.

mongoengine/queryset/base.py

@@ -158,44 +158,49 @@ class BaseQuerySet(object):
         # self._cursor
 
     def __getitem__(self, key):
-        """Support skip and limit using getitem and slicing syntax."""
+        """Return a document instance corresponding to a given index if
+        the key is an integer. If the key is a slice, translate its
+        bounds into a skip and a limit, and return a cloned queryset
+        with that skip/limit applied. For example:
+
+        >>> User.objects[0]
+        <User: User object>
+        >>> User.objects[1:3]
+        [<User: User object>, <User: User object>]
+        """
         queryset = self.clone()
 
-        # Slice provided
+        # Handle a slice
         if isinstance(key, slice):
-            try:
             queryset._cursor_obj = queryset._cursor[key]
             queryset._skip, queryset._limit = key.start, key.stop
             if key.start and key.stop:
                 queryset._limit = key.stop - key.start
-            except IndexError as err:
+
-                # PyMongo raises an error if key.start == key.stop, catch it,
-                # bin it, kill it.
-                start = key.start or 0
-                if start >= 0 and key.stop >= 0 and key.step is None:
-                    if start == key.stop:
-                        queryset.limit(0)
-                        queryset._skip = key.start
-                        queryset._limit = key.stop - start
-                        return queryset
-                raise err
             # Allow further QuerySet modifications to be performed
             return queryset
-        # Integer index provided
+
+        # Handle an index
         elif isinstance(key, int):
             if queryset._scalar:
                 return queryset._get_scalar(
-                    queryset._document._from_son(queryset._cursor[key],
+                    queryset._document._from_son(
+                        queryset._cursor[key],
                         _auto_dereference=self._auto_dereference,
-                                                 only_fields=self.only_fields))
+                        only_fields=self.only_fields
+                    )
+                )
 
             if queryset._as_pymongo:
                 return queryset._get_as_pymongo(queryset._cursor[key])
-            return queryset._document._from_son(queryset._cursor[key],
-                                                _auto_dereference=self._auto_dereference,
-                                                only_fields=self.only_fields)
 
-        raise AttributeError
+            return queryset._document._from_son(
+                queryset._cursor[key],
+                _auto_dereference=self._auto_dereference,
+                only_fields=self.only_fields
+            )
+
+        raise AttributeError('Provide a slice or an integer index')
 
     def __iter__(self):
         raise NotImplementedError
@@ -286,7 +291,7 @@ class BaseQuerySet(object):
 
         .. versionadded:: 0.4
         """
-        return self._document(**kwargs).save()
+        return self._document(**kwargs).save(force_insert=True)
 
     def first(self):
         """Retrieve the first object matching the query."""

tests/document/indexes.py

@@ -412,7 +412,6 @@ class IndexesTest(unittest.TestCase):
         User.ensure_indexes()
         info = User.objects._collection.index_information()
         self.assertEqual(sorted(info.keys()), ['_cls_1_user_guid_1', '_id_'])
-        User.drop_collection()
 
     def test_embedded_document_index(self):
         """Tests settings an index on an embedded document
@@ -434,7 +433,6 @@ class IndexesTest(unittest.TestCase):
 
         info = BlogPost.objects._collection.index_information()
         self.assertEqual(sorted(info.keys()), ['_id_', 'date.yr_-1'])
-        BlogPost.drop_collection()
 
     def test_list_embedded_document_index(self):
         """Ensure list embedded documents can be indexed
@@ -461,7 +459,6 @@ class IndexesTest(unittest.TestCase):
         post1 = BlogPost(title="Embedded Indexes tests in place",
                          tags=[Tag(name="about"), Tag(name="time")])
         post1.save()
-        BlogPost.drop_collection()
 
     def test_recursive_embedded_objects_dont_break_indexes(self):
 
@@ -622,8 +619,6 @@ class IndexesTest(unittest.TestCase):
         post3 = BlogPost(title='test3', date=Date(year=2010), slug='test')
         self.assertRaises(OperationError, post3.save)
 
-        BlogPost.drop_collection()
-
     def test_unique_embedded_document(self):
         """Ensure that uniqueness constraints are applied to fields on embedded documents.
         """
@@ -651,8 +646,6 @@ class IndexesTest(unittest.TestCase):
                          sub=SubDocument(year=2010, slug='test'))
         self.assertRaises(NotUniqueError, post3.save)
 
-        BlogPost.drop_collection()
-
     def test_unique_embedded_document_in_list(self):
         """
         Ensure that the uniqueness constraints are applied to fields in
@@ -683,8 +676,6 @@ class IndexesTest(unittest.TestCase):
 
         self.assertRaises(NotUniqueError, post2.save)
 
-        BlogPost.drop_collection()
-
     def test_unique_with_embedded_document_and_embedded_unique(self):
         """Ensure that uniqueness constraints are applied to fields on
         embedded documents.  And work with unique_with as well.
@@ -718,8 +709,6 @@ class IndexesTest(unittest.TestCase):
                          sub=SubDocument(year=2009, slug='test-1'))
         self.assertRaises(NotUniqueError, post3.save)
 
