def get_dir_from_zipfile(zip_file, fallback=None):
    """Return the name of the root folder in a zip file.

    :param zip_file: a :class:`zipfile.ZipFile` instance.
    :param fallback: if `None`, the name of the zip file is used. This is
        returned if the zip file contains more than one top-level directory,
        or none at all.
    """
    fallback = fallback or zip_file.filename
    directories = [name for name in zip_file.namelist() if name.endswith("/")
                   and len(PurePath(name).parts) == 1]
    return fallback if len(directories) > 1 else directories[0]
def _model_ready_for_local_init(self, sess):
    """Checks if the model is ready to run local_init_op.

    Args:
      sess: A `Session`.

    Returns:
      A tuple (is_ready, msg), where is_ready is True if ready to run
      local_init_op and False otherwise, and msg is `None` if the model is
      ready to run local_init_op, a `String` with the reason why it is not ready
      otherwise.
    """
    return _ready(self._ready_for_local_init_op, sess,
                  "Model not ready for local init")