diff --git a/tests/document/inheritance.py b/tests/document/inheritance.py
index ab73824f..2897e1d1 100644
--- a/tests/document/inheritance.py
+++ b/tests/document/inheritance.py
@@ -251,19 +251,17 @@ class InheritanceTest(unittest.TestCase):
         self.assertEqual(classes, [Human])
 
     def test_allow_inheritance(self):
-        """Ensure that inheritance may be disabled on simple classes and that
-        _cls and _subclasses will not be used.
+        """Ensure that inheritance is disabled by default on simple
+        classes and that _cls will not be used.
         """
-
         class Animal(Document):
             name = StringField()
 
-        def create_dog_class():
+        # can't inherit because Animal didn't explicitly allow inheritance
+        with self.assertRaises(ValueError):
             class Dog(Animal):
                 pass
 
-        self.assertRaises(ValueError, create_dog_class)
-
         # Check that _cls etc aren't present on simple documents
         dog = Animal(name='dog').save()
         self.assertEqual(dog.to_mongo().keys(), ['_id', 'name'])
@@ -273,17 +271,15 @@ class InheritanceTest(unittest.TestCase):
         self.assertFalse('_cls' in obj)
 
     def test_cant_turn_off_inheritance_on_subclass(self):
-        """Ensure if inheritance is on in a subclass you cant turn it off
+        """Ensure if inheritance is on in a subclass you cant turn it off.
         """
-
         class Animal(Document):
             name = StringField()
             meta = {'allow_inheritance': True}
 
-        def create_mammal_class():
+        with self.assertRaises(ValueError):
             class Mammal(Animal):
                 meta = {'allow_inheritance': False}
-        self.assertRaises(ValueError, create_mammal_class)
 
     def test_allow_inheritance_abstract_document(self):
         """Ensure that abstract documents can set inheritance rules and that
@@ -296,10 +292,9 @@ class InheritanceTest(unittest.TestCase):
         class Animal(FinalDocument):
             name = StringField()
 
-        def create_mammal_class():
+        with self.assertRaises(ValueError):
             class Mammal(Animal):
                 pass
-        self.assertRaises(ValueError, create_mammal_class)
 
         # Check that _cls isn't present in simple documents
         doc = Animal(name='dog')
@@ -358,29 +353,26 @@ class InheritanceTest(unittest.TestCase):
         self.assertEqual(berlin.pk, berlin.auto_id_0)
 
     def test_abstract_document_creation_does_not_fail(self):
-
         class City(Document):
             continent = StringField()
             meta = {'abstract': True,
                     'allow_inheritance': False}
+
         bkk = City(continent='asia')
         self.assertEqual(None, bkk.pk)
         # TODO: expected error? Shouldn't we create a new error type?
-        self.assertRaises(KeyError, lambda: setattr(bkk, 'pk', 1))
+        with self.assertRaises(KeyError):
+            setattr(bkk, 'pk', 1)
 
     def test_allow_inheritance_embedded_document(self):
-        """Ensure embedded documents respect inheritance
-        """
-
+        """Ensure embedded documents respect inheritance."""
         class Comment(EmbeddedDocument):
             content = StringField()
 
-        def create_special_comment():
+        with self.assertRaises(ValueError):
             class SpecialComment(Comment):
                 pass
 
-        self.assertRaises(ValueError, create_special_comment)
-
         doc = Comment(content='test')
         self.assertFalse('_cls' in doc.to_mongo())
 
@@ -452,11 +444,11 @@ class InheritanceTest(unittest.TestCase):
         self.assertEqual(Guppy._get_collection_name(), 'fish')
         self.assertEqual(Human._get_collection_name(), 'human')
 
-        def create_bad_abstract():
+        # ensure that a subclass of a non-abstract class can't be abstract
+        with self.assertRaises(ValueError):
             class EvilHuman(Human):
                 evil = BooleanField(default=True)
                 meta = {'abstract': True}
-        self.assertRaises(ValueError, create_bad_abstract)
 
     def test_abstract_embedded_documents(self):
         # 789: EmbeddedDocument shouldn't inherit abstract
diff --git a/tests/document/instance.py b/tests/document/instance.py
index 43cd2d68..b92bafa9 100644
--- a/tests/document/instance.py
+++ b/tests/document/instance.py
@@ -99,21 +99,18 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(options['size'], 4096)
 
         # Check that the document cannot be redefined with different options
-        def recreate_log_document():
-            class Log(Document):
-                date = DateTimeField(default=datetime.now)
-                meta = {
-                    'max_documents': 11,
-                }
-            # Create the collection by accessing Document.objects
-            Log.objects
-        self.assertRaises(InvalidCollectionError, recreate_log_document)
+        class Log(Document):
+            date = DateTimeField(default=datetime.now)
+            meta = {
+                'max_documents': 11,
+            }
 
-        Log.drop_collection()
+        # Accessing Document.objects creates the collection
+        with self.assertRaises(InvalidCollectionError):
+            Log.objects
 
     def test_capped_collection_default(self):
-        """Ensure that capped collections defaults work properly.
-        """
+        """Ensure that capped collections defaults work properly."""
         class Log(Document):
             date = DateTimeField(default=datetime.now)
             meta = {
@@ -131,16 +128,14 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(options['size'], 10 * 2**20)
 
         # Check that the document with default value can be recreated
-        def recreate_log_document():
-            class Log(Document):
-                date = DateTimeField(default=datetime.now)
-                meta = {
-                    'max_documents': 10,
-                }
-            # Create the collection by accessing Document.objects
-            Log.objects
-        recreate_log_document()
-        Log.drop_collection()
+        class Log(Document):
+            date = DateTimeField(default=datetime.now)
+            meta = {
+                'max_documents': 10,
+            }
+
+        # Create the collection by accessing Document.objects
+        Log.objects
 
     def test_capped_collection_no_max_size_problems(self):
         """Ensure that capped collections with odd max_size work properly.
@@ -163,16 +158,14 @@ class InstanceTest(unittest.TestCase):
         self.assertTrue(options['size'] >= 10000)
 