-        BlogPost.drop_collection()
-
     def test_ttl_indexes(self):
 
         class Log(Document):
@@ -759,13 +748,11 @@ class IndexesTest(unittest.TestCase):
             raise AssertionError("We saved a dupe!")
         except NotUniqueError:
             pass
-        Customer.drop_collection()
 
     def test_unique_and_primary(self):
         """If you set a field as primary, then unexpected behaviour can occur.
         You won't create a duplicate but you will update an existing document.
         """
-
         class User(Document):
             name = StringField(primary_key=True, unique=True)
             password = StringField()
@@ -781,8 +768,23 @@ class IndexesTest(unittest.TestCase):
         self.assertEqual(User.objects.count(), 1)
         self.assertEqual(User.objects.get().password, 'secret2')
 
+    def test_unique_and_primary_create(self):
+        """Create a new record with a duplicate primary key
+        throws an exception
+        """
+        class User(Document):
+            name = StringField(primary_key=True)
+            password = StringField()
+
         User.drop_collection()
 
+        User.objects.create(name='huangz', password='secret')
+        with self.assertRaises(NotUniqueError):
+            User.objects.create(name='huangz', password='secret2')
+
+        self.assertEqual(User.objects.count(), 1)
+        self.assertEqual(User.objects.get().password, 'secret')
+
     def test_index_with_pk(self):
         """Ensure you can use `pk` as part of a query"""
 

tests/document/instance.py

@@ -28,8 +28,6 @@ TEST_IMAGE_PATH = os.path.join(os.path.dirname(__file__),
 __all__ = ("InstanceTest",)
 
 
-
-
 class InstanceTest(unittest.TestCase):
 
     def setUp(self):
@@ -72,8 +70,7 @@ class InstanceTest(unittest.TestCase):
             self.assertEqual(field._instance, instance)
 
     def test_capped_collection(self):
-        """Ensure that capped collections work properly.
+        """Ensure that capped collections work properly."""
-        """
         class Log(Document):
             date = DateTimeField(default=datetime.now)
             meta = {
@@ -181,8 +178,7 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual('<Article: привет мир>', repr(doc))
 
     def test_repr_none(self):
-        """Ensure None values handled correctly
+        """Ensure None values are handled correctly."""
-        """
         class Article(Document):
             title = StringField()
 
@@ -190,25 +186,23 @@ class InstanceTest(unittest.TestCase):
                 return None
 
         doc = Article(title=u'привет мир')
-
         self.assertEqual('<Article: None>', repr(doc))
 
     def test_queryset_resurrects_dropped_collection(self):
         self.Person.drop_collection()
-
         self.assertEqual([], list(self.Person.objects()))
 
+        # Ensure works correctly with inhertited classes
         class Actor(self.Person):
             pass
 
-        # Ensure works correctly with inhertited classes
         Actor.objects()
         self.Person.drop_collection()
         self.assertEqual([], list(Actor.objects()))
 
     def test_polymorphic_references(self):
-        """Ensure that the correct subclasses are returned from a query when
+        """Ensure that the correct subclasses are returned from a query
-        using references / generic references
+        when using references / generic references
         """
         class Animal(Document):
             meta = {'allow_inheritance': True}
@@ -258,9 +252,6 @@ class InstanceTest(unittest.TestCase):
         classes = [a.__class__ for a in Zoo.objects.first().animals]
         self.assertEqual(classes, [Animal, Fish, Mammal, Dog, Human])
 
-        Zoo.drop_collection()
-        Animal.drop_collection()
-
     def test_reference_inheritance(self):
         class Stats(Document):
             created = DateTimeField(default=datetime.now)
@@ -287,8 +278,7 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(list_stats, CompareStats.objects.first().stats)
 
     def test_db_field_load(self):
-        """Ensure we load data correctly
+        """Ensure we load data correctly from the right db field."""
-        """
         class Person(Document):
             name = StringField(required=True)
             _rank = StringField(required=False, db_field="rank")
@@ -307,8 +297,7 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(Person.objects.get(name="Fred").rank, "Private")
 
     def test_db_embedded_doc_field_load(self):
-        """Ensure we load embedded document data correctly
+        """Ensure we load embedded document data correctly."""
-        """
         class Rank(EmbeddedDocument):
             title = StringField(required=True)
 
@@ -333,8 +322,7 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(Person.objects.get(name="Fred").rank, "Private")
 
     def test_custom_id_field(self):
-        """Ensure that documents may be created with custom primary keys.
+        """Ensure that documents may be created with custom primary keys."""
-        """
         class User(Document):
             username = StringField(primary_key=True)
             name = StringField()
@@ -382,10 +370,7 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(user_son['_id'], 'mongo')
         self.assertTrue('username' not in user_son['_id'])
 
-        User.drop_collection()
-
     def test_document_not_registered(self):
-
         class Place(Document):
             name = StringField()
 
