Function test_write_dataset_parquet

python/pyarrow/tests/test_dataset.py:4917–4957

(tempdir)

@pytest.mark.numpy
@pytest.mark.parquet
def test_write_dataset_parquet(tempdir):
    table = pa.table([
        pa.array(range(20), type="uint32"),
        pa.array(np.arange("2012-01-01", 20, dtype="datetime64[D]").astype(
            "datetime64[ns]")),
        pa.array(np.repeat(['a', 'b'], 10))
    ], names=["f1", "f2", "part"])

    # using default "parquet" format string

    base_dir = tempdir / 'parquet_dataset'
    ds.write_dataset(table, base_dir, format="parquet")
    # check that all files are present
    file_paths = list(base_dir.rglob("*"))
    expected_paths = [base_dir / "part-0.parquet"]
    assert set(file_paths) == set(expected_paths)
    # check Table roundtrip with default version
    result = ds.dataset(base_dir, format="parquet").to_table()
    assert result.equals(table)

    # using custom options
    for version in ["1.0", "2.4", "2.6"]:
        format = ds.ParquetFileFormat()
        opts = format.make_write_options(version=version)
        assert "<pyarrow.dataset.ParquetFileWriteOptions" in repr(opts)
        base_dir = tempdir / f'parquet_dataset_version{version}'
        ds.write_dataset(table, base_dir, format=format, file_options=opts)
        meta = pq.read_metadata(base_dir / "part-0.parquet")
        expected_version = "1.0" if version == "1.0" else "2.6"
        assert meta.format_version == expected_version

        # ensure version is actually honored based on supported datatypes
        result = ds.dataset(base_dir, format="parquet").to_table()
        schema = table.schema
        if version == "1.0":
            # uint32 is written as int64
            schema = schema.set(0, schema.field(0).with_type(pa.int64()))
        if version in ("1.0", "2.4"):
            schema = schema.set(1, schema.field(1).with_type(pa.timestamp("us")))
        expected = table.cast(schema)
        assert result.equals(expected)


def test_write_dataset_csv(tempdir):