include a link to PyMongo docs for batch_size

mongoengine/base/datastructures.py

@@ -438,7 +438,7 @@ class StrictDict(object):
                 __slots__ = allowed_keys_tuple
 
                 def __repr__(self):
-                    return "{%s}" % ', '.join('"{0!s}": {0!r}'.format(k) for k in self.iterkeys())
+                    return "{%s}" % ', '.join('"{0!s}": {1!r}'.format(k, v) for k, v in self.items())
 
             cls._classes[allowed_keys] = SpecificStrictDict
         return cls._classes[allowed_keys]

mongoengine/fields.py

@@ -577,7 +577,7 @@ class EmbeddedDocumentField(BaseField):
         return self.document_type._fields.get(member_name)
 
     def prepare_query_value(self, op, value):
-        if not isinstance(value, self.document_type):
+        if value is not None and not isinstance(value, self.document_type):
             value = self.document_type._from_son(value)
         super(EmbeddedDocumentField, self).prepare_query_value(op, value)
         return self.to_mongo(value)

mongoengine/queryset/base.py

@@ -82,6 +82,7 @@ class BaseQuerySet(object):
         self._limit = None
         self._skip = None
         self._hint = -1  # Using -1 as None is a valid value for hint
+        self._batch_size = None
         self.only_fields = []
         self._max_time_ms = None
 
@@ -781,6 +782,19 @@ class BaseQuerySet(object):
         queryset._hint = index
         return queryset
 
+    def batch_size(self, size):
+        """Limit the number of documents returned in a single batch (each
+        batch requires a round trip to the server).
+
+        See http://api.mongodb.com/python/current/api/pymongo/cursor.html#pymongo.cursor.Cursor.batch_size
+        for details.
+
+        :param size: desired size of each batch.
+        """
+        queryset = self.clone()
+        queryset._batch_size = size
+        return queryset
+
     def distinct(self, field):
         """Return a list of distinct values for a given field.
 
@@ -933,6 +947,14 @@ class BaseQuerySet(object):
         queryset._ordering = queryset._get_order_by(keys)
         return queryset
 
+    def comment(self, text):
+        """Add a comment to the query.
+
+        See https://docs.mongodb.com/manual/reference/method/cursor.comment/#cursor.comment
+        for details.
+        """
+        return self._chainable_method("comment", text)
+
     def explain(self, format=False):
         """Return an explain plan record for the
         :class:`~mongoengine.queryset.QuerySet`\ 's cursor.
@@ -1459,6 +1481,9 @@ class BaseQuerySet(object):
             if self._hint != -1:
                 self._cursor_obj.hint(self._hint)
 
+            if self._batch_size is not None:
+                self._cursor_obj.batch_size(self._batch_size)
+
         return self._cursor_obj
 
     def __deepcopy__(self, memo):

tests/document/indexes.py

@@ -2,10 +2,8 @@
 import unittest
 import sys
 
-sys.path[0:0] = [""]
 
 import pymongo
-from random import randint
 
 from nose.plugins.skip import SkipTest
 from datetime import datetime
@@ -17,11 +15,9 @@ __all__ = ("IndexesTest", )
 
 
 class IndexesTest(unittest.TestCase):
-    _MAX_RAND = 10 ** 10
 
     def setUp(self):
-        self.db_name = 'mongoenginetest_IndexesTest_' + str(randint(0, self._MAX_RAND))
-        self.connection = connect(db=self.db_name)
+        self.connection = connect(db='mongoenginetest')
         self.db = get_db()
 
         class Person(Document):

tests/queryset/queryset.py

@@ -337,9 +337,36 @@ class QuerySetTest(unittest.TestCase):
         query = query.filter(boolfield=True)
         self.assertEqual(query.count(), 1)
 
+    def test_batch_size(self):
+        """Ensure that batch_size works."""
+        class A(Document):
+            s = StringField()
+
+        A.drop_collection()
+
+        for i in range(100):
+            A.objects.create(s=str(i))
+
+        # test iterating over the result set
+        cnt = 0
+        for a in A.objects.batch_size(10):
+            cnt += 1
+        self.assertEqual(cnt, 100)
+
+        # test chaining
+        qs = A.objects.all()
+        qs = qs.limit(10).batch_size(20).skip(91)
+        cnt = 0
+        for a in qs:
+            cnt += 1
+        self.assertEqual(cnt, 9)
+
+        # test invalid batch size
+        qs = A.objects.batch_size(-1)
+        self.assertRaises(ValueError, lambda: list(qs))
+
     def test_update_write_concern(self):
         """Test that passing write_concern works"""
-
         self.Person.drop_collection()
 
         write_concern = {"fsync": True}
@@ -1239,7 +1266,8 @@ class QuerySetTest(unittest.TestCase):
             self.assertFalse('$orderby' in q.get_ops()[0]['query'])
 
     def test_find_embedded(self):
-        """Ensure that an embedded document is properly returned from a query.
+        """Ensure that an embedded document is properly returned from
+        a query.
         """
         class User(EmbeddedDocument):
             name = StringField()
@@ -1250,16 +1278,31 @@ class QuerySetTest(unittest.TestCase):
 