@@ -407,7 +392,6 @@ class InstanceTest(unittest.TestCase):
             list(Place.objects.all())
 
     def test_document_registry_regressions(self):
-
         class Location(Document):
             name = StringField()
             meta = {'allow_inheritance': True}
@@ -421,18 +405,16 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(Area, get_document("Location.Area"))
 
     def test_creation(self):
-        """Ensure that document may be created using keyword arguments.
+        """Ensure that document may be created using keyword arguments."""
-        """
         person = self.Person(name="Test User", age=30)
         self.assertEqual(person.name, "Test User")
         self.assertEqual(person.age, 30)
 
     def test_to_dbref(self):
-        """Ensure that you can get a dbref of a document"""
+        """Ensure that you can get a dbref of a document."""
         person = self.Person(name="Test User", age=30)
         self.assertRaises(OperationError, person.to_dbref)
         person.save()
-
         person.to_dbref()
 
     def test_save_abstract_document(self):
@@ -445,8 +427,7 @@ class InstanceTest(unittest.TestCase):
             Doc(name='aaa').save()
 
     def test_reload(self):
-        """Ensure that attributes may be reloaded.
+        """Ensure that attributes may be reloaded."""
-        """
         person = self.Person(name="Test User", age=20)
         person.save()
 
@@ -479,7 +460,6 @@ class InstanceTest(unittest.TestCase):
         doc = Animal(superphylum='Deuterostomia')
         doc.save()
         doc.reload()
-        Animal.drop_collection()
 
     def test_reload_sharded_nested(self):
         class SuperPhylum(EmbeddedDocument):
@@ -493,11 +473,9 @@ class InstanceTest(unittest.TestCase):
         doc = Animal(superphylum=SuperPhylum(name='Deuterostomia'))
         doc.save()
         doc.reload()
-        Animal.drop_collection()
 
     def test_reload_referencing(self):
-        """Ensures reloading updates weakrefs correctly
+        """Ensures reloading updates weakrefs correctly."""
-        """
         class Embedded(EmbeddedDocument):
             dict_field = DictField()
             list_field = ListField()
@@ -569,8 +547,7 @@ class InstanceTest(unittest.TestCase):
             self.assertFalse("Threw wrong exception")
 
     def test_reload_of_non_strict_with_special_field_name(self):
-        """Ensures reloading works for documents with meta strict == False
+        """Ensures reloading works for documents with meta strict == False."""
-        """
         class Post(Document):
             meta = {
                 'strict': False
@@ -591,8 +568,7 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(post.items, ["more lorem", "even more ipsum"])
 
     def test_dictionary_access(self):
-        """Ensure that dictionary-style field access works properly.
+        """Ensure that dictionary-style field access works properly."""
-        """
         person = self.Person(name='Test User', age=30, job=self.Job())
         self.assertEqual(person['name'], 'Test User')
 
@@ -634,8 +610,7 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(sub_doc.to_mongo().keys(), ['id'])
 
     def test_embedded_document(self):
-        """Ensure that embedded documents are set up correctly.
+        """Ensure that embedded documents are set up correctly."""
-        """
         class Comment(EmbeddedDocument):
             content = StringField()
 
@@ -643,8 +618,7 @@ class InstanceTest(unittest.TestCase):
         self.assertFalse('id' in Comment._fields)
 
     def test_embedded_document_instance(self):
-        """Ensure that embedded documents can reference parent instance
+        """Ensure that embedded documents can reference parent instance."""
-        """
         class Embedded(EmbeddedDocument):
             string = StringField()
 
@@ -652,6 +626,7 @@ class InstanceTest(unittest.TestCase):
             embedded_field = EmbeddedDocumentField(Embedded)
 
         Doc.drop_collection()
+
         doc = Doc(embedded_field=Embedded(string="Hi"))
         self.assertHasInstance(doc.embedded_field, doc)
 
@@ -661,7 +636,8 @@ class InstanceTest(unittest.TestCase):
 
     def test_embedded_document_complex_instance(self):
         """Ensure that embedded documents in complex fields can reference
-        parent instance"""
+        parent instance.
+        """
         class Embedded(EmbeddedDocument):
             string = StringField()
 
@@ -677,8 +653,7 @@ class InstanceTest(unittest.TestCase):
         self.assertHasInstance(doc.embedded_field[0], doc)
 
     def test_embedded_document_complex_instance_no_use_db_field(self):
-        """Ensure that use_db_field is propagated to list of Emb Docs
+        """Ensure that use_db_field is propagated to list of Emb Docs."""
-        """
         class Embedded(EmbeddedDocument):
             string = StringField(db_field='s')
 
@@ -690,7 +665,6 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(d['embedded_field'], [{'string': 'Hi'}])
 
     def test_instance_is_set_on_setattr(self):
-
         class Email(EmbeddedDocument):
             email = EmailField()
 
@@ -698,6 +672,7 @@ class InstanceTest(unittest.TestCase):
             email = EmbeddedDocumentField(Email)
 
         Account.drop_collection()
+
         acc = Account()
         acc.email = Email(email='test@example.com')
         self.assertHasInstance(acc._data["email"], acc)
@@ -707,7 +682,6 @@ class InstanceTest(unittest.TestCase):
         self.assertHasInstance(acc1._data["email"], acc1)
 
     def test_instance_is_set_on_setattr_on_embedded_document_list(self):
-
         class Email(EmbeddedDocument):
             email = EmailField()
 
