fix linting + update changelog & contributors

AUTHORS

@@ -256,3 +256,4 @@ that much better:
  * Eric Timmons (https://github.com/daewok)
  * Matthew Simpson (https://github.com/mcsimps2)
  * Leonardo Domingues (https://github.com/leodmgs)
+ * Agustin Barto (https://github.com/abarto)

docs/changelog.rst

@@ -21,6 +21,7 @@ Development
     - ``Queryset._ensure_indexes`` and ``Queryset.ensure_indexes``, the right method to use is ``Document.ensure_indexes``
 - Added pre-commit #2212
 - Renamed requirements-lint.txt to requirements-dev.txt #2212
+- Support for setting ReadConcern #2255
 
 Changes in 0.19.1
 =================

mongoengine/context_managers.py

@@ -1,7 +1,7 @@
 from contextlib import contextmanager
 
-from pymongo.write_concern import WriteConcern
 from pymongo.read_concern import ReadConcern
+from pymongo.write_concern import WriteConcern
 
 from mongoengine.common import _import_class
 from mongoengine.connection import DEFAULT_CONNECTION_NAME, get_db
@@ -268,11 +268,11 @@ def set_read_write_concern(collection, write_concerns, read_concerns):
         combined_write_concerns.update(write_concerns)
 
     combined_read_concerns = dict(collection.read_concern.document.items())
-    
+
     if read_concerns is not None:
         combined_read_concerns.update(read_concerns)
 
     yield collection.with_options(
         write_concern=WriteConcern(**combined_write_concerns),
-        read_concern=ReadConcern(**combined_read_concerns)
+        read_concern=ReadConcern(**combined_read_concerns),
     )

mongoengine/queryset/base.py

@@ -1206,7 +1206,9 @@ class BaseQuerySet:
             raise TypeError("%r is not a valid read concern." % (read_concern,))
 
         queryset = self.clone()
-        queryset._read_concern = ReadConcern(**read_concern) if read_concern is not None else None
+        queryset._read_concern = (
+            ReadConcern(**read_concern) if read_concern is not None else None
+        )
         queryset._cursor_obj = None  # we need to re-create the cursor object whenever we apply read_concern
         return queryset
 

tests/test_context_managers.py

@@ -8,10 +8,10 @@ from mongoengine.context_managers import (
     no_dereference,
     no_sub_classes,
     query_counter,
+    set_read_write_concern,
+    set_write_concern,
     switch_collection,
     switch_db,
-    set_write_concern,
-    set_read_write_concern,
 )
 from mongoengine.pymongo_support import count_documents