@pytest.mark.parametrize('model', CLASSES)
def test_list_size(model):
 assert (len(model.COLUMN_WIDTHS) == 3)

@ pytest . mark . parametrize ( 'model' , CLASSES ) def test_list_size ( model ) : assert ( len ( model . COLUMN_WIDTHS ) == 3 )
test if there are 3 items in the column_widths property .