'Opening zipped files in a writeable mode should fail.'

def test_open_zipped_writeable(self):

    zf = self._make_zip_file()
    pytest.raises(IOError, fits.open, zf, 'update')
    pytest.raises(IOError, fits.open, zf, 'append')
    zf = zipfile.ZipFile(zf, 'a')
    pytest.raises(IOError, fits.open, zf, 'update')
    pytest.raises(IOError, fits.open, zf, 'append')
