removed prints and improved changelog

Author: bagerard

docs/changelog.rst

@@ -8,6 +8,10 @@ Development
 ===========
 - (Fill this out as you fix issues and develop your features).
 - Add support for transaction through run_in_transaction (kudos to juannyG for this) #2569
+  Some considerations:
+    - make sure to read https://www.mongodb.com/docs/manual/core/transactions-in-applications/#callback-api-vs-core-api
+    - run_in_transaction context manager relies on Pymongo coreAPI, it will retry automatically in case of `UnknownTransactionCommitResult` but not `TransientTransactionError` exceptions
+    - Using .count() in a transaction will always use Collection.count_document (as estimated_document_count is not supported in transactions)
 
 Changes in 0.29.0
 =================

mongoengine/context_managers.py

@@ -1,4 +1,5 @@
 import contextlib
+import logging
 import threading
 from contextlib import contextmanager
 
@@ -327,15 +328,16 @@ def _commit_with_retry(session):
         try:
             # Commit uses write concern set at transaction start.
             session.commit_transaction()
-            print("Transaction committed.")
             break
         except (ConnectionFailure, OperationFailure) as exc:
             # Can retry commit
             if exc.has_error_label("UnknownTransactionCommitResult"):
-                print("UnknownTransactionCommitResult, retrying commit operation ...")
+                logging.warning(
+                    "UnknownTransactionCommitResult, retrying commit operation ..."
+                )
                 continue
             else:
-                print("Error during commit ...")
+                # Error during commit
                 raise