         # Check that the document with odd max_size value can be recreated
-        def recreate_log_document():
-            class Log(Document):
-                date = DateTimeField(default=datetime.now)
-                meta = {
-                    'max_size': 10000,
-                }
-            # Create the collection by accessing Document.objects
-            Log.objects
-        recreate_log_document()
-        Log.drop_collection()
+        class Log(Document):
+            date = DateTimeField(default=datetime.now)
+            meta = {
+                'max_size': 10000,
+            }
+
+        # Create the collection by accessing Document.objects
+        Log.objects
 
     def test_repr(self):
         """Ensure that unicode representation works
@@ -353,14 +346,14 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(User._fields['username'].db_field, '_id')
         self.assertEqual(User._meta['id_field'], 'username')
 
-        def create_invalid_user():
-            User(name='test').save()  # no primary key field
-        self.assertRaises(ValidationError, create_invalid_user)
+        # test no primary key field
+        self.assertRaises(ValidationError, User(name='test').save)
 
-        def define_invalid_user():
+        # define a subclass with a different primary key field than the
+        # parent
+        with self.assertRaises(ValueError):
             class EmailUser(User):
                 email = StringField(primary_key=True)
-        self.assertRaises(ValueError, define_invalid_user)
 
         class EmailUser(User):
             email = StringField()
@@ -410,9 +403,8 @@ class InstanceTest(unittest.TestCase):
         # and the NicePlace model not being imported in at query time.
         del(_document_registry['Place.NicePlace'])
 
-        def query_without_importing_nice_place():
+        with self.assertRaises(NotRegistered):
             list(Place.objects.all())
-        self.assertRaises(NotRegistered, query_without_importing_nice_place)
 
     def test_document_registry_regressions(self):
 
@@ -794,8 +786,10 @@ class InstanceTest(unittest.TestCase):
 
     def test_modify_empty(self):
         doc = self.Person(name="bob", age=10).save()
-        self.assertRaises(
-            InvalidDocumentError, lambda: self.Person().modify(set__age=10))
+
+        with self.assertRaises(InvalidDocumentError):
+            self.Person().modify(set__age=10)
+
         self.assertDbEqual([dict(doc.to_mongo())])
 
     def test_modify_invalid_query(self):
@@ -803,9 +797,8 @@ class InstanceTest(unittest.TestCase):
         doc2 = self.Person(name="jim", age=20).save()
         docs = [dict(doc1.to_mongo()), dict(doc2.to_mongo())]
 
-        self.assertRaises(
-            InvalidQueryError,
-            lambda: doc1.modify({'id': doc2.id}, set__value=20))
+        with self.assertRaises(InvalidQueryError):
+            doc1.modify({'id': doc2.id}, set__value=20)
 
         self.assertDbEqual(docs)
 
@@ -1289,12 +1282,11 @@ class InstanceTest(unittest.TestCase):
 
     def test_document_update(self):
 
-        def update_not_saved_raises():
+        # try updating a non-saved document
+        with self.assertRaises(OperationError):
             person = self.Person(name='dcrosta')
             person.update(set__name='Dan Crosta')
 
-        self.assertRaises(OperationError, update_not_saved_raises)
-
         author = self.Person(name='dcrosta')
         author.save()
 
@@ -1304,19 +1296,17 @@ class InstanceTest(unittest.TestCase):
         p1 = self.Person.objects.first()
         self.assertEqual(p1.name, author.name)
 
-        def update_no_value_raises():
+        # try sending an empty update
+        with self.assertRaises(OperationError):
             person = self.Person.objects.first()
             person.update()
 
-        self.assertRaises(OperationError, update_no_value_raises)
-
-        def update_no_op_should_default_to_set():
-            person = self.Person.objects.first()
-            person.update(name="Dan")
-            person.reload()
-            return person.name
-
-        self.assertEqual("Dan", update_no_op_should_default_to_set())
+        # update that doesn't explicitly specify an operator should default
+        # to 'set__'
+        person = self.Person.objects.first()
+        person.update(name="Dan")
+        person.reload()
+        self.assertEqual("Dan", person.name)
 
     def test_update_unique_field(self):
         class Doc(Document):
@@ -1325,8 +1315,8 @@ class InstanceTest(unittest.TestCase):
         doc1 = Doc(name="first").save()
         doc2 = Doc(name="second").save()
 
-        self.assertRaises(NotUniqueError, lambda:
-                          doc2.update(set__name=doc1.name))
+        with self.assertRaises(NotUniqueError):
+            doc2.update(set__name=doc1.name)
 
     def test_embedded_update(self):
         """
@@ -1844,15 +1834,13 @@ class InstanceTest(unittest.TestCase):
 
     def test_duplicate_db_fields_raise_invalid_document_error(self):
         """Ensure a InvalidDocumentError is thrown if duplicate fields
-        declare the same db_field"""
-
-        def throw_invalid_document_error():
+        declare the same db_field.
+        """
+        with self.assertRaises(InvalidDocumentError):
             class Foo(Document):
                 name = StringField()
                 name2 = StringField(db_field='name')
 
-        self.assertRaises(InvalidDocumentError, throw_invalid_document_error)
-
     def test_invalid_son(self):
         """Raise an error if loading invalid data"""
         class Occurrence(EmbeddedDocument):
@@ -1864,11 +1852,13 @@ class InstanceTest(unittest.TestCase):
             forms = ListField(StringField(), default=list)
             occurs = ListField(EmbeddedDocumentField(Occurrence), default=list)
 
