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from datetime import datetime
import numpy as np
import pytest
from pandas._libs.tslibs import iNaT
from pandas.compat import (
is_ci_environment,
is_platform_windows,
)
from pandas.compat.numpy import np_version_lt1p23
import pandas.util._test_decorators as td
import pandas as pd
import pandas._testing as tm
from pandas.core.interchange.column import PandasColumn
from pandas.core.interchange.dataframe_protocol import (
ColumnNullType,
DtypeKind,
)
from pandas.core.interchange.from_dataframe import from_dataframe
from pandas.core.interchange.utils import ArrowCTypes
@pytest.fixture
def data_categorical():
return {
"ordered": pd.Categorical(list("testdata") * 30, ordered=True),
"unordered": pd.Categorical(list("testdata") * 30, ordered=False),
}
@pytest.fixture
def string_data():
return {
"separator data": [
"abC|DeF,Hik",
"234,3245.67",
"gSaf,qWer|Gre",
"asd3,4sad|",
np.nan,
]
}
@pytest.mark.parametrize("data", [("ordered", True), ("unordered", False)])
def test_categorical_dtype(data, data_categorical):
df = pd.DataFrame({"A": (data_categorical[data[0]])})
col = df.__dataframe__().get_column_by_name("A")
assert col.dtype[0] == DtypeKind.CATEGORICAL
assert col.null_count == 0
assert col.describe_null == (ColumnNullType.USE_SENTINEL, -1)
assert col.num_chunks() == 1
desc_cat = col.describe_categorical
assert desc_cat["is_ordered"] == data[1]
assert desc_cat["is_dictionary"] is True
assert isinstance(desc_cat["categories"], PandasColumn)
tm.assert_series_equal(
desc_cat["categories"]._col, pd.Series(["a", "d", "e", "s", "t"])
)
tm.assert_frame_equal(df, from_dataframe(df.__dataframe__()))
def test_categorical_pyarrow():
# GH 49889
pa = pytest.importorskip("pyarrow", "11.0.0")
arr = ["Mon", "Tue", "Mon", "Wed", "Mon", "Thu", "Fri", "Sat", "Sun"]
table = pa.table({"weekday": pa.array(arr).dictionary_encode()})
exchange_df = table.__dataframe__()
result = from_dataframe(exchange_df)
weekday = pd.Categorical(
arr, categories=["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]
)
expected = pd.DataFrame({"weekday": weekday})
tm.assert_frame_equal(result, expected)
def test_empty_categorical_pyarrow():
# https://github.com/pandas-dev/pandas/issues/53077
pa = pytest.importorskip("pyarrow", "11.0.0")
arr = [None]
table = pa.table({"arr": pa.array(arr, "float64").dictionary_encode()})
exchange_df = table.__dataframe__()
result = pd.api.interchange.from_dataframe(exchange_df)
expected = pd.DataFrame({"arr": pd.Categorical([np.nan])})
tm.assert_frame_equal(result, expected)
def test_large_string_pyarrow():
# GH 52795
pa = pytest.importorskip("pyarrow", "11.0.0")
arr = ["Mon", "Tue"]
table = pa.table({"weekday": pa.array(arr, "large_string")})
exchange_df = table.__dataframe__()
result = from_dataframe(exchange_df)
expected = pd.DataFrame({"weekday": ["Mon", "Tue"]})
tm.assert_frame_equal(result, expected)
# check round-trip
assert pa.Table.equals(pa.interchange.from_dataframe(result), table)
@pytest.mark.parametrize(
("offset", "length", "expected_values"),
[
(0, None, [3.3, float("nan"), 2.1]),
(1, None, [float("nan"), 2.1]),
(2, None, [2.1]),
(0, 2, [3.3, float("nan")]),
(0, 1, [3.3]),
(1, 1, [float("nan")]),
],
)
def test_bitmasks_pyarrow(offset, length, expected_values):
# GH 52795
pa = pytest.importorskip("pyarrow", "11.0.0")
arr = [3.3, None, 2.1]
table = pa.table({"arr": arr}).slice(offset, length)
exchange_df = table.__dataframe__()
result = from_dataframe(exchange_df)
expected = pd.DataFrame({"arr": expected_values})
tm.assert_frame_equal(result, expected)
# check round-trip
assert pa.Table.equals(pa.interchange.from_dataframe(result), table)
@pytest.mark.parametrize(
"data",
[
lambda: np.random.default_rng(2).integers(-100, 100),
lambda: np.random.default_rng(2).integers(1, 100),
lambda: np.random.default_rng(2).random(),
lambda: np.random.default_rng(2).choice([True, False]),
lambda: datetime(
year=np.random.default_rng(2).integers(1900, 2100),
month=np.random.default_rng(2).integers(1, 12),
day=np.random.default_rng(2).integers(1, 20),
),
],
)
def test_dataframe(data):
NCOLS, NROWS = 10, 20
data = {
f"col{int((i - NCOLS / 2) % NCOLS + 1)}": [data() for _ in range(NROWS)]
for i in range(NCOLS)
}
df = pd.DataFrame(data)
df2 = df.__dataframe__()
assert df2.num_columns() == NCOLS
assert df2.num_rows() == NROWS
assert list(df2.column_names()) == list(data.keys())
indices = (0, 2)
names = tuple(list(data.keys())[idx] for idx in indices)
result = from_dataframe(df2.select_columns(indices))
