venv/lib/python3.10/site-packages/pyarrow/tests/parquet/test_pandas.py

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# to you under the Apache License, Version 2.0 (the
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# with the License.  You may obtain a copy of the License at
#
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# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.

import io
import json

import numpy as np
import pytest

import pyarrow as pa
from pyarrow.fs import LocalFileSystem, SubTreeFileSystem
from pyarrow.util import guid
from pyarrow.vendored.version import Version

try:
    import pyarrow.parquet as pq
    from pyarrow.tests.parquet.common import (_read_table, _test_dataframe,
                                              _write_table)
except ImportError:
    pq = None


try:
    import pandas as pd
    import pandas.testing as tm

    from pyarrow.tests.parquet.common import (_roundtrip_pandas_dataframe,
                                              alltypes_sample)
except ImportError:
    pd = tm = None


# Marks all of the tests in this module
# Ignore these with pytest ... -m 'not parquet'
pytestmark = pytest.mark.parquet


@pytest.mark.pandas
def test_pandas_parquet_custom_metadata(tempdir):
    df = alltypes_sample(size=10000)

    filename = tempdir / 'pandas_roundtrip.parquet'
    arrow_table = pa.Table.from_pandas(df)
    assert b'pandas' in arrow_table.schema.metadata

    _write_table(arrow_table, filename)

    metadata = pq.read_metadata(filename).metadata
    assert b'pandas' in metadata

    js = json.loads(metadata[b'pandas'].decode('utf8'))
    assert js['index_columns'] == [{'kind': 'range',
                                    'name': None,
                                    'start': 0, 'stop': 10000,
                                    'step': 1}]


@pytest.mark.pandas
def test_merging_parquet_tables_with_different_pandas_metadata(tempdir):
    # ARROW-3728: Merging Parquet Files - Pandas Meta in Schema Mismatch
    schema = pa.schema([
        pa.field('int', pa.int16()),
        pa.field('float', pa.float32()),
        pa.field('string', pa.string())
    ])
    df1 = pd.DataFrame({
        'int': np.arange(3, dtype=np.uint8),
        'float': np.arange(3, dtype=np.float32),
        'string': ['ABBA', 'EDDA', 'ACDC']
    })
    df2 = pd.DataFrame({
        'int': [4, 5],
        'float': [1.1, None],
        'string': [None, None]
    })
    table1 = pa.Table.from_pandas(df1, schema=schema, preserve_index=False)
    table2 = pa.Table.from_pandas(df2, schema=schema, preserve_index=False)

    assert not table1.schema.equals(table2.schema, check_metadata=True)
    assert table1.schema.equals(table2.schema)

    writer = pq.ParquetWriter(tempdir / 'merged.parquet', schema=schema)
    writer.write_table(table1)
    writer.write_table(table2)


@pytest.mark.pandas
def test_pandas_parquet_column_multiindex(tempdir):
    df = alltypes_sample(size=10)
    df.columns = pd.MultiIndex.from_tuples(
        list(zip(df.columns, df.columns[::-1])),
        names=['level_1', 'level_2']
    )

    filename = tempdir / 'pandas_roundtrip.parquet'
    arrow_table = pa.Table.from_pandas(df)
    assert arrow_table.schema.pandas_metadata is not None

    _write_table(arrow_table, filename)

    table_read = pq.read_pandas(filename)
    df_read = table_read.to_pandas()
    tm.assert_frame_equal(df, df_read)


@pytest.mark.pandas
def test_pandas_parquet_2_0_roundtrip_read_pandas_no_index_written(tempdir):
    df = alltypes_sample(size=10000)

    filename = tempdir / 'pandas_roundtrip.parquet'
    arrow_table = pa.Table.from_pandas(df, preserve_index=False)
    js = arrow_table.schema.pandas_metadata
    assert not js['index_columns']
    # ARROW-2170
    # While index_columns should be empty, columns needs to be filled still.
    assert js['columns']

    _write_table(arrow_table, filename)
    table_read = pq.read_pandas(filename)

    js = table_read.schema.pandas_metadata
    assert not js['index_columns']

    read_metadata = table_read.schema.metadata
    assert arrow_table.schema.metadata == read_metadata

    df_read = table_read.to_pandas()
    tm.assert_frame_equal(df, df_read)