-        def raise_invalid_document():
-            Word._from_son({'stem': [1, 2, 3], 'forms': 1, 'count': 'one',
-                            'occurs': {"hello": None}})
-
-        self.assertRaises(InvalidDocumentError, raise_invalid_document)
+        with self.assertRaises(InvalidDocumentError):
+            Word._from_son({
+                'stem': [1, 2, 3],
+                'forms': 1,
+                'count': 'one',
+                'occurs': {"hello": None}
+            })
 
     def test_reverse_delete_rule_cascade_and_nullify(self):
         """Ensure that a referenced document is also deleted upon deletion.
@@ -2099,8 +2089,7 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(Bar.objects.get().foo, None)
 
     def test_invalid_reverse_delete_rule_raise_errors(self):
-
-        def throw_invalid_document_error():
+        with self.assertRaises(InvalidDocumentError):
             class Blog(Document):
                 content = StringField()
                 authors = MapField(ReferenceField(
@@ -2110,21 +2099,15 @@ class InstanceTest(unittest.TestCase):
                         self.Person,
                         reverse_delete_rule=NULLIFY))
 
-        self.assertRaises(InvalidDocumentError, throw_invalid_document_error)
-
-        def throw_invalid_document_error_embedded():
+        with self.assertRaises(InvalidDocumentError):
             class Parents(EmbeddedDocument):
                 father = ReferenceField('Person', reverse_delete_rule=DENY)
                 mother = ReferenceField('Person', reverse_delete_rule=DENY)
 
-        self.assertRaises(
-            InvalidDocumentError, throw_invalid_document_error_embedded)
-
     def test_reverse_delete_rule_cascade_recurs(self):
         """Ensure that a chain of documents is also deleted upon cascaded
         deletion.
         """
-
         class BlogPost(Document):
             content = StringField()
             author = ReferenceField(self.Person, reverse_delete_rule=CASCADE)
@@ -2340,15 +2323,14 @@ class InstanceTest(unittest.TestCase):
         pickle_doc.save()
         pickle_doc.delete()
 
-    def test_throw_invalid_document_error(self):
-
-        # test handles people trying to upsert
-        def throw_invalid_document_error():
+    def test_override_method_with_field(self):
+        """Test creating a field with a field name that would override
+        the "validate" method.
+        """
+        with self.assertRaises(InvalidDocumentError):
             class Blog(Document):
                 validate = DictField()
 
-        self.assertRaises(InvalidDocumentError, throw_invalid_document_error)
-
     def test_mutating_documents(self):
 
         class B(EmbeddedDocument):
@@ -2811,11 +2793,10 @@ class InstanceTest(unittest.TestCase):
         log.log = "Saving"
         log.save()
 
-        def change_shard_key():
+        # try to change the shard key
+        with self.assertRaises(OperationError):
             log.machine = "127.0.0.1"
 
-        self.assertRaises(OperationError, change_shard_key)
-
     def test_shard_key_in_embedded_document(self):
         class Foo(EmbeddedDocument):
             foo = StringField()
@@ -2836,12 +2817,11 @@ class InstanceTest(unittest.TestCase):
         bar_doc.bar = 'baz'
         bar_doc.save()
 
-        def change_shard_key():
+        # try to change the shard key
+        with self.assertRaises(OperationError):
             bar_doc.foo.foo = 'something'
             bar_doc.save()
 
-        self.assertRaises(OperationError, change_shard_key)
-
     def test_shard_key_primary(self):
         class LogEntry(Document):
             machine = StringField(primary_key=True)
@@ -2862,11 +2842,10 @@ class InstanceTest(unittest.TestCase):
         log.log = "Saving"
         log.save()
 
-        def change_shard_key():
+        # try to change the shard key
+        with self.assertRaises(OperationError):
             log.machine = "127.0.0.1"
 
-        self.assertRaises(OperationError, change_shard_key)
-
     def test_kwargs_simple(self):
 
         class Embedded(EmbeddedDocument):
@@ -2951,11 +2930,9 @@ class InstanceTest(unittest.TestCase):
     def test_bad_mixed_creation(self):
         """Ensure that document gives correct error when duplicating arguments
         """
-        def construct_bad_instance():
+        with self.assertRaises(TypeError):
             return self.Person("Test User", 42, name="Bad User")
 
-        self.assertRaises(TypeError, construct_bad_instance)
-
     def test_data_contains_id_field(self):
         """Ensure that asking for _data returns 'id'
         """
diff --git a/tests/document/validation.py b/tests/document/validation.py
index 1ff88ab5..105bc8b0 100644
--- a/tests/document/validation.py
+++ b/tests/document/validation.py
@@ -153,14 +153,14 @@ class ValidatorErrorTest(unittest.TestCase):
 
         s = SubDoc()
 
-        self.assertRaises(ValidationError, lambda: s.validate())
+        self.assertRaises(ValidationError, s.validate)
 
         d1.e = s
         d2.e = s
 
         del d1
 
-        self.assertRaises(ValidationError, lambda: d2.validate())
+        self.assertRaises(ValidationError, d2.validate)
 
     def test_parent_reference_in_child_document(self):
         """
diff --git a/tests/fields/fields.py b/tests/fields/fields.py
index b4396f39..17b76742 100644
--- a/tests/fields/fields.py
+++ b/tests/fields/fields.py
@@ -1115,12 +1115,11 @@ class FieldTest(unittest.TestCase):
         e.mapping = [1]
         e.save()
 
-        def create_invalid_mapping():
+        # try creating an invalid mapping
+        with self.assertRaises(ValidationError):
             e.mapping = ["abc"]
             e.save()
 
-        self.assertRaises(ValidationError, create_invalid_mapping)
-
         Simple.drop_collection()
 
     def test_list_field_rejects_strings(self):
@@ -1387,12 +1386,11 @@ class FieldTest(unittest.TestCase):
         e.mapping['someint'] = 1
         e.save()
 