@@ -853,32 +827,28 @@ class InstanceTest(unittest.TestCase):
         self.assertDbEqual([dict(other_doc.to_mongo()), dict(doc.to_mongo())])
 
     def test_save(self):
-        """Ensure that a document may be saved in the database.
+        """Ensure that a document may be saved in the database."""
-        """
+
         # Create person object and save it to the database
         person = self.Person(name='Test User', age=30)
         person.save()
+
         # Ensure that the object is in the database
         collection = self.db[self.Person._get_collection_name()]
         person_obj = collection.find_one({'name': 'Test User'})
         self.assertEqual(person_obj['name'], 'Test User')
         self.assertEqual(person_obj['age'], 30)
         self.assertEqual(person_obj['_id'], person.id)
-        # Test skipping validation on save
 
+        # Test skipping validation on save
         class Recipient(Document):
             email = EmailField(required=True)
 
         recipient = Recipient(email='root@localhost')
         self.assertRaises(ValidationError, recipient.save)
-
-        try:
         recipient.save(validate=False)
-        except ValidationError:
-            self.fail()
 
     def test_save_to_a_value_that_equates_to_false(self):
-
         class Thing(EmbeddedDocument):
             count = IntField()
 
@@ -898,7 +868,6 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(user.thing.count, 0)
 
     def test_save_max_recursion_not_hit(self):
-
         class Person(Document):
             name = StringField()
             parent = ReferenceField('self')
@@ -924,7 +893,6 @@ class InstanceTest(unittest.TestCase):
         p0.save()
 
     def test_save_max_recursion_not_hit_with_file_field(self):
-
         class Foo(Document):
             name = StringField()
             picture = FileField()
@@ -948,7 +916,6 @@ class InstanceTest(unittest.TestCase):
             self.assertEqual(b.picture, b.bar.picture, b.bar.bar.picture)
 
     def test_save_cascades(self):
-
         class Person(Document):
             name = StringField()
             parent = ReferenceField('self')
@@ -971,7 +938,6 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(p1.name, p.parent.name)
 
     def test_save_cascade_kwargs(self):
-
         class Person(Document):
             name = StringField()
             parent = ReferenceField('self')
@@ -992,7 +958,6 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(p1.name, p2.parent.name)
 
     def test_save_cascade_meta_false(self):
-
         class Person(Document):
             name = StringField()
             parent = ReferenceField('self')
@@ -1021,7 +986,6 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(p1.name, p.parent.name)
 
     def test_save_cascade_meta_true(self):
-
         class Person(Document):
             name = StringField()
             parent = ReferenceField('self')
@@ -1046,7 +1010,6 @@ class InstanceTest(unittest.TestCase):
         self.assertNotEqual(p1.name, p.parent.name)
 
     def test_save_cascades_generically(self):
-
         class Person(Document):
             name = StringField()
             parent = GenericReferenceField()
@@ -1072,7 +1035,6 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(p1.name, p.parent.name)
 
     def test_save_atomicity_condition(self):
-
         class Widget(Document):
             toggle = BooleanField(default=False)
             count = IntField(default=0)
@@ -1150,7 +1112,8 @@ class InstanceTest(unittest.TestCase):
 
     def test_update(self):
         """Ensure that an existing document is updated instead of be
-        overwritten."""
+        overwritten.
+        """
         # Create person object and save it to the database
         person = self.Person(name='Test User', age=30)
         person.save()
@@ -1254,7 +1217,6 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(2, self.Person.objects.count())
 
     def test_can_save_if_not_included(self):
-
         class EmbeddedDoc(EmbeddedDocument):
             pass
 
@@ -1341,10 +1303,7 @@ class InstanceTest(unittest.TestCase):
             doc2.update(set__name=doc1.name)
 
     def test_embedded_update(self):
-        """
+        """Test update on `EmbeddedDocumentField` fields."""
-        Test update on `EmbeddedDocumentField` fields
-        """
-
         class Page(EmbeddedDocument):
             log_message = StringField(verbose_name="Log message",
                                       required=True)
@@ -1365,11 +1324,9 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(site.page.log_message, "Error: Dummy message")
 
     def test_embedded_update_db_field(self):
+        """Test update on `EmbeddedDocumentField` fields when db_field
+        is other than default.
         """
-        Test update on `EmbeddedDocumentField` fields when db_field is other
-        than default.
-        """
-
         class Page(EmbeddedDocument):
             log_message = StringField(verbose_name="Log message",
                                       db_field="page_log_message",
@@ -1392,9 +1349,7 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(site.page.log_message, "Error: Dummy message")
 
     def test_save_only_changed_fields(self):
-        """Ensure save only sets / unsets changed fields
+        """Ensure save only sets / unsets changed fields."""
-        """
-
         class User(self.Person):
             active = BooleanField(default=True)
 
@@ -1514,8 +1469,8 @@ class InstanceTest(unittest.TestCase):
             self.assertEqual(q, 3)
 
     def test_set_unset_one_operation(self):
-        """Ensure that $set and $unset actions are performed in the same
+        """Ensure that $set and $unset actions are performed in the
-        operation.
+        same operation.
         """
         class FooBar(Document):
             foo = StringField(default=None)
@@ -1536,9 +1491,7 @@ class InstanceTest(unittest.TestCase):
             self.assertEqual(1, q)
 
     def test_save_only_changed_fields_recursive(self):
-        """Ensure save only sets / unsets changed fields
+        """Ensure save only sets / unsets changed fields."""
-        """
-
         class Comment(EmbeddedDocument):
             published = BooleanField(default=True)
 