@pytest.mark.pandas
def test_pandas_parquet_native_file_roundtrip():
    df = _test_dataframe(10000)
    arrow_table = pa.Table.from_pandas(df)
    imos = pa.BufferOutputStream()
    _write_table(arrow_table, imos, version='2.6')
    buf = imos.getvalue()
    reader = pa.BufferReader(buf)
    df_read = _read_table(reader).to_pandas()
    tm.assert_frame_equal(df, df_read)


@pytest.mark.pandas
def test_read_pandas_column_subset():
    df = _test_dataframe(10000)
    arrow_table = pa.Table.from_pandas(df)
    imos = pa.BufferOutputStream()
    _write_table(arrow_table, imos, version='2.6')
    buf = imos.getvalue()
    reader = pa.BufferReader(buf)
    df_read = pq.read_pandas(
        reader, columns=['strings', 'uint8'],
    ).to_pandas()
    tm.assert_frame_equal(df[['strings', 'uint8']], df_read)


@pytest.mark.pandas
def test_pandas_parquet_empty_roundtrip():
    df = _test_dataframe(0)
    arrow_table = pa.Table.from_pandas(df)
    imos = pa.BufferOutputStream()
    _write_table(arrow_table, imos, version='2.6')
    buf = imos.getvalue()
    reader = pa.BufferReader(buf)
    df_read = _read_table(reader).to_pandas()
    tm.assert_frame_equal(df, df_read)


@pytest.mark.pandas
def test_pandas_can_write_nested_data():
    data = {
        "agg_col": [
            {"page_type": 1},
            {"record_type": 1},
            {"non_consecutive_home": 0},
        ],
        "uid_first": "1001"
    }
    df = pd.DataFrame(data=data)
    arrow_table = pa.Table.from_pandas(df)
    imos = pa.BufferOutputStream()
    # This succeeds under V2
    _write_table(arrow_table, imos)


@pytest.mark.pandas
def test_pandas_parquet_pyfile_roundtrip(tempdir):
    filename = tempdir / 'pandas_pyfile_roundtrip.parquet'
    size = 5
    df = pd.DataFrame({
        'int64': np.arange(size, dtype=np.int64),
        'float32': np.arange(size, dtype=np.float32),
        'float64': np.arange(size, dtype=np.float64),
        'bool': np.random.randn(size) > 0,
        'strings': ['foo', 'bar', None, 'baz', 'qux']
    })

    arrow_table = pa.Table.from_pandas(df)

    with filename.open('wb') as f:
        _write_table(arrow_table, f, version="2.6")

    data = io.BytesIO(filename.read_bytes())

    table_read = _read_table(data)
    df_read = table_read.to_pandas()
    tm.assert_frame_equal(df, df_read)


@pytest.mark.pandas
def test_pandas_parquet_configuration_options(tempdir):
    size = 10000
    np.random.seed(0)
    df = pd.DataFrame({
        'uint8': np.arange(size, dtype=np.uint8),
        'uint16': np.arange(size, dtype=np.uint16),
        'uint32': np.arange(size, dtype=np.uint32),
        'uint64': np.arange(size, dtype=np.uint64),
        'int8': np.arange(size, dtype=np.int16),
        'int16': np.arange(size, dtype=np.int16),
        'int32': np.arange(size, dtype=np.int32),
        'int64': np.arange(size, dtype=np.int64),
        'float32': np.arange(size, dtype=np.float32),
        'float64': np.arange(size, dtype=np.float64),
        'bool': np.random.randn(size) > 0
    })
    filename = tempdir / 'pandas_roundtrip.parquet'
    arrow_table = pa.Table.from_pandas(df)

    for use_dictionary in [True, False]:
        _write_table(arrow_table, filename, version='2.6',
                     use_dictionary=use_dictionary)
        table_read = _read_table(filename)
        df_read = table_read.to_pandas()
        tm.assert_frame_equal(df, df_read)

    for write_statistics in [True, False]:
        _write_table(arrow_table, filename, version='2.6',
                     write_statistics=write_statistics)
        table_read = _read_table(filename)
        df_read = table_read.to_pandas()
        tm.assert_frame_equal(df, df_read)

    for compression in ['NONE', 'SNAPPY', 'GZIP', 'LZ4', 'ZSTD']:
        if (compression != 'NONE' and
                not pa.lib.Codec.is_available(compression)):
            continue
        _write_table(arrow_table, filename, version='2.6',
                     compression=compression)
        table_read = _read_table(filename)
        df_read = table_read.to_pandas()
        tm.assert_frame_equal(df, df_read)