-        def create_invalid_mapping():
+        # try creating an invalid mapping
+        with self.assertRaises(ValidationError):
             e.mapping['somestring'] = "abc"
             e.save()
 
-        self.assertRaises(ValidationError, create_invalid_mapping)
-
         Simple.drop_collection()
 
     def test_dictfield_complex(self):
@@ -1465,11 +1463,10 @@ class FieldTest(unittest.TestCase):
         self.assertEqual(BaseDict, type(e.mapping))
         self.assertEqual({"ints": [3, 4]}, e.mapping)
 
-        def create_invalid_mapping():
+        # try creating an invalid mapping
+        with self.assertRaises(ValueError):
             e.update(set__mapping={"somestrings": ["foo", "bar", ]})
 
-        self.assertRaises(ValueError, create_invalid_mapping)
-
         Simple.drop_collection()
 
     def test_mapfield(self):
@@ -1484,18 +1481,14 @@ class FieldTest(unittest.TestCase):
         e.mapping['someint'] = 1
         e.save()
 
-        def create_invalid_mapping():
+        with self.assertRaises(ValidationError):
             e.mapping['somestring'] = "abc"
             e.save()
 
-        self.assertRaises(ValidationError, create_invalid_mapping)
-
-        def create_invalid_class():
+        with self.assertRaises(ValidationError):
             class NoDeclaredType(Document):
                 mapping = MapField()
 
-        self.assertRaises(ValidationError, create_invalid_class)
-
         Simple.drop_collection()
 
     def test_complex_mapfield(self):
@@ -1524,14 +1517,10 @@ class FieldTest(unittest.TestCase):
         self.assertTrue(isinstance(e2.mapping['somestring'], StringSetting))
         self.assertTrue(isinstance(e2.mapping['someint'], IntegerSetting))
 
-        def create_invalid_mapping():
+        with self.assertRaises(ValidationError):
             e.mapping['someint'] = 123
             e.save()
 
-        self.assertRaises(ValidationError, create_invalid_mapping)
-
-        Extensible.drop_collection()
-
     def test_embedded_mapfield_db_field(self):
 
         class Embedded(EmbeddedDocument):
@@ -1741,8 +1730,8 @@ class FieldTest(unittest.TestCase):
         # Reference is no longer valid
         foo.delete()
         bar = Bar.objects.get()
-        self.assertRaises(DoesNotExist, lambda: getattr(bar, 'ref'))
-        self.assertRaises(DoesNotExist, lambda: getattr(bar, 'generic_ref'))
+        self.assertRaises(DoesNotExist, getattr, bar, 'ref')
+        self.assertRaises(DoesNotExist, getattr, bar, 'generic_ref')
 
         # When auto_dereference is disabled, there is no trouble returning DBRef
         bar = Bar.objects.get()
@@ -2017,7 +2006,7 @@ class FieldTest(unittest.TestCase):
         })
 
     def test_cached_reference_fields_on_embedded_documents(self):
-        def build():
+        with self.assertRaises(InvalidDocumentError):
             class Test(Document):
                 name = StringField()
 
@@ -2026,8 +2015,6 @@ class FieldTest(unittest.TestCase):
                     'test': CachedReferenceField(Test)
             })
 
-        self.assertRaises(InvalidDocumentError, build)
-
     def test_cached_reference_auto_sync(self):
         class Person(Document):
             TYPES = (
@@ -3815,9 +3802,7 @@ class EmbeddedDocumentListFieldTestCase(unittest.TestCase):
         filtered = self.post1.comments.filter()
 
         # Ensure nothing was changed
-        # < 2.6 Incompatible >
-        # self.assertListEqual(filtered, self.post1.comments)
-        self.assertEqual(filtered, self.post1.comments)
+        self.assertListEqual(filtered, self.post1.comments)
 
     def test_single_keyword_filter(self):
         """
@@ -3868,10 +3853,8 @@ class EmbeddedDocumentListFieldTestCase(unittest.TestCase):
         Tests the filter method of a List of Embedded Documents
         when the keyword is not a known keyword.
         """
-        # < 2.6 Incompatible >
-        # with self.assertRaises(AttributeError):
-        #    self.post2.comments.filter(year=2)
-        self.assertRaises(AttributeError, self.post2.comments.filter, year=2)
+        with self.assertRaises(AttributeError):
+            self.post2.comments.filter(year=2)
 
     def test_no_keyword_exclude(self):
         """
@@ -3881,9 +3864,7 @@ class EmbeddedDocumentListFieldTestCase(unittest.TestCase):
         filtered = self.post1.comments.exclude()
 
         # Ensure everything was removed
-        # < 2.6 Incompatible >
-        # self.assertListEqual(filtered, [])
-        self.assertEqual(filtered, [])
+        self.assertListEqual(filtered, [])
 
     def test_single_keyword_exclude(self):
         """
@@ -3929,10 +3910,8 @@ class EmbeddedDocumentListFieldTestCase(unittest.TestCase):
         Tests the exclude method of a List of Embedded Documents
         when the keyword is not a known keyword.
         """
-        # < 2.6 Incompatible >
-        # with self.assertRaises(AttributeError):
-        #    self.post2.comments.exclude(year=2)
-        self.assertRaises(AttributeError, self.post2.comments.exclude, year=2)
+        with self.assertRaises(AttributeError):
+            self.post2.comments.exclude(year=2)
 
     def test_chained_filter_exclude(self):
         """
@@ -3970,10 +3949,7 @@ class EmbeddedDocumentListFieldTestCase(unittest.TestCase):
         single keyword.
         """
         comment = self.post1.comments.get(author='user1')
-
-        # < 2.6 Incompatible >
-        # self.assertIsInstance(comment, self.Comments)
-        self.assertTrue(isinstance(comment, self.Comments))
+        self.assertIsInstance(comment, self.Comments)
         self.assertEqual(comment.author, 'user1')
 
     def test_multi_keyword_get(self):
@@ -3982,10 +3958,7 @@ class EmbeddedDocumentListFieldTestCase(unittest.TestCase):
         multiple keywords.
         """
         comment = self.post2.comments.get(author='user2', message='message2')
-
-        # < 2.6 Incompatible >
-        # self.assertIsInstance(comment, self.Comments)
-        self.assertTrue(isinstance(comment, self.Comments))
+        self.assertIsInstance(comment, self.Comments)
         self.assertEqual(comment.author, 'user2')
         self.assertEqual(comment.message, 'message2')
 