@@ -1578,8 +1531,7 @@ class InstanceTest(unittest.TestCase):
         self.assertFalse(person.comments_dict['first_post'].published)
 
     def test_delete(self):
-        """Ensure that document may be deleted using the delete method.
+        """Ensure that document may be deleted using the delete method."""
-        """
         person = self.Person(name="Test User", age=30)
         person.save()
         self.assertEqual(self.Person.objects.count(), 1)
@@ -1587,33 +1539,34 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(self.Person.objects.count(), 0)
 
     def test_save_custom_id(self):
-        """Ensure that a document may be saved with a custom _id.
+        """Ensure that a document may be saved with a custom _id."""
-        """
+
         # Create person object and save it to the database
         person = self.Person(name='Test User', age=30,
                              id='497ce96f395f2f052a494fd4')
         person.save()
+
         # Ensure that the object is in the database with the correct _id
         collection = self.db[self.Person._get_collection_name()]
         person_obj = collection.find_one({'name': 'Test User'})
         self.assertEqual(str(person_obj['_id']), '497ce96f395f2f052a494fd4')
 
     def test_save_custom_pk(self):
-        """
+        """Ensure that a document may be saved with a custom _id using
-        Ensure that a document may be saved with a custom _id using pk alias.
+        pk alias.
         """
         # Create person object and save it to the database
         person = self.Person(name='Test User', age=30,
                              pk='497ce96f395f2f052a494fd4')
         person.save()
+
         # Ensure that the object is in the database with the correct _id
         collection = self.db[self.Person._get_collection_name()]
         person_obj = collection.find_one({'name': 'Test User'})
         self.assertEqual(str(person_obj['_id']), '497ce96f395f2f052a494fd4')
 
     def test_save_list(self):
-        """Ensure that a list field may be properly saved.
+        """Ensure that a list field may be properly saved."""
-        """
         class Comment(EmbeddedDocument):
             content = StringField()
 
@@ -1636,8 +1589,6 @@ class InstanceTest(unittest.TestCase):
         for comment_obj, comment in zip(post_obj['comments'], comments):
             self.assertEqual(comment_obj['content'], comment['content'])
 
-        BlogPost.drop_collection()
-
     def test_list_search_by_embedded(self):
         class User(Document):
             username = StringField(required=True)
@@ -1697,8 +1648,8 @@ class InstanceTest(unittest.TestCase):
             list(Page.objects.filter(comments__user=u3)))
 
     def test_save_embedded_document(self):
-        """Ensure that a document with an embedded document field may be
+        """Ensure that a document with an embedded document field may
-        saved in the database.
+        be saved in the database.
         """
         class EmployeeDetails(EmbeddedDocument):
             position = StringField()
@@ -1717,13 +1668,13 @@ class InstanceTest(unittest.TestCase):
         employee_obj = collection.find_one({'name': 'Test Employee'})
         self.assertEqual(employee_obj['name'], 'Test Employee')
         self.assertEqual(employee_obj['age'], 50)
+
         # Ensure that the 'details' embedded object saved correctly
         self.assertEqual(employee_obj['details']['position'], 'Developer')
 
     def test_embedded_update_after_save(self):
-        """
+        """Test update of `EmbeddedDocumentField` attached to a newly
-        Test update of `EmbeddedDocumentField` attached to a newly saved
+        saved document.
-        document.
         """
         class Page(EmbeddedDocument):
             log_message = StringField(verbose_name="Log message",
@@ -1744,8 +1695,8 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(site.page.log_message, "Error: Dummy message")
 
     def test_updating_an_embedded_document(self):
-        """Ensure that a document with an embedded document field may be
+        """Ensure that a document with an embedded document field may
-        saved in the database.
+        be saved in the database.
         """
         class EmployeeDetails(EmbeddedDocument):
             position = StringField()
@@ -1780,7 +1731,6 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(promoted_employee.details, None)
 
     def test_object_mixins(self):
-
         class NameMixin(object):
             name = StringField()
 
@@ -1819,9 +1769,9 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(t.count, 12)
 
     def test_save_reference(self):
-        """Ensure that a document reference field may be saved in the database.
+        """Ensure that a document reference field may be saved in the
+        database.
         """
-
         class BlogPost(Document):
             meta = {'collection': 'blogpost_1'}
             content = StringField()
@@ -1852,8 +1802,6 @@ class InstanceTest(unittest.TestCase):
         author = list(self.Person.objects(name='Test User'))[-1]
         self.assertEqual(author.age, 25)
 
-        BlogPost.drop_collection()
-
     def test_duplicate_db_fields_raise_invalid_document_error(self):
         """Ensure a InvalidDocumentError is thrown if duplicate fields
         declare the same db_field.
@@ -1864,7 +1812,7 @@ class InstanceTest(unittest.TestCase):
                 name2 = StringField(db_field='name')
 
     def test_invalid_son(self):
-        """Raise an error if loading invalid data"""
+        """Raise an error if loading invalid data."""
         class Occurrence(EmbeddedDocument):
             number = IntField()
 
