Beispiel #1
0
def test_to_dataframe():
    dd = pytest.importorskip("dask.dataframe")
    pd = pytest.importorskip("pandas")

    def check_parts(df, sol):
        assert all(
            (p.dtypes == sol.dtypes).all() for p in dask.compute(*df.to_delayed())
        )

    dsk = {("test", 0): [(1, 2)], ("test", 1): [], ("test", 2): [(10, 20), (100, 200)]}
    b = Bag(dsk, "test", 3)
    sol = pd.DataFrame(b.compute(), columns=["a", "b"])

    # Elements are tuples
    df = b.to_dataframe()
    dd.utils.assert_eq(df, sol.rename(columns={"a": 0, "b": 1}), check_index=False)
    df = b.to_dataframe(columns=["a", "b"])
    dd.utils.assert_eq(df, sol, check_index=False)
    check_parts(df, sol)
    df = b.to_dataframe(meta=[("a", "i8"), ("b", "i8")])
    dd.utils.assert_eq(df, sol, check_index=False)
    check_parts(df, sol)

    # Elements are dictionaries
    b = b.map(lambda x: dict(zip(["a", "b"], x)))
    df = b.to_dataframe()
    dd.utils.assert_eq(df, sol, check_index=False)
    check_parts(df, sol)
    assert df._name == b.to_dataframe()._name

    # With metadata specified
    for meta in [sol, [("a", "i8"), ("b", "i8")]]:
        df = b.to_dataframe(meta=meta)
        dd.utils.assert_eq(df, sol, check_index=False)
        check_parts(df, sol)

    # Error to specify both columns and meta
    with pytest.raises(ValueError):
        b.to_dataframe(columns=["a", "b"], meta=sol)

    # Inference fails if empty first partition
    b2 = b.filter(lambda x: x["a"] > 200)
    with pytest.raises(ValueError):
        b2.to_dataframe()

    # Single column
    b = b.pluck("a")
    sol = sol[["a"]]
    df = b.to_dataframe(meta=sol)
    dd.utils.assert_eq(df, sol, check_index=False)
    check_parts(df, sol)

    # Works with iterators and tuples
    sol = pd.DataFrame({"a": range(100)})
    b = db.from_sequence(range(100), npartitions=5)
    for f in [iter, tuple]:
        df = b.map_partitions(f).to_dataframe(meta=sol)
        dd.utils.assert_eq(df, sol, check_index=False)
        check_parts(df, sol)
Beispiel #2
0
def test_to_dataframe():
    dd = pytest.importorskip('dask.dataframe')
    pd = pytest.importorskip('pandas')

    def check_parts(df, sol):
        assert all((p.dtypes == sol.dtypes).all() for p in
                   dask.compute(*df.to_delayed()))

    dsk = {('test', 0): [(1, 2)],
           ('test', 1): [],
           ('test', 2): [(10, 20), (100, 200)]}
    b = Bag(dsk, 'test', 3)
    sol = pd.DataFrame(b.compute(), columns=['a', 'b'])

    # Elements are tuples
    df = b.to_dataframe()
    dd.utils.assert_eq(df, sol.rename(columns={'a': 0, 'b': 1}),
                       check_index=False)
    df = b.to_dataframe(columns=['a', 'b'])
    dd.utils.assert_eq(df, sol, check_index=False)
    check_parts(df, sol)
    df = b.to_dataframe(meta=[('a', 'i8'), ('b', 'i8')])
    dd.utils.assert_eq(df, sol, check_index=False)
    check_parts(df, sol)

    # Elements are dictionaries
    b = b.map(lambda x: dict(zip(['a', 'b'], x)))
    df = b.to_dataframe()
    dd.utils.assert_eq(df, sol, check_index=False)
    check_parts(df, sol)
    assert df._name == b.to_dataframe()._name

    # With metadata specified
    for meta in [sol, [('a', 'i8'), ('b', 'i8')]]:
        df = b.to_dataframe(meta=meta)
        dd.utils.assert_eq(df, sol, check_index=False)
        check_parts(df, sol)

    # Error to specify both columns and meta
    with pytest.raises(ValueError):
        b.to_dataframe(columns=['a', 'b'], meta=sol)

    # Single column
    b = b.pluck('a')
    sol = sol[['a']]
    df = b.to_dataframe(meta=sol)
    dd.utils.assert_eq(df, sol, check_index=False)
    check_parts(df, sol)

    # Works with iterators and tuples
    sol = pd.DataFrame({'a': range(100)})
    b = db.from_sequence(range(100), npartitions=5)
    for f in [iter, tuple]:
        df = b.map_partitions(f).to_dataframe(meta=sol)
        dd.utils.assert_eq(df, sol, check_index=False)
        check_parts(df, sol)
Beispiel #3
0
def test_to_dataframe():
    dd = pytest.importorskip('dask.dataframe')
    pd = pytest.importorskip('pandas')

    def check_parts(df, sol):
        assert all((p.dtypes == sol.dtypes).all() for p in
                   dask.compute(*df.to_delayed()))

    dsk = {('test', 0): [(1, 2)],
           ('test', 1): [],
           ('test', 2): [(10, 20), (100, 200)]}
    b = Bag(dsk, 'test', 3)
    sol = pd.DataFrame(b.compute(), columns=['a', 'b'])

    # Elements are tuples
    df = b.to_dataframe()
    dd.utils.assert_eq(df, sol.rename(columns={'a': 0, 'b': 1}),
                       check_index=False)
    df = b.to_dataframe(columns=['a', 'b'])
    dd.utils.assert_eq(df, sol, check_index=False)
    check_parts(df, sol)
    df = b.to_dataframe(meta=[('a', 'i8'), ('b', 'i8')])
    dd.utils.assert_eq(df, sol, check_index=False)
    check_parts(df, sol)

    # Elements are dictionaries
    b = b.map(lambda x: dict(zip(['a', 'b'], x)))
    df = b.to_dataframe()
    dd.utils.assert_eq(df, sol, check_index=False)
    check_parts(df, sol)
    assert df._name == b.to_dataframe()._name

    # With metadata specified
    for meta in [sol, [('a', 'i8'), ('b', 'i8')]]:
        df = b.to_dataframe(meta=meta)
        dd.utils.assert_eq(df, sol, check_index=False)
        check_parts(df, sol)

    # Error to specify both columns and meta
    with pytest.raises(ValueError):
        b.to_dataframe(columns=['a', 'b'], meta=sol)

    # Single column
    b = b.pluck('a')
    sol = sol[['a']]
    df = b.to_dataframe(meta=sol)
    dd.utils.assert_eq(df, sol, check_index=False)
    check_parts(df, sol)

    # Works with iterators and tuples
    sol = pd.DataFrame({'a': range(100)})
    b = db.from_sequence(range(100), npartitions=5)
    for f in [iter, tuple]:
        df = b.map_partitions(f).to_dataframe(meta=sol)
        dd.utils.assert_eq(df, sol, check_index=False)
        check_parts(df, sol)