client.py 文件源码

def _get_application_default_credential_from_file(filename):
    """Build the Application Default Credentials from file."""
    # read the credentials from the file
    with open(filename) as file_obj:
        client_credentials = json.load(file_obj)

    credentials_type = client_credentials.get('type')
    if credentials_type == AUTHORIZED_USER:
        required_fields = set(['client_id', 'client_secret', 'refresh_token'])
    elif credentials_type == SERVICE_ACCOUNT:
        required_fields = set(['client_id', 'client_email', 'private_key_id',
                               'private_key'])
    else:
        raise ApplicationDefaultCredentialsError(
            "'type' field should be defined (and have one of the '" +
            AUTHORIZED_USER + "' or '" + SERVICE_ACCOUNT + "' values)")

    missing_fields = required_fields.difference(client_credentials.keys())

    if missing_fields:
        _raise_exception_for_missing_fields(missing_fields)

    if client_credentials['type'] == AUTHORIZED_USER:
        return GoogleCredentials(
            access_token=None,
            client_id=client_credentials['client_id'],
            client_secret=client_credentials['client_secret'],
            refresh_token=client_credentials['refresh_token'],
            token_expiry=None,
            token_uri=GOOGLE_TOKEN_URI,
            user_agent='Python client library')
    else:  # client_credentials['type'] == SERVICE_ACCOUNT
        from oauth2client.service_account import ServiceAccountCredentials
        return ServiceAccountCredentials.from_json_keyfile_dict(
            client_credentials)