@@ -1887,9 +1835,9 @@ class InstanceTest(unittest.TestCase):
             Word._from_son('this is not a valid SON dict')
 
     def test_reverse_delete_rule_cascade_and_nullify(self):
-        """Ensure that a referenced document is also deleted upon deletion.
+        """Ensure that a referenced document is also deleted upon
+        deletion.
         """
-
         class BlogPost(Document):
             content = StringField()
             author = ReferenceField(self.Person, reverse_delete_rule=CASCADE)
@@ -1944,7 +1892,8 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(Book.objects.count(), 0)
 
     def test_reverse_delete_rule_with_shared_id_among_collections(self):
-        """Ensure that cascade delete rule doesn't mix id among collections.
+        """Ensure that cascade delete rule doesn't mix id among
+        collections.
         """
         class User(Document):
             id = IntField(primary_key=True)
@@ -1975,10 +1924,9 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(Book.objects.get(), book_2)
 
     def test_reverse_delete_rule_with_document_inheritance(self):
-        """Ensure that a referenced document is also deleted upon deletion
+        """Ensure that a referenced document is also deleted upon
-        of a child document.
+        deletion of a child document.
         """
-
         class Writer(self.Person):
             pass
 
@@ -2010,10 +1958,9 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(BlogPost.objects.count(), 0)
 
     def test_reverse_delete_rule_cascade_and_nullify_complex_field(self):
-        """Ensure that a referenced document is also deleted upon deletion for
+        """Ensure that a referenced document is also deleted upon
-        complex fields.
+        deletion for complex fields.
         """
-
         class BlogPost(Document):
             content = StringField()
             authors = ListField(ReferenceField(
@@ -2022,7 +1969,6 @@ class InstanceTest(unittest.TestCase):
                 self.Person, reverse_delete_rule=NULLIFY))
 
         self.Person.drop_collection()
-
         BlogPost.drop_collection()
 
         author = self.Person(name='Test User')
@@ -2046,10 +1992,10 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(BlogPost.objects.count(), 0)
 
     def test_reverse_delete_rule_cascade_triggers_pre_delete_signal(self):
-        """ ensure the pre_delete signal is triggered upon a cascading deletion
+        """Ensure the pre_delete signal is triggered upon a cascading
-        setup a blog post with content, an author and editor
+        deletion setup a blog post with content, an author and editor
-        delete the author which triggers deletion of blogpost via cascade
+        delete the author which triggers deletion of blogpost via
-        blog post's pre_delete signal alters an editor attribute
+        cascade blog post's pre_delete signal alters an editor attribute.
         """
         class Editor(self.Person):
             review_queue = IntField(default=0)
@@ -2077,6 +2023,7 @@ class InstanceTest(unittest.TestCase):
 
         # delete the author, the post is also deleted due to the CASCADE rule
         author.delete()
+
         # the pre-delete signal should have decremented the editor's queue
         editor = Editor.objects(name='Max P.').get()
         self.assertEqual(editor.review_queue, 0)
@@ -2085,7 +2032,6 @@ class InstanceTest(unittest.TestCase):
         """Ensure that Bi-Directional relationships work with
         reverse_delete_rule
         """
-
         class Bar(Document):
             content = StringField()
             foo = ReferenceField('Foo')
@@ -2131,8 +2077,8 @@ class InstanceTest(unittest.TestCase):
                 mother = ReferenceField('Person', reverse_delete_rule=DENY)
 
     def test_reverse_delete_rule_cascade_recurs(self):
-        """Ensure that a chain of documents is also deleted upon cascaded
+        """Ensure that a chain of documents is also deleted upon
-        deletion.
+        cascaded deletion.
         """
         class BlogPost(Document):
             content = StringField()
@@ -2162,15 +2108,10 @@ class InstanceTest(unittest.TestCase):
         author.delete()
         self.assertEqual(Comment.objects.count(), 0)
 
-        self.Person.drop_collection()
-        BlogPost.drop_collection()
-        Comment.drop_collection()
-
     def test_reverse_delete_rule_deny(self):
-        """Ensure that a document cannot be referenced if there are still
+        """Ensure that a document cannot be referenced if there are
-        documents referring to it.
+        still documents referring to it.
         """
-
         class BlogPost(Document):
             content = StringField()
             author = ReferenceField(self.Person, reverse_delete_rule=DENY)
@@ -2198,11 +2139,7 @@ class InstanceTest(unittest.TestCase):
         author.delete()
         self.assertEqual(self.Person.objects.count(), 1)
 
-        self.Person.drop_collection()
-        BlogPost.drop_collection()
-
     def subclasses_and_unique_keys_works(self):
-
         class A(Document):
             pass
 
@@ -2218,12 +2155,9 @@ class InstanceTest(unittest.TestCase):
 
         self.assertEqual(A.objects.count(), 2)
         self.assertEqual(B.objects.count(), 1)
-        A.drop_collection()
-        B.drop_collection()
 
     def test_document_hash(self):
-        """Test document in list, dict, set
+        """Test document in list, dict, set."""
-        """
         class User(Document):
             pass
 
