Function promotable_mockfs

python/pyarrow/tests/test_dataset.py:151–183

Creates a _MockFileSystem with two parquet files that have promotable schemas. - file1: value: int8, dictionary: dictionary - file2: value: uint16, dictionary: dictionary

()

@pytest.fixture
def promotable_mockfs():
    """
    Creates a _MockFileSystem with two parquet files that have promotable schemas.
    - file1: value: int8, dictionary: dictionary<int8, string>
    - file2: value: uint16, dictionary: dictionary<int16, string>
    """
    mockfs = fs._MockFileSystem()

    table1 = pa.table({
        'value': pa.array([1, 2], type=pa.int8()),
        'dictionary': pa.DictionaryArray.from_arrays(
            pa.array([0, 1], type=pa.int8()),
            ['a', 'b'],
        ),
    })
    table2 = pa.table({
        'value': pa.array([3, 4], type=pa.uint16()),
        'dictionary': pa.DictionaryArray.from_arrays(
            pa.array([1, 0], type=pa.int16()),
            ['d', 'c'],
        ),
    })

    mockfs.create_dir('subdir/zzz')
    path1 = 'subdir/zzz/file1.parquet'
    with mockfs.open_output_stream(path1) as out:
        pq.write_table(table1, out)

    path2 = 'subdir/zzz/file2.parquet'
    with mockfs.open_output_stream(path2) as out:
        pq.write_table(table2, out)

    return mockfs, path1, path2


@pytest.fixture