@pytest.mark.pandas
@pytest.mark.filterwarnings("ignore:Parquet format '2.0':FutureWarning")
def test_spark_flavor_preserves_pandas_metadata():
    df = _test_dataframe(size=100)
    df.index = np.arange(0, 10 * len(df), 10)
    df.index.name = 'foo'

    result = _roundtrip_pandas_dataframe(df, {'version': '2.0',
                                              'flavor': 'spark'})
    tm.assert_frame_equal(result, df)


@pytest.mark.pandas
def test_index_column_name_duplicate(tempdir):
    data = {
        'close': {
            pd.Timestamp('2017-06-30 01:31:00'): 154.99958999999998,
            pd.Timestamp('2017-06-30 01:32:00'): 154.99958999999998,
        },
        'time': {
            pd.Timestamp('2017-06-30 01:31:00'): pd.Timestamp(
                '2017-06-30 01:31:00'
            ),
            pd.Timestamp('2017-06-30 01:32:00'): pd.Timestamp(
                '2017-06-30 01:32:00'
            ),
        }
    }
    path = str(tempdir / 'data.parquet')

    # Pandas v2 defaults to [ns], but Arrow defaults to [us] time units
    # so we need to cast the pandas dtype. Pandas v1 will always silently
    # coerce to [ns] due to lack of non-[ns] support.
    dfx = pd.DataFrame(data, dtype='datetime64[us]').set_index('time', drop=False)

    tdfx = pa.Table.from_pandas(dfx)
    _write_table(tdfx, path)
    arrow_table = _read_table(path)
    result_df = arrow_table.to_pandas()
    tm.assert_frame_equal(result_df, dfx)


@pytest.mark.pandas
def test_multiindex_duplicate_values(tempdir):
    num_rows = 3
    numbers = list(range(num_rows))
    index = pd.MultiIndex.from_arrays(
        [['foo', 'foo', 'bar'], numbers],
        names=['foobar', 'some_numbers'],
    )

    df = pd.DataFrame({'numbers': numbers}, index=index)
    table = pa.Table.from_pandas(df)

    filename = tempdir / 'dup_multi_index_levels.parquet'

    _write_table(table, filename)
    result_table = _read_table(filename)
    assert table.equals(result_table)

    result_df = result_table.to_pandas()
    tm.assert_frame_equal(result_df, df)


@pytest.mark.pandas
def test_backwards_compatible_index_naming(datadir):
    expected_string = b"""\
carat        cut  color  clarity  depth  table  price     x     y     z
 0.23      Ideal      E      SI2   61.5   55.0    326  3.95  3.98  2.43
 0.21    Premium      E      SI1   59.8   61.0    326  3.89  3.84  2.31
 0.23       Good      E      VS1   56.9   65.0    327  4.05  4.07  2.31
 0.29    Premium      I      VS2   62.4   58.0    334  4.20  4.23  2.63
 0.31       Good      J      SI2   63.3   58.0    335  4.34  4.35  2.75
 0.24  Very Good      J     VVS2   62.8   57.0    336  3.94  3.96  2.48
 0.24  Very Good      I     VVS1   62.3   57.0    336  3.95  3.98  2.47
 0.26  Very Good      H      SI1   61.9   55.0    337  4.07  4.11  2.53
 0.22       Fair      E      VS2   65.1   61.0    337  3.87  3.78  2.49
 0.23  Very Good      H      VS1   59.4   61.0    338  4.00  4.05  2.39"""
    expected = pd.read_csv(io.BytesIO(expected_string), sep=r'\s{2,}',
                           index_col=None, header=0, engine='python')
    table = _read_table(datadir / 'v0.7.1.parquet')
    result = table.to_pandas()
    tm.assert_frame_equal(result, expected)