@@ -3994,44 +3967,32 @@ class EmbeddedDocumentListFieldTestCase(unittest.TestCase):
         Tests the get method of a List of Embedded Documents without
         a keyword to return multiple documents.
         """
-        # < 2.6 Incompatible >
-        # with self.assertRaises(MultipleObjectsReturned):
-        #    self.post1.comments.get()
-        self.assertRaises(MultipleObjectsReturned, self.post1.comments.get)
+        with self.assertRaises(MultipleObjectsReturned):
+            self.post1.comments.get()
 
     def test_keyword_multiple_return_get(self):
         """
         Tests the get method of a List of Embedded Documents with a keyword
         to return multiple documents.
         """
-        # < 2.6 Incompatible >
-        # with self.assertRaises(MultipleObjectsReturned):
-        #    self.post2.comments.get(author='user2')
-        self.assertRaises(
-            MultipleObjectsReturned, self.post2.comments.get, author='user2'
-        )
+        with self.assertRaises(MultipleObjectsReturned):
+            self.post2.comments.get(author='user2')
 
     def test_unknown_keyword_get(self):
         """
         Tests the get method of a List of Embedded Documents with an
         unknown keyword.
         """
-        # < 2.6 Incompatible >
-        # with self.assertRaises(AttributeError):
-        #    self.post2.comments.get(year=2020)
-        self.assertRaises(AttributeError, self.post2.comments.get, year=2020)
+        with self.assertRaises(AttributeError):
+            self.post2.comments.get(year=2020)
 
     def test_no_result_get(self):
         """
         Tests the get method of a List of Embedded Documents where get
         returns no results.
         """
-        # < 2.6 Incompatible >
-        # with self.assertRaises(DoesNotExist):
-        #    self.post1.comments.get(author='user3')
-        self.assertRaises(
-            DoesNotExist, self.post1.comments.get, author='user3'
-        )
+        with self.assertRaises(DoesNotExist):
+            self.post1.comments.get(author='user3')
 
     def test_first(self):
         """
@@ -4041,9 +4002,7 @@ class EmbeddedDocumentListFieldTestCase(unittest.TestCase):
         comment = self.post1.comments.first()
 
         # Ensure a Comment object was returned.
-        # < 2.6 Incompatible >
-        # self.assertIsInstance(comment, self.Comments)
-        self.assertTrue(isinstance(comment, self.Comments))
+        self.assertIsInstance(comment, self.Comments)
         self.assertEqual(comment, self.post1.comments[0])
 
     def test_create(self):
@@ -4056,22 +4015,14 @@ class EmbeddedDocumentListFieldTestCase(unittest.TestCase):
         self.post1.save()
 
         # Ensure the returned value is the comment object.
-        # < 2.6 Incompatible >
-        # self.assertIsInstance(comment, self.Comments)
-        self.assertTrue(isinstance(comment, self.Comments))
+        self.assertIsInstance(comment, self.Comments)
         self.assertEqual(comment.author, 'user4')
         self.assertEqual(comment.message, 'message1')
 
         # Ensure the new comment was actually saved to the database.
-        # < 2.6 Incompatible >
-        # self.assertIn(
-        #    comment,
-        #    self.BlogPost.objects(comments__author='user4')[0].comments
-        # )
-        self.assertTrue(
-            comment in self.BlogPost.objects(
-                comments__author='user4'
-            )[0].comments
+        self.assertIn(
+            comment,
+            self.BlogPost.objects(comments__author='user4')[0].comments
         )
 
     def test_filtered_create(self):
@@ -4086,22 +4037,14 @@ class EmbeddedDocumentListFieldTestCase(unittest.TestCase):
         self.post1.save()
 
         # Ensure the returned value is the comment object.
-        # < 2.6 Incompatible >
-        # self.assertIsInstance(comment, self.Comments)
-        self.assertTrue(isinstance(comment, self.Comments))
+        self.assertIsInstance(comment, self.Comments)
         self.assertEqual(comment.author, 'user4')
         self.assertEqual(comment.message, 'message1')
 
         # Ensure the new comment was actually saved to the database.
-        # < 2.6 Incompatible >
-        # self.assertIn(
-        #    comment,
-        #    self.BlogPost.objects(comments__author='user4')[0].comments
-        # )
-        self.assertTrue(
-            comment in self.BlogPost.objects(
-                comments__author='user4'
-            )[0].comments
+        self.assertIn(
+            comment,
+            self.BlogPost.objects(comments__author='user4')[0].comments
         )
 
     def test_no_keyword_update(self):
@@ -4114,22 +4057,14 @@ class EmbeddedDocumentListFieldTestCase(unittest.TestCase):
         self.post1.save()
 
         # Ensure that nothing was altered.
-        # < 2.6 Incompatible >
-        # self.assertIn(
-        #    original[0],
-        #    self.BlogPost.objects(id=self.post1.id)[0].comments
-        # )
-        self.assertTrue(
-            original[0] in self.BlogPost.objects(id=self.post1.id)[0].comments
+        self.assertIn(
+            original[0],
+            self.BlogPost.objects(id=self.post1.id)[0].comments
         )
 
