PYTHON-1323 Removed Collection.group (#559)

Author: ShaneHarvey

doc/api/pymongo/collection.rst

@@ -69,5 +69,4 @@
       .. automethod:: inline_map_reduce
       .. automethod:: initialize_unordered_bulk_op
       .. automethod:: initialize_ordered_bulk_op
-      .. automethod:: group
       .. automethod:: count

doc/changelog.rst

@@ -35,6 +35,7 @@ Breaking Changes in 4.0
 - Removed :meth:`pymongo.collection.Collection.update`.
 - Removed :meth:`pymongo.collection.Collection.remove`.
 - Removed :meth:`pymongo.collection.Collection.find_and_modify`.
+- Removed :meth:`pymongo.collection.Collection.group`.
 - Removed :meth:`pymongo.mongo_client.MongoClient.close_cursor`. Use
   :meth:`pymongo.cursor.Cursor.close` instead.
 - Removed :meth:`pymongo.mongo_client.MongoClient.kill_cursors`.

doc/migrate-to-pymongo4.rst

@@ -237,6 +237,16 @@ Can be changed to this::
   replaced_doc = collection.find_one_and_replace({'b': 1}, {'c': 1})
   deleted_doc = collection.find_one_and_delete({'c': 1})
 
+Collection.group is removed
+...........................
+
+Removed :meth:`pymongo.collection.Collection.group`. This method was
+deprecated in PyMongo 3.5. MongoDB 4.2 removed the `group command`_.
+Use :meth:`~pymongo.collection.Collection.aggregate` with the ``$group`` stage
+instead.
+
+.. _group command: https://docs.mongodb.com/manual/reference/command/group/
+
 Collection.ensure_index is removed
 ..................................
 

pymongo/collection.py

@@ -2366,46 +2366,6 @@ def watch(self, pipeline=None, full_document=None, resume_after=None,
             batch_size, collation, start_at_operation_time, session,
             start_after)
 
-    def group(self, key, condition, initial, reduce, finalize=None, **kwargs):
-        """Perform a query similar to an SQL *group by* operation.
-
-        **DEPRECATED** - The group command was deprecated in MongoDB 3.4. The
-        :meth:`~group` method is deprecated and will be removed in PyMongo 4.0.
-        Use :meth:`~aggregate` with the `$group` stage or :meth:`~map_reduce`
-        instead.
-
-        .. versionchanged:: 3.5
-           Deprecated the group method.
-        .. versionchanged:: 3.4
-           Added the `collation` option.
-        .. versionchanged:: 2.2
-           Removed deprecated argument: command
-        """
-        warnings.warn("The group method is deprecated and will be removed in "
-                      "PyMongo 4.0. Use the aggregate method with the $group "
-                      "stage or the map_reduce method instead.",
-                      DeprecationWarning, stacklevel=2)
-        group = {}
-        if isinstance(key, str):
-            group["$keyf"] = Code(key)
-        elif key is not None:
-            group = {"key": helpers._fields_list_to_dict(key, "key")}
-        group["ns"] = self.__name
-        group["$reduce"] = Code(reduce)
-        group["cond"] = condition
-        group["initial"] = initial
-        if finalize is not None:
-            group["finalize"] = Code(finalize)
-
-        cmd = SON([("group", group)])
-        collation = validate_collation_or_none(kwargs.pop('collation', None))
-        cmd.update(kwargs)
-
-        with self._socket_for_reads(session=None) as (sock_info, slave_ok):
-            return self._command(sock_info, cmd, slave_ok,
-                                 collation=collation,
-                                 user_fields={'retval': 1})["retval"]
-
     def rename(self, new_name, session=None, **kwargs):
         """Rename this collection.
 

test/test_collation.py

@@ -188,14 +188,6 @@ def test_explain_command(self):
             self.collation.document,
             self.last_command_started()['explain']['collation'])
 
-    @raisesConfigurationErrorForOldMongoDB
-    @client_context.require_version_max(4, 1, 0, -1)
-    def test_group(self):
-        self.db.test.group('foo', {'foo': {'$gt': 42}}, {},
-                           'function(a, b) { return a; }',
-                           collation=self.collation)
-        self.assertCollationInLastCommand()
-
     @raisesConfigurationErrorForOldMongoDB
     def test_map_reduce(self):
         self.db.test.map_reduce('function() {}', 'function() {}', 'output',

test/test_custom_types.py

@@ -588,19 +588,6 @@ def run_test(doc_cls):
         for doc_cls in [RawBSONDocument, OrderedDict]:
             run_test(doc_cls)
 
-    @client_context.require_version_max(4, 1, 0, -1)
-    def test_group_w_custom_type(self):
-        db = self.db
-        test = db.get_collection('test', codec_options=UNINT_CODECOPTS)
-        test.insert_many([
-            {'sku': 'a', 'qty': UndecipherableInt64Type(2)},
-            {'sku': 'b', 'qty': UndecipherableInt64Type(5)},
-            {'sku': 'a', 'qty': UndecipherableInt64Type(1)}])
-
-        self.assertEqual([{'sku': 'b', 'qty': UndecipherableInt64Type(5)},],
-                         test.group(["sku", "qty"], {"sku": "b"}, {},
-                                    "function (obj, prev) { }"))
-
     def test_aggregate_w_custom_type_decoder(self):
         db = self.db
         db.test.insert_many([

test/test_legacy_api.py

@@ -74,124 +74,6 @@ def setUpClass(cls):
     def tearDownClass(cls):
         cls.deprecation_filter.stop()
 
