Fix tokenizer load from one file (#19073)

* Fix tokenizer load from one file

* Add a test

* Style
Co-authored-by: Lysandre <lysandre.debut@reseau.eseo.fr>

src/transformers/tokenization_utils_base.py

@@ -1726,6 +1726,8 @@ class PreTrainedTokenizerBase(SpecialTokensMixin, PushToHubMixin):
         for file_id, file_path in vocab_files.items():
             if file_path is None:
                 resolved_vocab_files[file_id] = None
+            elif os.path.isfile(file_path):
+                resolved_vocab_files[file_id] = file_path
             elif is_remote_url(file_path):
                 resolved_vocab_files[file_id] = download_url(file_path, proxies=proxies)
             else:

tests/test_tokenization_common.py

@@ -31,6 +31,7 @@ from pathlib import Path
 from typing import TYPE_CHECKING, Any, Dict, List, Tuple, Union
 
 from huggingface_hub import HfFolder, delete_repo, set_access_token
+from huggingface_hub.file_download import http_get
 from parameterized import parameterized
 from requests.exceptions import HTTPError
 from transformers import (
@@ -3889,6 +3890,16 @@ class TokenizerUtilTester(unittest.TestCase):
             # This check we did call the fake head request
             mock_head.assert_called()
 
+    def test_legacy_load_from_one_file(self):
+        try:
+            tmp_file = tempfile.mktemp()
+            with open(tmp_file, "wb") as f:
+                http_get("https://huggingface.co/albert-base-v1/resolve/main/spiece.model", f)
+
+            AlbertTokenizer.from_pretrained(tmp_file)
+        finally:
+            os.remove(tmp_file)
+
 
 @is_staging_test
 class TokenizerPushToHubTester(unittest.TestCase):