-        # < 2.6 Incompatible >
-        # self.assertIn(
-        #    original[1],
-        #    self.BlogPost.objects(id=self.post1.id)[0].comments
-        # )
-        self.assertTrue(
-            original[1] in self.BlogPost.objects(id=self.post1.id)[0].comments
+        self.assertIn(
+            original[1],
+            self.BlogPost.objects(id=self.post1.id)[0].comments
         )
 
         # Ensure the method returned 0 as the number of entries
@@ -4175,13 +4110,9 @@ class EmbeddedDocumentListFieldTestCase(unittest.TestCase):
         comments.save()
 
         # Ensure that the new comment has been added to the database.
-        # < 2.6 Incompatible >
-        # self.assertIn(
-        #    new_comment,
-        #    self.BlogPost.objects(id=self.post1.id)[0].comments
-        # )
-        self.assertTrue(
-            new_comment in self.BlogPost.objects(id=self.post1.id)[0].comments
+        self.assertIn(
+            new_comment,
+            self.BlogPost.objects(id=self.post1.id)[0].comments
         )
 
     def test_delete(self):
@@ -4193,23 +4124,15 @@ class EmbeddedDocumentListFieldTestCase(unittest.TestCase):
 
         # Ensure that all the comments under post1 were deleted in the
         # database.
-        # < 2.6 Incompatible >
-        # self.assertListEqual(
-        #    self.BlogPost.objects(id=self.post1.id)[0].comments, []
-        # )
-        self.assertEqual(
+        self.assertListEqual(
             self.BlogPost.objects(id=self.post1.id)[0].comments, []
         )
 
         # Ensure that post1 comments were deleted from the list.
-        # < 2.6 Incompatible >
-        # self.assertListEqual(self.post1.comments, [])
-        self.assertEqual(self.post1.comments, [])
+        self.assertListEqual(self.post1.comments, [])
 
         # Ensure that comments still returned a EmbeddedDocumentList object.
-        # < 2.6 Incompatible >
-        # self.assertIsInstance(self.post1.comments, EmbeddedDocumentList)
-        self.assertTrue(isinstance(self.post1.comments, EmbeddedDocumentList))
+        self.assertIsInstance(self.post1.comments, EmbeddedDocumentList)
 
         # Ensure that the delete method returned 2 as the number of entries
         # deleted from the database
@@ -4249,21 +4172,15 @@ class EmbeddedDocumentListFieldTestCase(unittest.TestCase):
         self.post1.save()
 
         # Ensure that only the user2 comment was deleted.
-        # < 2.6 Incompatible >
-        # self.assertNotIn(
-        #     comment, self.BlogPost.objects(id=self.post1.id)[0].comments
-        # )
-        self.assertTrue(
-            comment not in self.BlogPost.objects(id=self.post1.id)[0].comments
+        self.assertNotIn(
+            comment, self.BlogPost.objects(id=self.post1.id)[0].comments
         )
         self.assertEqual(
             len(self.BlogPost.objects(id=self.post1.id)[0].comments), 1
         )
 
         # Ensure that the user2 comment no longer exists in the list.
-        # < 2.6 Incompatible >
-        # self.assertNotIn(comment, self.post1.comments)
-        self.assertTrue(comment not in self.post1.comments)
+        self.assertNotIn(comment, self.post1.comments)
         self.assertEqual(len(self.post1.comments), 1)
 
         # Ensure that the delete method returned 1 as the number of entries
diff --git a/tests/queryset/queryset.py b/tests/queryset/queryset.py
index a56b6c26..e4c71de7 100644
--- a/tests/queryset/queryset.py
+++ b/tests/queryset/queryset.py
@@ -25,7 +25,10 @@ __all__ = ("QuerySetTest",)
 class db_ops_tracker(query_counter):
 
     def get_ops(self):
-        ignore_query = {"ns": {"$ne": "%s.system.indexes" % self.db.name}}
+        ignore_query = {
+            'ns': {'$ne': '%s.system.indexes' % self.db.name},
+            'command.count': {'$ne': 'system.profile'}
+        }
         return list(self.db.system.profile.find(ignore_query))
 
 
@@ -94,12 +97,12 @@ class QuerySetTest(unittest.TestCase):
             author = ReferenceField(self.Person)
             author2 = GenericReferenceField()
 
-        def test_reference():
+        # test addressing a field from a reference
+        with self.assertRaises(InvalidQueryError):
             list(BlogPost.objects(author__name="test"))
 
-        self.assertRaises(InvalidQueryError, test_reference)
-
-        def test_generic_reference():
+        # should fail for a generic reference as well
+        with self.assertRaises(InvalidQueryError):
             list(BlogPost.objects(author2__name="test"))
 
     def test_find(self):
@@ -218,14 +221,15 @@ class QuerySetTest(unittest.TestCase):
         person = self.Person.objects[1]
         self.assertEqual(person.name, "User B")
 
-        self.assertRaises(IndexError, self.Person.objects.__getitem__, 2)
+        with self.assertRaises(IndexError):
+            self.Person.objects[2]
 
         # Find a document using just the object id
         person = self.Person.objects.with_id(person1.id)
         self.assertEqual(person.name, "User A")
 
-        self.assertRaises(
-            InvalidQueryError, self.Person.objects(name="User A").with_id, person1.id)
+        with self.assertRaises(InvalidQueryError):
+            self.Person.objects(name="User A").with_id(person1.id)
 
     def test_find_only_one(self):
         """Ensure that a query using ``get`` returns at most one result.
@@ -363,7 +367,8 @@ class QuerySetTest(unittest.TestCase):
 
         # test invalid batch size
         qs = A.objects.batch_size(-1)
-        self.assertRaises(ValueError, lambda: list(qs))
+        with self.assertRaises(ValueError):
+            list(qs)
 
     def test_update_write_concern(self):
         """Test that passing write_concern works"""
@@ -392,18 +397,14 @@ class QuerySetTest(unittest.TestCase):
         """Test to ensure that update is passed a value to update to"""
         self.Person.drop_collection()
 
-        author = self.Person(name='Test User')
-        author.save()
+        author = self.Person.objects.create(name='Test User')
 
-        def update_raises():
+        with self.assertRaises(OperationError):
             self.Person.objects(pk=author.pk).update({})
 
-        def update_one_raises():
+        with self.assertRaises(OperationError):
             self.Person.objects(pk=author.pk).update_one({})
 
-        self.assertRaises(OperationError, update_raises)
-        self.assertRaises(OperationError, update_one_raises)
-
     def test_update_array_position(self):
         """Ensure that updating by array position works.
 
