[logging] implement warning_advice / TRANSFORMERS_NO_ADVISORY_WARNINGS (#14669)

* [logging] implement warning_advice / TRANSFORMERS_NO_ADVISORY_WARNINGS

* reword

docs/source/main_classes/logging.rst

@@ -1,4 +1,4 @@
-.. 
+..
     Copyright 2020 The HuggingFace Team. All rights reserved.
 
     Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
@@ -32,6 +32,15 @@ to one of the following: ``debug``, ``info``, ``warning``, ``error``, ``critical
 
     TRANSFORMERS_VERBOSITY=error ./myprogram.py
 
+Additionally, some ``warnings`` can be disabled by setting the environment variable
+``TRANSFORMERS_NO_ADVISORY_WARNINGS`` to a true value, like `1`. This will disable any warning that is logged using
+:meth:`logger.warning_advice`. For example:
+
+
+.. code-block:: bash
+
+    TRANSFORMERS_NO_ADVISORY_WARNINGS=1 ./myprogram.py
+
 All the methods of this logging module are documented below, the main ones are
 :func:`transformers.logging.get_verbosity` to get the current level of verbosity in the logger and
 :func:`transformers.logging.set_verbosity` to set the verbosity to the level of your choice. In order (from the least

src/transformers/tokenization_utils_base.py

@@ -1937,7 +1937,7 @@ class PreTrainedTokenizerBase(SpecialTokensMixin, PushToHubMixin):
         # Check all our special tokens are registered as "no split" token (we don't cut them) and are in the vocab
         added_tokens = tokenizer.sanitize_special_tokens()
         if added_tokens:
-            logger.warning(
+            logger.warning_advice(
                 "Special tokens have been added in the vocabulary, make sure the associated word embeddings are fine-tuned or trained."
             )
 

src/transformers/utils/logging.py

@@ -263,3 +263,17 @@ def reset_format() -> None:
 
     for handler in handlers:
         handler.setFormatter(None)
+
+
+def warning_advice(self, *args, **kwargs):
+    """
+    This method is identical to `logger.warning()`, but if env var TRANSFORMERS_NO_ADVISORY_WARNINGS=1 is set, this
+    warning will not be printed
+    """
+    no_advisory_warnings = os.getenv("TRANSFORMERS_NO_ADVISORY_WARNINGS", False)
+    if no_advisory_warnings:
+        return
+    self.warning(*args, **kwargs)
+
+
+logging.Logger.warning_advice = warning_advice

tests/test_logging.py

@@ -17,7 +17,7 @@ import unittest
 
 import transformers.models.bart.tokenization_bart
 from transformers import logging
-from transformers.testing_utils import CaptureLogger, mockenv
+from transformers.testing_utils import CaptureLogger, mockenv, mockenv_context
 
 
 class HfArgumentParserTest(unittest.TestCase):
@@ -103,3 +103,21 @@ class HfArgumentParserTest(unittest.TestCase):
         self.assertIn("Unknown option TRANSFORMERS_VERBOSITY=super-error", cl.out)
 
         # no need to restore as nothing was changed
+
+    def test_advisory_warnings(self):
+        # testing `logger.warning_advice()`
+
+        logger = logging.get_logger("transformers.models.bart.tokenization_bart")
+        msg = "Testing 1, 2, 3"
+
+        with mockenv_context(TRANSFORMERS_NO_ADVISORY_WARNINGS="1"):
+            # nothing should be logged as env var disables this method
+            with CaptureLogger(logger) as cl:
+                logger.warning_advice(msg)
+            self.assertEqual(cl.out, "")
+
+        with mockenv_context(TRANSFORMERS_NO_ADVISORY_WARNINGS=""):
+            # should log normally as TRANSFORMERS_NO_ADVISORY_WARNINGS is unset
+            with CaptureLogger(logger) as cl:
+                logger.warning_advice(msg)
+            self.assertEqual(cl.out, msg + "\n")