def many_columns_non_petastorm_dataset(request, tmpdir_factory):
    """This dataset has 1000 columns. All of the same int32 type."""

    def _dataset_no_cache():
        path = tmpdir_factory.mktemp("data").strpath
        url = 'file://' + path
        data = create_many_columns_non_petastorm_dataset(url, 10)
        dataset = SyntheticDataset(url=url, path=path, data=data)
        return dataset

    return maybe_cached_dataset(request.config, 'many_column_non_petastorm', _dataset_no_cache)
This dataset has 1000 columns. All of the same int32 type.
petastorm/tests/conftest.py