Fix tqdm logging into multiple files with allennlp-optuna (#5235)

* Fix tqdm logging into multiple files with allennlp-optuna

* Update changelog

* Add unittest for resetting tqdm logger handlers

Co-authored-by: Pete <petew@allenai.org>

CHANGELOG.md

@@ -52,6 +52,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fixed the potential for a race condition with `cached_path()` when extracting archives. Although the race condition
   is still possible if used with `force_extract=True`.
 - Fixed `wandb` callback to work in distributed training.
+- Fixed `tqdm` logging into multiple files with `allennlp-optuna`.
 
 
 ## [v2.4.0](https://github.com/allenai/allennlp/releases/tag/v2.4.0) - 2021-04-22

allennlp/common/logging.py

@@ -126,4 +126,5 @@ def excepthook(exctype, value, traceback):
     # also log tqdm
     from allennlp.common.tqdm import logger as tqdm_logger
 
+    tqdm_logger.handlers.clear()
     tqdm_logger.addHandler(file_handler)

tests/common/logging_test.py

@@ -2,8 +2,9 @@
 import logging
 import random
 
-from allennlp.common.logging import AllenNlpLogger
+from allennlp.common.logging import AllenNlpLogger, prepare_global_logging
 from allennlp.common.testing import AllenNlpTestCase
+from allennlp.common.tqdm import Tqdm
 
 
 class TestLogging(AllenNlpTestCase):
@@ -64,3 +65,18 @@ def test_getLogger(self):
         logger = logging.getLogger("test_logger")
 
         assert isinstance(logger, AllenNlpLogger)
+
+    def test_reset_tqdm_logger_handlers(self):
+        serialization_dir_a = os.path.join(self.TEST_DIR, "test_a")
+        os.makedirs(serialization_dir_a, exist_ok=True)
+        prepare_global_logging(serialization_dir_a)
+        serialization_dir_b = os.path.join(self.TEST_DIR, "test_b")
+        os.makedirs(serialization_dir_b, exist_ok=True)
+        prepare_global_logging(serialization_dir_b)
+        # Use range(1) to make sure there should be only 2 lines in the file (0% and 100%)
+        for _ in Tqdm.tqdm(range(1)):
+            pass
+        with open(os.path.join(serialization_dir_a, "out.log"), "r") as f:
+            assert len(f.readlines()) == 0
+        with open(os.path.join(serialization_dir_b, "out.log"), "r") as f:
+            assert len(f.readlines()) == 2