@@ -2266,11 +2200,9 @@ class InstanceTest(unittest.TestCase):
 
         # in Set
         all_user_set = set(User.objects.all())
-
         self.assertTrue(u1 in all_user_set)
 
     def test_picklable(self):
-
         pickle_doc = PickleTest(number=1, string="One", lists=['1', '2'])
         pickle_doc.embedded = PickleEmbedded()
         pickled_doc = pickle.dumps(pickle_doc)  # make sure pickling works even before the doc is saved
@@ -2296,7 +2228,6 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(pickle_doc.lists, ["1", "2", "3"])
 
     def test_regular_document_pickle(self):
-
         pickle_doc = PickleTest(number=1, string="One", lists=['1', '2'])
         pickled_doc = pickle.dumps(pickle_doc)  # make sure pickling works even before the doc is saved
         pickle_doc.save()
@@ -2319,7 +2250,6 @@ class InstanceTest(unittest.TestCase):
         fixtures.PickleTest = PickleTest
 
     def test_dynamic_document_pickle(self):
-
         pickle_doc = PickleDynamicTest(
             name="test", number=1, string="One", lists=['1', '2'])
         pickle_doc.embedded = PickleDynamicEmbedded(foo="Bar")
@@ -2358,7 +2288,6 @@ class InstanceTest(unittest.TestCase):
                 validate = DictField()
 
     def test_mutating_documents(self):
-
         class B(EmbeddedDocument):
             field1 = StringField(default='field1')
 
@@ -2366,6 +2295,7 @@ class InstanceTest(unittest.TestCase):
             b = EmbeddedDocumentField(B, default=lambda: B())
 
         A.drop_collection()
+
         a = A()
         a.save()
         a.reload()
@@ -2389,12 +2319,13 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(a.b.field2.c_field, 'new value')
 
     def test_can_save_false_values(self):
-        """Ensures you can save False values on save"""
+        """Ensures you can save False values on save."""
         class Doc(Document):
             foo = StringField()
             archived = BooleanField(default=False, required=True)
 
         Doc.drop_collection()
+
         d = Doc()
         d.save()
         d.archived = False
@@ -2403,11 +2334,12 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(Doc.objects(archived=False).count(), 1)
 
     def test_can_save_false_values_dynamic(self):
-        """Ensures you can save False values on dynamic docs"""
+        """Ensures you can save False values on dynamic docs."""
         class Doc(DynamicDocument):
             foo = StringField()
 
         Doc.drop_collection()
+
         d = Doc()
         d.save()
         d.archived = False
@@ -2447,7 +2379,7 @@ class InstanceTest(unittest.TestCase):
             Collection.update = orig_update
 
     def test_db_alias_tests(self):
-        """ DB Alias tests """
+        """DB Alias tests."""
         # mongoenginetest - Is default connection alias from setUp()
         # Register Aliases
         register_connection('testdb-1', 'mongoenginetest2')
@@ -2509,8 +2441,7 @@ class InstanceTest(unittest.TestCase):
             get_db("testdb-3")[AuthorBooks._get_collection_name()])
 
     def test_db_alias_overrides(self):
-        """db_alias can be overriden
+        """Test db_alias can be overriden."""
-        """
         # Register a connection with db_alias testdb-2
         register_connection('testdb-2', 'mongoenginetest2')
 
@@ -2534,8 +2465,7 @@ class InstanceTest(unittest.TestCase):
                          B._get_collection().database.name)
 
     def test_db_alias_propagates(self):
-        """db_alias propagates?
+        """db_alias propagates?"""
-        """
         register_connection('testdb-1', 'mongoenginetest2')
 
         class A(Document):
@@ -2548,8 +2478,7 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual('testdb-1', B._meta.get('db_alias'))
 
     def test_db_ref_usage(self):
-        """ DB Ref usage  in dict_fields"""
+        """DB Ref usage in dict_fields."""
-
         class User(Document):
             name = StringField()
 
@@ -2784,7 +2713,6 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(user.thing._data['data'], [1, 2, 3])
 
     def test_spaces_in_keys(self):
-
         class Embedded(DynamicEmbeddedDocument):
             pass
 
@@ -2873,7 +2801,6 @@ class InstanceTest(unittest.TestCase):
             log.machine = "127.0.0.1"
 
     def test_kwargs_simple(self):
-
         class Embedded(EmbeddedDocument):
             name = StringField()
 
@@ -2893,7 +2820,6 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(classic_doc._data, dict_doc._data)
 
     def test_kwargs_complex(self):
-
         class Embedded(EmbeddedDocument):
             name = StringField()
 