         BlogPost.drop_collection()
 
-        post = BlogPost(content='Had a good coffee today...')
-        post.author = User(name='Test User')
-        post.save()
+        BlogPost.objects.create(
+            author=User(name='Test User'),
+            content='Had a good coffee today...'
+        )
 
         result = BlogPost.objects.first()
         self.assertTrue(isinstance(result.author, User))
         self.assertEqual(result.author.name, 'Test User')
 
+    def test_find_empty_embedded(self):
+        """Ensure that you can save and find an empty embedded document."""
+        class User(EmbeddedDocument):
+            name = StringField()
+
+        class BlogPost(Document):
+            content = StringField()
+            author = EmbeddedDocumentField(User)
+
         BlogPost.drop_collection()
 
+        BlogPost.objects.create(content='Anonymous post...')
+
+        result = BlogPost.objects.get(author=None)
+        self.assertEqual(result.author, None)
+
     def test_find_dict_item(self):
         """Ensure that DictField items may be found.
         """
@@ -2199,6 +2242,21 @@ class QuerySetTest(unittest.TestCase):
             a.author.name for a in Author.objects.order_by('-author__age')]
         self.assertEqual(names, ['User A', 'User B', 'User C'])
 
+    def test_comment(self):
+        """Make sure adding a comment to the query works."""
+        class User(Document):
+            age = IntField()
+
+        with db_ops_tracker() as q:
+            adult = (User.objects.filter(age__gte=18)
+                .comment('looking for an adult')
+                .first())
+            ops = q.get_ops()
+            self.assertEqual(len(ops), 1)
+            op = ops[0]
+            self.assertEqual(op['query']['$query'], {'age': {'$gte': 18}})
+            self.assertEqual(op['query']['$comment'], 'looking for an adult')
+
     def test_map_reduce(self):
         """Ensure map/reduce is both mapping and reducing.
         """

tests/test_datastructures.py

@@ -1,5 +1,6 @@
 import unittest
-from mongoengine.base.datastructures import StrictDict, SemiStrictDict 
+
+from mongoengine.base.datastructures import StrictDict, SemiStrictDict
 
 
 class TestStrictDict(unittest.TestCase):
@@ -13,9 +14,17 @@ class TestStrictDict(unittest.TestCase):
         d = self.dtype(a=1, b=1, c=1)
         self.assertEqual((d.a, d.b, d.c), (1, 1, 1))
 
+    def test_repr(self):
+        d = self.dtype(a=1, b=2, c=3)
+        self.assertEqual(repr(d), '{"a": 1, "b": 2, "c": 3}')
+
+        # make sure quotes are escaped properly
+        d = self.dtype(a='"', b="'", c="")
+        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))
-        
+
     def test_eq(self):
         d = self.dtype(a=1, b=1, c=1)
         dd = self.dtype(a=1, b=1, c=1)
@@ -24,7 +33,7 @@ class TestStrictDict(unittest.TestCase):
         g = self.strict_dict_class(("a", "b", "c", "d"))(a=1, b=1, c=1, d=1)
         h = self.strict_dict_class(("a", "c", "b"))(a=1, b=1, c=1)
         i = self.strict_dict_class(("a", "c", "b"))(a=1, b=1, c=2)
-        
+
         self.assertEqual(d, dd)
         self.assertNotEqual(d, e)
         self.assertNotEqual(d, f)
@@ -38,19 +47,19 @@ class TestStrictDict(unittest.TestCase):
         d.a = 1
         self.assertEqual(d.a, 1)
         self.assertRaises(AttributeError, lambda: d.b)
-    
+
     def test_setattr_raises_on_nonexisting_attr(self):
         d = self.dtype()
 
         def _f():
             d.x = 1
         self.assertRaises(AttributeError, _f)
-    
+
     def test_setattr_getattr_special(self):
         d = self.strict_dict_class(["items"])
         d.items = 1
         self.assertEqual(d.items, 1)
-    
+
     def test_get(self):
         d = self.dtype(a=1)
         self.assertEqual(d.get('a'), 1)
@@ -88,7 +97,7 @@ class TestSemiSrictDict(TestStrictDict):
     def test_init_succeeds_with_nonexisting_attrs(self):
         d = self.dtype(a=1, b=1, c=1, x=2)
         self.assertEqual((d.a, d.b, d.c, d.x), (1, 1, 1, 2))
-   
+
     def test_iter_with_nonexisting_attrs(self):
         d = self.dtype(a=1, b=1, c=1, x=2)
         self.assertEqual(list(d), ['a', 'b', 'c', 'x'])