expected = from_dataframe(df2.select_columns_by_name(names))
tm.assert_frame_equal(result, expected)
assert isinstance(result.attrs["_INTERCHANGE_PROTOCOL_BUFFERS"], list)
assert isinstance(expected.attrs["_INTERCHANGE_PROTOCOL_BUFFERS"], list)
def test_missing_from_masked():
df = pd.DataFrame(
{
"x": np.array([1.0, 2.0, 3.0, 4.0, 0.0]),
"y": np.array([1.5, 2.5, 3.5, 4.5, 0]),
"z": np.array([1.0, 0.0, 1.0, 1.0, 1.0]),
}
)
rng = np.random.default_rng(2)
dict_null = {col: rng.integers(low=0, high=len(df)) for col in df.columns}
for col, num_nulls in dict_null.items():
null_idx = df.index[
rng.choice(np.arange(len(df)), size=num_nulls, replace=False)
]
df.loc[null_idx, col] = None
df2 = df.__dataframe__()
assert df2.get_column_by_name("x").null_count == dict_null["x"]
assert df2.get_column_by_name("y").null_count == dict_null["y"]
assert df2.get_column_by_name("z").null_count == dict_null["z"]
@pytest.mark.parametrize(
"data",
[
{"x": [1.5, 2.5, 3.5], "y": [9.2, 10.5, 11.8]},
{"x": [1, 2, 0], "y": [9.2, 10.5, 11.8]},
{
"x": np.array([True, True, False]),
"y": np.array([1, 2, 0]),
"z": np.array([9.2, 10.5, 11.8]),
},
],
)
def test_mixed_data(data):
df = pd.DataFrame(data)
df2 = df.__dataframe__()
for col_name in df.columns:
assert df2.get_column_by_name(col_name).null_count == 0
def test_mixed_missing():
df = pd.DataFrame(
{
"x": np.array([True, None, False, None, True]),
"y": np.array([None, 2, None, 1, 2]),
"z": np.array([9.2, 10.5, None, 11.8, None]),
}
)
df2 = df.__dataframe__()
for col_name in df.columns:
assert df2.get_column_by_name(col_name).null_count == 2
def test_string(string_data):
test_str_data = string_data["separator data"] + [""]
df = pd.DataFrame({"A": test_str_data})
col = df.__dataframe__().get_column_by_name("A")
assert col.size() == 6
assert col.null_count == 1
assert col.dtype[0] == DtypeKind.STRING
assert col.describe_null == (ColumnNullType.USE_BYTEMASK, 0)
df_sliced = df[1:]
col = df_sliced.__dataframe__().get_column_by_name("A")
assert col.size() == 5
assert col.null_count == 1
assert col.dtype[0] == DtypeKind.STRING
assert col.describe_null == (ColumnNullType.USE_BYTEMASK, 0)
def test_nonstring_object():
df = pd.DataFrame({"A": ["a", 10, 1.0, ()]})
col = df.__dataframe__().get_column_by_name("A")
with pytest.raises(NotImplementedError, match="not supported yet"):
col.dtype
def test_datetime():
df = pd.DataFrame({"A": [pd.Timestamp("2022-01-01"), pd.NaT]})
col = df.__dataframe__().get_column_by_name("A")
assert col.size() == 2
assert col.null_count == 1
assert col.dtype[0] == DtypeKind.DATETIME
assert col.describe_null == (ColumnNullType.USE_SENTINEL, iNaT)
tm.assert_frame_equal(df, from_dataframe(df.__dataframe__()))
@pytest.mark.skipif(np_version_lt1p23, reason="Numpy > 1.23 required")
def test_categorical_to_numpy_dlpack():
# https://github.com/pandas-dev/pandas/issues/48393
df = pd.DataFrame({"A": pd.Categorical(["a", "b", "a"])})
col = df.__dataframe__().get_column_by_name("A")
result = np.from_dlpack(col.get_buffers()["data"][0])
expected = np.array([0, 1, 0], dtype="int8")
tm.assert_numpy_array_equal(result, expected)
@pytest.mark.parametrize("data", [{}, {"a": []}])
def test_empty_pyarrow(data):
# GH 53155
pytest.importorskip("pyarrow", "11.0.0")
from pyarrow.interchange import from_dataframe as pa_from_dataframe
expected = pd.DataFrame(data)
arrow_df = pa_from_dataframe(expected)
result = from_dataframe(arrow_df)
tm.assert_frame_equal(result, expected)
def test_multi_chunk_pyarrow() -> None:
pa = pytest.importorskip("pyarrow", "11.0.0")
n_legs = pa.chunked_array([[2, 2, 4], [4, 5, 100]])
names = ["n_legs"]
table = pa.table([n_legs], names=names)
with pytest.raises(
RuntimeError,
match="To join chunks a copy is required which is "
"forbidden by allow_copy=False",
):
pd.api.interchange.from_dataframe(table, allow_copy=False)
@pytest.mark.parametrize("tz", ["UTC", "US/Pacific"])
@pytest.mark.parametrize("unit", ["s", "ms", "us", "ns"])
def test_datetimetzdtype(tz, unit):
# GH 54239
tz_data = (
pd.date_range("2018-01-01", periods=5, freq="D").tz_localize(tz).as_unit(unit)
)
df = pd.DataFrame({"ts_tz": tz_data})
tm.assert_frame_equal(df, from_dataframe(df.__dataframe__()))
def test_interchange_from_non_pandas_tz_aware(request):
# GH 54239, 54287
pa = pytest.importorskip("pyarrow", "11.0.0")
import pyarrow.compute as pc
if is_platform_windows() and is_ci_environment():
mark = pytest.mark.xfail(
raises=pa.ArrowInvalid,
reason=(
"TODO: Set ARROW_TIMEZONE_DATABASE environment variable "
"on CI to path to the tzdata for pyarrow."