@@ -2916,36 +2842,35 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(classic_doc._data, dict_doc._data)
 
     def test_positional_creation(self):
-        """Ensure that document may be created using positional arguments.
+        """Ensure that document may be created using positional arguments."""
-        """
         person = self.Person("Test User", 42)
         self.assertEqual(person.name, "Test User")
         self.assertEqual(person.age, 42)
 
     def test_mixed_creation(self):
-        """Ensure that document may be created using mixed arguments.
+        """Ensure that document may be created using mixed arguments."""
-        """
         person = self.Person("Test User", age=42)
         self.assertEqual(person.name, "Test User")
         self.assertEqual(person.age, 42)
 
     def test_positional_creation_embedded(self):
-        """Ensure that embedded document may be created using positional arguments.
+        """Ensure that embedded document may be created using positional
+        arguments.
         """
         job = self.Job("Test Job", 4)
         self.assertEqual(job.name, "Test Job")
         self.assertEqual(job.years, 4)
 
     def test_mixed_creation_embedded(self):
-        """Ensure that embedded document may be created using mixed arguments.
+        """Ensure that embedded document may be created using mixed
+        arguments.
         """
         job = self.Job("Test Job", years=4)
         self.assertEqual(job.name, "Test Job")
         self.assertEqual(job.years, 4)
 
     def test_mixed_creation_dynamic(self):
-        """Ensure that document may be created using mixed arguments.
+        """Ensure that document may be created using mixed arguments."""
-        """
         class Person(DynamicDocument):
             name = StringField()
 
@@ -2954,14 +2879,14 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(person.age, 42)
 
     def test_bad_mixed_creation(self):
-        """Ensure that document gives correct error when duplicating arguments
+        """Ensure that document gives correct error when duplicating
+        arguments.
         """
         with self.assertRaises(TypeError):
             return self.Person("Test User", 42, name="Bad User")
 
     def test_data_contains_id_field(self):
-        """Ensure that asking for _data returns 'id'
+        """Ensure that asking for _data returns 'id'."""
-        """
         class Person(Document):
             name = StringField()
 
@@ -2973,7 +2898,6 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(person._data.get('id'), person.id)
 
     def test_complex_nesting_document_and_embedded_document(self):
-
         class Macro(EmbeddedDocument):
             value = DynamicField(default="UNDEFINED")
 
@@ -3016,7 +2940,6 @@ class InstanceTest(unittest.TestCase):
             system.nodes["node"].parameters["param"].macros["test"].value)
 
     def test_embedded_document_equality(self):
-
         class Test(Document):
             field = StringField(required=True)
 
@@ -3202,8 +3125,7 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(idx, 2)
 
     def test_falsey_pk(self):
-        """Ensure that we can create and update a document with Falsey PK.
+        """Ensure that we can create and update a document with Falsey PK."""
-        """
         class Person(Document):
             age = IntField(primary_key=True)
             height = FloatField()

tests/test_connection.py

@@ -198,19 +198,6 @@ class ConnectionTest(unittest.TestCase):
         self.assertTrue(isinstance(db, pymongo.database.Database))
         self.assertEqual(db.name, 'test')
 
-    def test_connect_uri_with_replicaset(self):
-        """Ensure connect() works when specifying a replicaSet."""
-        if IS_PYMONGO_3:
-            c = connect(host='mongodb://localhost/test?replicaSet=local-rs')
-            db = get_db()
-            self.assertTrue(isinstance(db, pymongo.database.Database))
-            self.assertEqual(db.name, 'test')
-        else:
-            # PyMongo < v3.x raises an exception:
-            # "localhost:27017 is not a member of replica set local-rs"
-            with self.assertRaises(MongoEngineConnectionError):
-                c = connect(host='mongodb://localhost/test?replicaSet=local-rs')
-
     def test_uri_without_credentials_doesnt_override_conn_settings(self):
         """Ensure connect() uses the username & password params if the URI
         doesn't explicitly specify them.
@@ -332,6 +319,38 @@ class ConnectionTest(unittest.TestCase):
             self.assertEqual(dict(conn1.write_concern), {'w': 1, 'j': True})
             self.assertEqual(dict(conn2.write_concern), {'w': 1, 'j': True})
 
+    def test_connect_with_replicaset_via_uri(self):
+        """Ensure connect() works when specifying a replicaSet via the
+        MongoDB URI.
+        """
+        if IS_PYMONGO_3:
+            c = connect(host='mongodb://localhost/test?replicaSet=local-rs')
+            db = get_db()
+            self.assertTrue(isinstance(db, pymongo.database.Database))
+            self.assertEqual(db.name, 'test')
+        else:
+            # PyMongo < v3.x raises an exception:
+            # "localhost:27017 is not a member of replica set local-rs"
+            with self.assertRaises(MongoEngineConnectionError):
+                c = connect(host='mongodb://localhost/test?replicaSet=local-rs')
+
+    def test_connect_with_replicaset_via_kwargs(self):
+        """Ensure connect() works when specifying a replicaSet via the
+        connection kwargs
+        """
+        if IS_PYMONGO_3:
+            c = connect(replicaset='local-rs')
+            self.assertEqual(c._MongoClient__options.replica_set_name,
+                             'local-rs')
+            db = get_db()
+            self.assertTrue(isinstance(db, pymongo.database.Database))
+            self.assertEqual(db.name, 'test')
+        else:
+            # PyMongo < v3.x raises an exception:
+            # "localhost:27017 is not a member of replica set local-rs"
+            with self.assertRaises(MongoEngineConnectionError):
+                c = connect(replicaset='local-rs')
+
     def test_datetime(self):
         connect('mongoenginetest', tz_aware=True)
         d = datetime.datetime(2010, 5, 5, tzinfo=utc)