@@ -431,8 +432,8 @@ class QuerySetTest(unittest.TestCase):
         Blog.objects.create(posts=[post2, post1])
 
         # Update all of the first comments of second posts of all blogs
-        Blog.objects().update(set__posts__1__comments__0__name="testc")
-        testc_blogs = Blog.objects(posts__1__comments__0__name="testc")
+        Blog.objects().update(set__posts__1__comments__0__name='testc')
+        testc_blogs = Blog.objects(posts__1__comments__0__name='testc')
         self.assertEqual(testc_blogs.count(), 2)
 
         Blog.drop_collection()
@@ -441,14 +442,13 @@ class QuerySetTest(unittest.TestCase):
 
         # Update only the first blog returned by the query
         Blog.objects().update_one(
-            set__posts__1__comments__1__name="testc")
-        testc_blogs = Blog.objects(posts__1__comments__1__name="testc")
+            set__posts__1__comments__1__name='testc')
+        testc_blogs = Blog.objects(posts__1__comments__1__name='testc')
         self.assertEqual(testc_blogs.count(), 1)
 
         # Check that using this indexing syntax on a non-list fails
-        def non_list_indexing():
-            Blog.objects().update(set__posts__1__comments__0__name__1="asdf")
-        self.assertRaises(InvalidQueryError, non_list_indexing)
+        with self.assertRaises(InvalidQueryError):
+            Blog.objects().update(set__posts__1__comments__0__name__1='asdf')
 
         Blog.drop_collection()
 
@@ -516,15 +516,12 @@ class QuerySetTest(unittest.TestCase):
         self.assertEqual(simple.x, [1, 2, None, 4, 3, 2, 3, 4])
 
         # Nested updates arent supported yet..
-        def update_nested():
+        with self.assertRaises(OperationError):
             Simple.drop_collection()
             Simple(x=[{'test': [1, 2, 3, 4]}]).save()
             Simple.objects(x__test=2).update(set__x__S__test__S=3)
             self.assertEqual(simple.x, [1, 2, 3, 4])
 
-        self.assertRaises(OperationError, update_nested)
-        Simple.drop_collection()
-
     def test_update_using_positional_operator_embedded_document(self):
         """Ensure that the embedded documents can be updated using the positional
         operator."""
@@ -839,30 +836,31 @@ class QuerySetTest(unittest.TestCase):
 
         self.assertEqual(Blog.objects.count(), 2)
 
-        # test handles people trying to upsert
-        def throw_operation_error():
+        # test inserting an existing document (shouldn't be allowed)
+        with self.assertRaises(OperationError):
+            blog = Blog.objects.first()
+            Blog.objects.insert(blog)
+
+        # test inserting a query set
+        with self.assertRaises(OperationError):
             blogs = Blog.objects
             Blog.objects.insert(blogs)
 
-        self.assertRaises(OperationError, throw_operation_error)
-
-        # Test can insert new doc
+        # insert a new doc
         new_post = Blog(title="code123", id=ObjectId())
         Blog.objects.insert(new_post)
 
-        # test handles other classes being inserted
-        def throw_operation_error_wrong_doc():
-            class Author(Document):
-                pass
+        class Author(Document):
+            pass
+
+        # try inserting a different document class
+        with self.assertRaises(OperationError):
             Blog.objects.insert(Author())
 
-        self.assertRaises(OperationError, throw_operation_error_wrong_doc)
-
-        def throw_operation_error_not_a_document():
+        # try inserting a non-document
+        with self.assertRaises(OperationError):
             Blog.objects.insert("HELLO WORLD")
 
-        self.assertRaises(OperationError, throw_operation_error_not_a_document)
-
         Blog.drop_collection()
 
         blog1 = Blog(title="code", posts=[post1, post2])
@@ -882,14 +880,13 @@ class QuerySetTest(unittest.TestCase):
         blog3 = Blog(title="baz", posts=[post1, post2])
         Blog.objects.insert([blog1, blog2])
 
-        def throw_operation_error_not_unique():
+        with self.assertRaises(NotUniqueError):
             Blog.objects.insert([blog2, blog3])
 
-        self.assertRaises(NotUniqueError, throw_operation_error_not_unique)
         self.assertEqual(Blog.objects.count(), 2)
 
-        Blog.objects.insert([blog2, blog3], write_concern={"w": 0,
-                                                           'continue_on_error': True})
+        Blog.objects.insert([blog2, blog3],
+                            write_concern={"w": 0, 'continue_on_error': True})
         self.assertEqual(Blog.objects.count(), 3)
 
     def test_get_changed_fields_query_count(self):
@@ -1233,7 +1230,9 @@ class QuerySetTest(unittest.TestCase):
             BlogPost.objects.filter(title='whatever').first()
             self.assertEqual(len(q.get_ops()), 1)
             self.assertEqual(
-                q.get_ops()[0]['query']['$orderby'], {u'published_date': -1})
+                q.get_ops()[0]['query']['$orderby'],
+                {'published_date': -1}
+            )
 
         with db_ops_tracker() as q:
             BlogPost.objects.filter(title='whatever').order_by().first()
@@ -1910,12 +1909,10 @@ class QuerySetTest(unittest.TestCase):
         Site.objects(id=s.id).update_one(pull__collaborators__user='Esteban')
         self.assertEqual(Site.objects.first().collaborators, [])
 