@pytest.mark.pandas
def test_backwards_compatible_index_multi_level_named(datadir):
    expected_string = b"""\
carat        cut  color  clarity  depth  table  price     x     y     z
 0.23      Ideal      E      SI2   61.5   55.0    326  3.95  3.98  2.43
 0.21    Premium      E      SI1   59.8   61.0    326  3.89  3.84  2.31
 0.23       Good      E      VS1   56.9   65.0    327  4.05  4.07  2.31
 0.29    Premium      I      VS2   62.4   58.0    334  4.20  4.23  2.63
 0.31       Good      J      SI2   63.3   58.0    335  4.34  4.35  2.75
 0.24  Very Good      J     VVS2   62.8   57.0    336  3.94  3.96  2.48
 0.24  Very Good      I     VVS1   62.3   57.0    336  3.95  3.98  2.47
 0.26  Very Good      H      SI1   61.9   55.0    337  4.07  4.11  2.53
 0.22       Fair      E      VS2   65.1   61.0    337  3.87  3.78  2.49
 0.23  Very Good      H      VS1   59.4   61.0    338  4.00  4.05  2.39"""
    expected = pd.read_csv(
        io.BytesIO(expected_string), sep=r'\s{2,}',
        index_col=['cut', 'color', 'clarity'],
        header=0, engine='python'
    ).sort_index()

    table = _read_table(datadir / 'v0.7.1.all-named-index.parquet')
    result = table.to_pandas()
    tm.assert_frame_equal(result, expected)


@pytest.mark.pandas
def test_backwards_compatible_index_multi_level_some_named(datadir):
    expected_string = b"""\
carat        cut  color  clarity  depth  table  price     x     y     z
 0.23      Ideal      E      SI2   61.5   55.0    326  3.95  3.98  2.43
 0.21    Premium      E      SI1   59.8   61.0    326  3.89  3.84  2.31
 0.23       Good      E      VS1   56.9   65.0    327  4.05  4.07  2.31
 0.29    Premium      I      VS2   62.4   58.0    334  4.20  4.23  2.63
 0.31       Good      J      SI2   63.3   58.0    335  4.34  4.35  2.75
 0.24  Very Good      J     VVS2   62.8   57.0    336  3.94  3.96  2.48
 0.24  Very Good      I     VVS1   62.3   57.0    336  3.95  3.98  2.47
 0.26  Very Good      H      SI1   61.9   55.0    337  4.07  4.11  2.53
 0.22       Fair      E      VS2   65.1   61.0    337  3.87  3.78  2.49
 0.23  Very Good      H      VS1   59.4   61.0    338  4.00  4.05  2.39"""
    expected = pd.read_csv(
        io.BytesIO(expected_string),
        sep=r'\s{2,}', index_col=['cut', 'color', 'clarity'],
        header=0, engine='python'
    ).sort_index()
    expected.index = expected.index.set_names(['cut', None, 'clarity'])

    table = _read_table(datadir / 'v0.7.1.some-named-index.parquet')
    result = table.to_pandas()
    tm.assert_frame_equal(result, expected)


@pytest.mark.pandas
def test_backwards_compatible_column_metadata_handling(datadir):
    if Version("2.2.0") <= Version(pd.__version__):
        # TODO: regression in pandas
        # https://github.com/pandas-dev/pandas/issues/56775
        pytest.skip("Regression in pandas 2.2.0")
    expected = pd.DataFrame(
        {'a': [1, 2, 3], 'b': [.1, .2, .3],
         'c': pd.date_range("2017-01-01", periods=3, tz='Europe/Brussels')})
    expected.index = pd.MultiIndex.from_arrays(
        [['a', 'b', 'c'],
         pd.date_range("2017-01-01", periods=3, tz='Europe/Brussels')],
        names=['index', None])

    path = datadir / 'v0.7.1.column-metadata-handling.parquet'
    table = _read_table(path)
    result = table.to_pandas()
    tm.assert_frame_equal(result, expected)

    table = _read_table(
        path, columns=['a'])
    result = table.to_pandas()
    tm.assert_frame_equal(result, expected[['a']].reset_index(drop=True))