),
)
request.applymarker(mark)
arr = pa.array([datetime(2020, 1, 1), None, datetime(2020, 1, 2)])
arr = pc.assume_timezone(arr, "Asia/Kathmandu")
table = pa.table({"arr": arr})
exchange_df = table.__dataframe__()
result = from_dataframe(exchange_df)
expected = pd.DataFrame(
["2020-01-01 00:00:00+05:45", "NaT", "2020-01-02 00:00:00+05:45"],
columns=["arr"],
dtype="datetime64[us, Asia/Kathmandu]",
)
tm.assert_frame_equal(expected, result)
def test_interchange_from_corrected_buffer_dtypes(monkeypatch) -> None:
# https://github.com/pandas-dev/pandas/issues/54781
df = pd.DataFrame({"a": ["foo", "bar"]}).__dataframe__()
interchange = df.__dataframe__()
column = interchange.get_column_by_name("a")
buffers = column.get_buffers()
buffers_data = buffers["data"]
buffer_dtype = buffers_data[1]
buffer_dtype = (
DtypeKind.UINT,
8,
ArrowCTypes.UINT8,
buffer_dtype[3],
)
buffers["data"] = (buffers_data[0], buffer_dtype)
column.get_buffers = lambda: buffers
interchange.get_column_by_name = lambda _: column
monkeypatch.setattr(df, "__dataframe__", lambda allow_copy: interchange)
pd.api.interchange.from_dataframe(df)
def test_empty_string_column():
# https://github.com/pandas-dev/pandas/issues/56703
df = pd.DataFrame({"a": []}, dtype=str)
df2 = df.__dataframe__()
result = pd.api.interchange.from_dataframe(df2)
tm.assert_frame_equal(df, result)
def test_large_string():
# GH#56702
pytest.importorskip("pyarrow")
df = pd.DataFrame({"a": ["x"]}, dtype="large_string[pyarrow]")
result = pd.api.interchange.from_dataframe(df.__dataframe__())
expected = pd.DataFrame({"a": ["x"]}, dtype="object")
tm.assert_frame_equal(result, expected)
def test_non_str_names():
# https://github.com/pandas-dev/pandas/issues/56701
df = pd.Series([1, 2, 3], name=0).to_frame()
names = df.__dataframe__().column_names()
assert names == ["0"]
def test_non_str_names_w_duplicates():
# https://github.com/pandas-dev/pandas/issues/56701
df = pd.DataFrame({"0": [1, 2, 3], 0: [4, 5, 6]})
dfi = df.__dataframe__()
with pytest.raises(
TypeError,
match=(
"Expected a Series, got a DataFrame. This likely happened because you "
"called __dataframe__ on a DataFrame which, after converting column "
r"names to string, resulted in duplicated names: Index\(\['0', '0'\], "
r"dtype='object'\). Please rename these columns before using the "
"interchange protocol."
),
):
pd.api.interchange.from_dataframe(dfi, allow_copy=False)
@pytest.mark.parametrize(
"dtype", ["Int8", pytest.param("Int8[pyarrow]", marks=td.skip_if_no("pyarrow"))]
)
def test_nullable_integers(dtype: str) -> None:
# https://github.com/pandas-dev/pandas/issues/55069
df = pd.DataFrame({"a": [1]}, dtype=dtype)
expected = pd.DataFrame({"a": [1]}, dtype="int8")
result = pd.api.interchange.from_dataframe(df.__dataframe__())
tm.assert_frame_equal(result, expected)
def test_empty_dataframe():
# https://github.com/pandas-dev/pandas/issues/56700
df = pd.DataFrame({"a": []}, dtype="int8")
dfi = df.__dataframe__()
result = pd.api.interchange.from_dataframe(dfi, allow_copy=False)
expected = pd.DataFrame({"a": []}, dtype="int8")
tm.assert_frame_equal(result, expected)