def is_hdf5_file(fp):
    """Guess if file is HDF5.

    Parameters
    ----------
    fn : str
        File name

    Returns
    -------
    bool
        Whether the file is an HDF5 file
    """
    with open(fp, 'rb') as f:
        return f.read(8) == b'\x89HDF\r\n\x1a\n'