@pytest.mark.pandas
def test_categorical_index_survives_roundtrip():
    # ARROW-3652, addressed by ARROW-3246
    df = pd.DataFrame([['a', 'b'], ['c', 'd']], columns=['c1', 'c2'])
    df['c1'] = df['c1'].astype('category')
    df = df.set_index(['c1'])

    table = pa.Table.from_pandas(df)
    bos = pa.BufferOutputStream()
    pq.write_table(table, bos)
    ref_df = pq.read_pandas(bos.getvalue()).to_pandas()
    assert isinstance(ref_df.index, pd.CategoricalIndex)
    assert ref_df.index.equals(df.index)


@pytest.mark.pandas
def test_categorical_order_survives_roundtrip():
    # ARROW-6302
    df = pd.DataFrame({"a": pd.Categorical(
        ["a", "b", "c", "a"], categories=["b", "c", "d"], ordered=True)})

    table = pa.Table.from_pandas(df)
    bos = pa.BufferOutputStream()
    pq.write_table(table, bos)

    contents = bos.getvalue()
    result = pq.read_pandas(contents).to_pandas()

    tm.assert_frame_equal(result, df)


@pytest.mark.pandas
def test_pandas_categorical_na_type_row_groups():
    # ARROW-5085
    df = pd.DataFrame({"col": [None] * 100, "int": [1.0] * 100})
    df_category = df.astype({"col": "category", "int": "category"})
    table = pa.Table.from_pandas(df)
    table_cat = pa.Table.from_pandas(df_category)
    buf = pa.BufferOutputStream()

    # it works
    pq.write_table(table_cat, buf, version='2.6', chunk_size=10)
    result = pq.read_table(buf.getvalue())

    # Result is non-categorical
    assert result[0].equals(table[0])
    assert result[1].equals(table[1])


@pytest.mark.pandas
def test_pandas_categorical_roundtrip():
    # ARROW-5480, this was enabled by ARROW-3246

    # Have one of the categories unobserved and include a null (-1)
    codes = np.array([2, 0, 0, 2, 0, -1, 2], dtype='int32')
    categories = ['foo', 'bar', 'baz']
    df = pd.DataFrame({'x': pd.Categorical.from_codes(
        codes, categories=categories)})

    buf = pa.BufferOutputStream()
    pq.write_table(pa.table(df), buf)

    result = pq.read_table(buf.getvalue()).to_pandas()
    assert result.x.dtype == 'category'
    assert (result.x.cat.categories == categories).all()
    tm.assert_frame_equal(result, df)


@pytest.mark.pandas
def test_categories_with_string_pyarrow_dtype(tempdir):
    # gh-33727: writing to parquet should not fail
    if Version(pd.__version__) < Version("1.3.0"):
        pytest.skip("PyArrow backed string data type introduced in pandas 1.3.0")

    df1 = pd.DataFrame({"x": ["foo", "bar", "foo"]}, dtype="string[pyarrow]")
    df1 = df1.astype("category")

    df2 = pd.DataFrame({"x": ["foo", "bar", "foo"]})
    df2 = df2.astype("category")

    # categories should be converted to pa.Array
    assert pa.array(df1["x"]).to_pylist() == pa.array(df2["x"]).to_pylist()
    assert pa.array(df1["x"].cat.categories.values).to_pylist() == pa.array(
        df2["x"].cat.categories.values).to_pylist()

    path = str(tempdir / 'cat.parquet')
    pq.write_table(pa.table(df1), path)
    result = pq.read_table(path).to_pandas()

    tm.assert_frame_equal(result, df2)


@pytest.mark.pandas
def test_write_to_dataset_pandas_preserve_extensiondtypes(tempdir):
    df = pd.DataFrame({'part': 'a', "col": [1, 2, 3]})
    df['col'] = df['col'].astype("Int64")
    table = pa.table(df)

    pq.write_to_dataset(
        table, str(tempdir / "case1"), partition_cols=['part'],
    )
    result = pq.read_table(str(tempdir / "case1")).to_pandas()
    tm.assert_frame_equal(result[["col"]], df[["col"]])

    pq.write_to_dataset(table, str(tempdir / "case2"))
    result = pq.read_table(str(tempdir / "case2")).to_pandas()
    tm.assert_frame_equal(result[["col"]], df[["col"]])

    pq.write_table(table, str(tempdir / "data.parquet"))
    result = pq.read_table(str(tempdir / "data.parquet")).to_pandas()
    tm.assert_frame_equal(result[["col"]], df[["col"]])