-        def pull_all():
+        with self.assertRaises(InvalidQueryError):
             Site.objects(id=s.id).update_one(
                 pull_all__collaborators__user=['Ross'])
 
-        self.assertRaises(InvalidQueryError, pull_all)
-
     def test_pull_from_nested_embedded(self):
 
         class User(EmbeddedDocument):
@@ -1946,12 +1943,10 @@ class QuerySetTest(unittest.TestCase):
             pull__collaborators__unhelpful={'name': 'Frank'})
         self.assertEqual(Site.objects.first().collaborators['unhelpful'], [])
 
-        def pull_all():
+        with self.assertRaises(InvalidQueryError):
             Site.objects(id=s.id).update_one(
                 pull_all__collaborators__helpful__name=['Ross'])
 
-        self.assertRaises(InvalidQueryError, pull_all)
-
     def test_pull_from_nested_mapfield(self):
 
         class Collaborator(EmbeddedDocument):
@@ -1980,12 +1975,10 @@ class QuerySetTest(unittest.TestCase):
             pull__collaborators__unhelpful={'user': 'Frank'})
         self.assertEqual(Site.objects.first().collaborators['unhelpful'], [])
 
-        def pull_all():
+        with self.assertRaises(InvalidQueryError):
             Site.objects(id=s.id).update_one(
                 pull_all__collaborators__helpful__user=['Ross'])
 
-        self.assertRaises(InvalidQueryError, pull_all)
-
     def test_update_one_pop_generic_reference(self):
 
         class BlogTag(Document):
@@ -3821,11 +3814,9 @@ class QuerySetTest(unittest.TestCase):
         self.assertTrue(a in results)
         self.assertTrue(c in results)
 
-        def invalid_where():
+        with self.assertRaises(TypeError):
             list(IntPair.objects.where(fielda__gte=3))
 
-        self.assertRaises(TypeError, invalid_where)
-
     def test_scalar(self):
 
         class Organization(Document):
@@ -4550,7 +4541,9 @@ class QuerySetTest(unittest.TestCase):
         self.assertEqual(counter, 100)
 
         self.assertEqual(len(list(docs)), 100)
-        self.assertRaises(TypeError, lambda: len(docs))
+
+        with self.assertRaises(TypeError):
+            len(docs)
 
         with query_counter() as q:
             self.assertEqual(q, 0)
@@ -4875,7 +4868,9 @@ class QuerySetTest(unittest.TestCase):
 
     def test_max_time_ms(self):
         # 778: max_time_ms can get only int or None as input
-        self.assertRaises(TypeError, self.Person.objects(name="name").max_time_ms, "not a number")
+        self.assertRaises(TypeError,
+                          self.Person.objects(name="name").max_time_ms,
+                          'not a number')
 
     def test_subclass_field_query(self):
         class Animal(Document):
diff --git a/tests/queryset/transform.py b/tests/queryset/transform.py
index 06fe4ea5..20ab0b3f 100644
--- a/tests/queryset/transform.py
+++ b/tests/queryset/transform.py
@@ -238,7 +238,8 @@ class TransformTest(unittest.TestCase):
         box = [(35.0, -125.0), (40.0, -100.0)]
         # I *meant* to execute location__within_box=box
         events = Event.objects(location__within=box)
-        self.assertRaises(InvalidQueryError, lambda: events.count())
+        with self.assertRaises(InvalidQueryError):
+            events.count()
 
 
 if __name__ == '__main__':
diff --git a/tests/queryset/visitor.py b/tests/queryset/visitor.py
index ee2ef59a..6f020e88 100644
--- a/tests/queryset/visitor.py
+++ b/tests/queryset/visitor.py
@@ -268,14 +268,13 @@ class QTest(unittest.TestCase):
         self.assertEqual(self.Person.objects(Q(age__in=[20, 30])).count(), 3)
 
         # Test invalid query objs
-        def wrong_query_objs():
+        with self.assertRaises(InvalidQueryError):
             self.Person.objects('user1')
 
-        def wrong_query_objs_filter():
-            self.Person.objects('user1')
+        # filter should fail, too
+        with self.assertRaises(InvalidQueryError):
+            self.Person.objects.filter('user1')
 
-        self.assertRaises(InvalidQueryError, wrong_query_objs)
-        self.assertRaises(InvalidQueryError, wrong_query_objs_filter)
 
     def test_q_regex(self):
         """Ensure that Q objects can be queried using regexes.
diff --git a/tests/test_datastructures.py b/tests/test_datastructures.py
index eb40e767..6830a188 100644
--- a/tests/test_datastructures.py
+++ b/tests/test_datastructures.py
@@ -23,7 +23,8 @@ class TestStrictDict(unittest.TestCase):
         self.assertEqual(repr(d), '{"a": \'"\', "b": "\'", "c": \'\'}')
 
     def test_init_fails_on_nonexisting_attrs(self):
-        self.assertRaises(AttributeError, lambda: self.dtype(a=1, b=2, d=3))
+        with self.assertRaises(AttributeError):
+            self.dtype(a=1, b=2, d=3)
 
     def test_eq(self):
         d = self.dtype(a=1, b=1, c=1)
@@ -46,14 +47,12 @@ class TestStrictDict(unittest.TestCase):
         d = self.dtype()
         d.a = 1
         self.assertEqual(d.a, 1)
-        self.assertRaises(AttributeError, lambda: d.b)
+        self.assertRaises(AttributeError, getattr, d, 'b')
 
     def test_setattr_raises_on_nonexisting_attr(self):
         d = self.dtype()
-
-        def _f():
+        with self.assertRaises(AttributeError):
             d.x = 1
-        self.assertRaises(AttributeError, _f)
 
     def test_setattr_getattr_special(self):
         d = self.strict_dict_class(["items"])