AutoTokenizer.from_pretrained fails to load locally saved pretrained tokenizer (PyTorch)

Question

I am new to PyTorch and recently, I have been trying to work with Transformers. I am using pretrained tokenizers provided by HuggingFace.
I am successful in downloading and running them. But if I try to save them and load again, then some error occurs.
If I use AutoTokenizer.from_pretrained to download a tokenizer, then it works.

[1]:    tokenizer = AutoTokenizer.from_pretrained('distilroberta-base')
        text = "Hello there"
        enc = tokenizer.encode_plus(text)
        enc.keys()

Out[1]: dict_keys(['input_ids', 'attention_mask'])

But if I save it using tokenizer.save_pretrained("distilroberta-tokenizer") and try to load it locally, then it fails.

[2]:    tmp = AutoTokenizer.from_pretrained('distilroberta-tokenizer')


---------------------------------------------------------------------------
OSError                                   Traceback (most recent call last)
/opt/conda/lib/python3.7/site-packages/transformers/configuration_utils.py in get_config_dict(cls, pretrained_model_name_or_path, **kwargs)
    238                 resume_download=resume_download,
--> 239                 local_files_only=local_files_only,
    240             )

/opt/conda/lib/python3.7/site-packages/transformers/file_utils.py in cached_path(url_or_filename, cache_dir, force_download, proxies, resume_download, user_agent, extract_compressed_file, force_extract, local_files_only)
    266         # File, but it doesn't exist.
--> 267         raise EnvironmentError("file {} not found".format(url_or_filename))
    268     else:

OSError: file distilroberta-tokenizer/config.json not found

During handling of the above exception, another exception occurred:

OSError                                   Traceback (most recent call last)
<ipython-input-25-3bd2f7a79271> in <module>
----> 1 tmp = AutoTokenizer.from_pretrained("distilroberta-tokenizer")

/opt/conda/lib/python3.7/site-packages/transformers/tokenization_auto.py in from_pretrained(cls, pretrained_model_name_or_path, *inputs, **kwargs)
    193         config = kwargs.pop("config", None)
    194         if not isinstance(config, PretrainedConfig):
--> 195             config = AutoConfig.from_pretrained(pretrained_model_name_or_path, **kwargs)
    196 
    197         if "bert-base-japanese" in pretrained_model_name_or_path:

/opt/conda/lib/python3.7/site-packages/transformers/configuration_auto.py in from_pretrained(cls, pretrained_model_name_or_path, **kwargs)
    194 
    195         """
--> 196         config_dict, _ = PretrainedConfig.get_config_dict(pretrained_model_name_or_path, **kwargs)
    197 
    198         if "model_type" in config_dict:

/opt/conda/lib/python3.7/site-packages/transformers/configuration_utils.py in get_config_dict(cls, pretrained_model_name_or_path, **kwargs)
    250                 f"- or '{pretrained_model_name_or_path}' is the correct path to a directory containing a {CONFIG_NAME} file\n\n"
    251             )
--> 252             raise EnvironmentError(msg)
    253 
    254         except json.JSONDecodeError:

OSError: Can't load config for 'distilroberta-tokenizer'. Make sure that:

- 'distilroberta-tokenizer' is a correct model identifier listed on 'https://huggingface.co/models'

- or 'distilroberta-tokenizer' is the correct path to a directory containing a config.json file

Its saying 'config.josn' is missing form the directory. On checking the directory, I am getting list of these files:

[3]:    !ls distilroberta-tokenizer

Out[3]: merges.txt  special_tokens_map.json  tokenizer_config.json  vocab.json

I know this problem has been posted earlier but none of them seems to work. I have also tried to follow the docs but still can't make it work.
Any help would be appreciated.

Answer 1

I see several issues in your code which I listed below:

1. distilroberta-tokenizer is a directory containing the vocab config, etc files. Please make sure to create this dir first.

2. Using AutoTokenizer works if this dir contains config.json and NOT tokenizer_config.json. So, please rename this file.

I modified your code below and it works.

dir_name = "distilroberta-tokenizer"

if os.path.isdir(dir_name) == False:
    os.mkdir(dir_name)  

tokenizer.save_pretrained(dir_name)

#Rename config file now

#tmp = AutoTokenizer.from_pretrained(dir_name)   

I hope this helps!

Thanks!