@pytest.mark.pandas
def test_write_to_dataset_pandas_preserve_index(tempdir):
    # ARROW-8251 - preserve pandas index in roundtrip

    df = pd.DataFrame({'part': ['a', 'a', 'b'], "col": [1, 2, 3]})
    df.index = pd.Index(['a', 'b', 'c'], name="idx")
    table = pa.table(df)
    df_cat = df[["col", "part"]].copy()
    df_cat["part"] = df_cat["part"].astype("category")

    pq.write_to_dataset(
        table, str(tempdir / "case1"), partition_cols=['part'],
    )
    result = pq.read_table(str(tempdir / "case1")).to_pandas()
    tm.assert_frame_equal(result, df_cat)

    pq.write_to_dataset(table, str(tempdir / "case2"))
    result = pq.read_table(str(tempdir / "case2")).to_pandas()
    tm.assert_frame_equal(result, df)

    pq.write_table(table, str(tempdir / "data.parquet"))
    result = pq.read_table(str(tempdir / "data.parquet")).to_pandas()
    tm.assert_frame_equal(result, df)


@pytest.mark.pandas
@pytest.mark.parametrize('preserve_index', [True, False, None])
@pytest.mark.parametrize('metadata_fname', ["_metadata", "_common_metadata"])
def test_dataset_read_pandas_common_metadata(
    tempdir, preserve_index, metadata_fname
):
    # ARROW-1103
    nfiles = 5
    size = 5

    dirpath = tempdir / guid()
    dirpath.mkdir()

    test_data = []
    frames = []
    paths = []
    for i in range(nfiles):
        df = _test_dataframe(size, seed=i)
        df.index = pd.Index(
            np.arange(i * size, (i + 1) * size, dtype="int64"), name='index'
        )

        path = dirpath / '{}.parquet'.format(i)

        table = pa.Table.from_pandas(df, preserve_index=preserve_index)

        # Obliterate metadata
        table = table.replace_schema_metadata(None)
        assert table.schema.metadata is None

        _write_table(table, path)
        test_data.append(table)
        frames.append(df)
        paths.append(path)

    # Write _metadata common file
    table_for_metadata = pa.Table.from_pandas(
        df, preserve_index=preserve_index
    )
    pq.write_metadata(table_for_metadata.schema, dirpath / metadata_fname)

    dataset = pq.ParquetDataset(dirpath)
    columns = ['uint8', 'strings']
    result = dataset.read_pandas(columns=columns).to_pandas()
    expected = pd.concat([x[columns] for x in frames])
    expected.index.name = (
        df.index.name if preserve_index is not False else None)
    tm.assert_frame_equal(result, expected)


@pytest.mark.pandas
def test_read_pandas_passthrough_keywords(tempdir):
    # ARROW-11464 - previously not all keywords were passed through (such as
    # the filesystem keyword)
    df = pd.DataFrame({'a': [1, 2, 3]})

    filename = tempdir / 'data.parquet'
    _write_table(df, filename)

    result = pq.read_pandas(
        'data.parquet',
        filesystem=SubTreeFileSystem(str(tempdir), LocalFileSystem())
    )
    assert result.equals(pa.table(df))


@pytest.mark.pandas
def test_read_pandas_map_fields(tempdir):
    # ARROW-10140 - table created from Pandas with mapping fields
    df = pd.DataFrame({
        'col1': pd.Series([
            [('id', 'something'), ('value2', 'else')],
            [('id', 'something2'), ('value', 'else2')],
        ]),
        'col2': pd.Series(['foo', 'bar'])
    })

    filename = tempdir / 'data.parquet'

    udt = pa.map_(pa.string(), pa.string())
    schema = pa.schema([pa.field('col1', udt), pa.field('col2', pa.string())])
    arrow_table = pa.Table.from_pandas(df, schema)

    _write_table(arrow_table, filename)

    result = pq.read_pandas(filename).to_pandas()
    tm.assert_frame_equal(result, df)