-    @client_context.require_version_max(4, 1, 0, -1)
-    def test_group(self):
-        db = self.db
-        db.drop_collection("test")
-
-        self.assertEqual([],
-                         db.test.group([], {}, {"count": 0},
-                                       "function (obj, prev) { prev.count++; }"
-                                      ))
-
-        db.test.insert_many([{"a": 2}, {"b": 5}, {"a": 1}])
-
-        self.assertEqual([{"count": 3}],
-                         db.test.group([], {}, {"count": 0},
-                                       "function (obj, prev) { prev.count++; }"
-                                      ))
-
-        self.assertEqual([{"count": 1}],
-                         db.test.group([], {"a": {"$gt": 1}}, {"count": 0},
-                                       "function (obj, prev) { prev.count++; }"
-                                      ))
-
-        db.test.insert_one({"a": 2, "b": 3})
-
-        self.assertEqual([{"a": 2, "count": 2},
-                          {"a": None, "count": 1},
-                          {"a": 1, "count": 1}],
-                         db.test.group(["a"], {}, {"count": 0},
-                                       "function (obj, prev) { prev.count++; }"
-                                      ))
-
-        # modifying finalize
-        self.assertEqual([{"a": 2, "count": 3},
-                          {"a": None, "count": 2},
-                          {"a": 1, "count": 2}],
-                         db.test.group(["a"], {}, {"count": 0},
-                                       "function (obj, prev) "
-                                       "{ prev.count++; }",
-                                       "function (obj) { obj.count++; }"))
-
-        # returning finalize
-        self.assertEqual([2, 1, 1],
-                         db.test.group(["a"], {}, {"count": 0},
-                                       "function (obj, prev) "
-                                       "{ prev.count++; }",
-                                       "function (obj) { return obj.count; }"))
-
-        # keyf
-        self.assertEqual([2, 2],
-                         db.test.group("function (obj) { if (obj.a == 2) "
-                                       "{ return {a: true} }; "
-                                       "return {b: true}; }", {}, {"count": 0},
-                                       "function (obj, prev) "
-                                       "{ prev.count++; }",
-                                       "function (obj) { return obj.count; }"))
-
-        # no key
-        self.assertEqual([{"count": 4}],
-                         db.test.group(None, {}, {"count": 0},
-                                       "function (obj, prev) { prev.count++; }"
-                                      ))
-
-        self.assertRaises(OperationFailure, db.test.group,
-                          [], {}, {}, "5 ++ 5")
-
-    @client_context.require_version_max(4, 1, 0, -1)
-    def test_group_with_scope(self):
-        db = self.db
-        db.drop_collection("test")
-        db.test.insert_many([{"a": 1}, {"b": 1}])
-
-        reduce_function = "function (obj, prev) { prev.count += inc_value; }"
-
-        self.assertEqual(2, db.test.group([], {}, {"count": 0},
-                                          Code(reduce_function,
-                                               {"inc_value": 1}))[0]['count'])
-        self.assertEqual(4, db.test.group([], {}, {"count": 0},
-                                          Code(reduce_function,
-                                               {"inc_value": 2}))[0]['count'])
-
-        self.assertEqual(1,
-                         db.test.group([], {}, {"count": 0},
-                                       Code(reduce_function,
-                                            {"inc_value": 0.5}))[0]['count'])
-
-        self.assertEqual(2, db.test.group(
-            [], {}, {"count": 0},
-            Code(reduce_function, {"inc_value": 1}))[0]['count'])
-
-        self.assertEqual(4, db.test.group(
-            [], {}, {"count": 0},
-            Code(reduce_function, {"inc_value": 2}))[0]['count'])
-
-        self.assertEqual(1, db.test.group(
-            [], {}, {"count": 0},
-            Code(reduce_function, {"inc_value": 0.5}))[0]['count'])
-
-    @client_context.require_version_max(4, 1, 0, -1)
-    def test_group_uuid_representation(self):
-        db = self.db
-        coll = db.uuid
-        coll.drop()
-        uu = uuid.uuid4()
-        coll.insert_one({"_id": uu, "a": 2})
-        coll.insert_one({"_id": uuid.uuid4(), "a": 1})
-
-        reduce = "function (obj, prev) { prev.count++; }"
-        coll = self.db.get_collection(
-            "uuid", CodecOptions(uuid_representation=STANDARD))
-        self.assertEqual([],
-                         coll.group([], {"_id": uu},
-                                    {"count": 0}, reduce))
-        coll = self.db.get_collection(
-            "uuid", CodecOptions(uuid_representation=PYTHON_LEGACY))
-        self.assertEqual([{"count": 1}],
-                         coll.group([], {"_id": uu},
-                                    {"count": 0}, reduce))
-
 
 class TestLegacyBulk(BulkTestBase):
 

test/test_read_preferences.py

@@ -360,7 +360,7 @@ def setUpClass(cls):
         if client_context.auth_enabled:
             cls.c.admin.authenticate(db_user, db_pwd)
         cls.client_version = Version.from_client(cls.c)
-        # mapReduce and group fail with no collection
+        # mapReduce fails if the collection does not exist.
         coll = cls.c.pymongo_test.get_collection(
             'test', write_concern=WriteConcern(w=client_context.w))
         coll.insert_one({})
@@ -431,13 +431,6 @@ def test_create_collection(self):
             lambda: self.c.pymongo_test.create_collection(
                 'some_collection%s' % random.randint(0, sys.maxsize)))
 
-    @client_context.require_version_max(4, 1, 0, -1)
-    def test_group(self):
-        with warnings.catch_warnings():
-            warnings.simplefilter("ignore")
-            self._test_coll_helper(True, self.c.pymongo_test.test, 'group',
-                                   {'a': 1}, {}, {}, 'function() { }')
-
     def test_map_reduce(self):
         self._test_coll_helper(False, self.c.pymongo_test.test, 'map_reduce',
                                'function() { }', 'function() { }',