def _get_token_from_google_colab()

in src/huggingface_hub/utils/_auth.py [0:0]

• 42 lines of code
• 13 McCabe index (conditional complexity)

def _get_token_from_google_colab() -> Optional[str]:
    """Get token from Google Colab secrets vault using `google.colab.userdata.get(...)`.

    Token is read from the vault only once per session and then stored in a global variable to avoid re-requesting
    access to the vault.
    """
    # If it's not a Google Colab or it's Colab Enterprise, fallback to environment variable or token file authentication
    if not is_google_colab() or is_colab_enterprise():
        return None

    # `google.colab.userdata` is not thread-safe
    # This can lead to a deadlock if multiple threads try to access it at the same time
    # (typically when using `snapshot_download`)
    # => use a lock
    # See https://github.com/huggingface/huggingface_hub/issues/1952 for more details.
    with _GOOGLE_COLAB_SECRET_LOCK:
        global _GOOGLE_COLAB_SECRET
        global _IS_GOOGLE_COLAB_CHECKED

        if _IS_GOOGLE_COLAB_CHECKED:  # request access only once
            return _GOOGLE_COLAB_SECRET

        try:
            from google.colab import userdata  # type: ignore
            from google.colab.errors import Error as ColabError  # type: ignore
        except ImportError:
            return None

        try:
            token = userdata.get("HF_TOKEN")
            _GOOGLE_COLAB_SECRET = _clean_token(token)
        except userdata.NotebookAccessError:
            # Means the user has a secret call `HF_TOKEN` and got a popup "please grand access to HF_TOKEN" and refused it
            # => warn user but ignore error => do not re-request access to user
            warnings.warn(
                "\nAccess to the secret `HF_TOKEN` has not been granted on this notebook."
                "\nYou will not be requested again."
                "\nPlease restart the session if you want to be prompted again."
            )
            _GOOGLE_COLAB_SECRET = None
        except userdata.SecretNotFoundError:
            # Means the user did not define a `HF_TOKEN` secret => warn
            warnings.warn(
                "\nThe secret `HF_TOKEN` does not exist in your Colab secrets."
                "\nTo authenticate with the Hugging Face Hub, create a token in your settings tab "
                "(https://huggingface.co/settings/tokens), set it as secret in your Google Colab and restart your session."
                "\nYou will be able to reuse this secret in all of your notebooks."
                "\nPlease note that authentication is recommended but still optional to access public models or datasets."
            )
            _GOOGLE_COLAB_SECRET = None
        except ColabError as e:
            # Something happen but we don't know what => recommend to open a GitHub issue
            warnings.warn(
                f"\nError while fetching `HF_TOKEN` secret value from your vault: '{str(e)}'."
                "\nYou are not authenticated with the Hugging Face Hub in this notebook."
                "\nIf the error persists, please let us know by opening an issue on GitHub "
                "(https://github.com/huggingface/huggingface_hub/issues/new)."
            )
            _GOOGLE_COLAB_SECRET = None

        _IS_GOOGLE_COLAB_CHECKED = True
        return _GOOGLE_COLAB_SECRET