client.py 文件源码

def from_stream(credential_filename):
        """Create a Credentials object by reading information from a file.

        It returns an object of type GoogleCredentials.

        Args:
            credential_filename: the path to the file from where the
                                 credentials are to be read

        Raises:
            ApplicationDefaultCredentialsError: raised when the credentials
                                                fail to be retrieved.
        """
        if credential_filename and os.path.isfile(credential_filename):
            try:
                return _get_application_default_credential_from_file(
                    credential_filename)
            except (ApplicationDefaultCredentialsError, ValueError) as error:
                extra_help = (' (provided as parameter to the '
                              'from_stream() method)')
                _raise_exception_for_reading_json(credential_filename,
                                                  extra_help,
                                                  error)
        else:
            raise ApplicationDefaultCredentialsError(
                'The parameter passed to the from_stream() '
                'method should point to a file.')