from collections import deque
from datetime import (
    datetime,
    timezone,
)
from enum import Enum
import functools
import operator
import re

import numpy as np
import pytest

from pandas.compat._optional import import_optional_dependency

import pandas as pd
from pandas import (
    DataFrame,
    Index,
    MultiIndex,
    Series,
)
import pandas._testing as tm
from pandas.core.computation import expressions as expr
from pandas.tests.frame.common import (
    _check_mixed_float,
    _check_mixed_int,
)
from pandas.util.version import Version


@pytest.fixture
def simple_frame():
    """
    Fixture for simple 3x3 DataFrame

    Columns are ['one', 'two', 'three'], index is ['a', 'b', 'c'].

       one  two  three
    a  1.0  2.0    3.0
    b  4.0  5.0    6.0
    c  7.0  8.0    9.0
    """
    arr = np.array([[1.0, 2.0, 3.0], [4.0, 5.0, 6.0], [7.0, 8.0, 9.0]])

    return DataFrame(arr, columns=["one", "two", "three"], index=["a", "b", "c"])


@pytest.fixture(autouse=True, params=[0, 100], ids=["numexpr", "python"])
def switch_numexpr_min_elements(request, monkeypatch):
    with monkeypatch.context() as m:
        m.setattr(expr, "_MIN_ELEMENTS", request.param)
        yield request.param


class DummyElement:
    def __init__(self, value, dtype) -> None:
        self.value = value
        self.dtype = np.dtype(dtype)

    def __array__(self, dtype=None, copy=None):
        return np.array(self.value, dtype=self.dtype)

    def __str__(self) -> str:
        return f"DummyElement({self.value}, {self.dtype})"

    def __repr__(self) -> str:
        return str(self)

    def astype(self, dtype, copy=False):
        self.dtype = dtype
        return self

    def view(self, dtype):
        return type(self)(self.value.view(dtype), dtype)

    def any(self, axis=None):
        return bool(self.value)


# -------------------------------------------------------------------
# Comparisons


class TestFrameComparisons:
    # Specifically _not_ flex-comparisons

    def test_comparison_with_categorical_dtype(self):
        # GH#12564

        df = DataFrame({"A": ["foo", "bar", "baz"]})
        exp = DataFrame({"A": [True, False, False]})

        res = df == "foo"
        tm.assert_frame_equal(res, exp)

        # casting to categorical shouldn't affect the result
        df["A"] = df["A"].astype("category")

        res = df == "foo"
        tm.assert_frame_equal(res, exp)

    def test_frame_in_list(self):
        # GH#12689 this should raise at the DataFrame level, not blocks
        df = DataFrame(
            np.random.default_rng(2).standard_normal((6, 4)), columns=list("ABCD")
        )
        msg = "The truth value of a DataFrame is ambiguous"
        with pytest.raises(ValueError, match=msg):
            df in [None]

    @pytest.mark.parametrize(
        "arg, arg2",
        [
            [
                {
                    "a": np.random.default_rng(2).integers(10, size=10),
                    "b": pd.date_range("20010101", periods=10, unit="ns"),
                },
                {
                    "a": np.random.default_rng(2).integers(10, size=10),
                    "b": np.random.default_rng(2).integers(10, size=10),
                },
            ],
            [
                {
                    "a": np.random.default_rng(2).integers(10, size=10),
                    "b": np.random.default_rng(2).integers(10, size=10),
                },
                {
                    "a": np.random.default_rng(2).integers(10, size=10),
                    "b": pd.date_range("20010101", periods=10, unit="ns"),
                },
            ],
            [
                {
                    "a": pd.date_range("20010101", periods=10, unit="ns"),
                    "b": pd.date_range("20010101", periods=10, unit="ns"),
                },
                {
                    "a": np.random.default_rng(2).integers(10, size=10),
                    "b": np.random.default_rng(2).integers(10, size=10),
                },
            ],
            [
                {
                    "a": np.random.default_rng(2).integers(10, size=10),
                    "b": pd.date_range("20010101", periods=10, unit="ns"),
                },
                {
                    "a": pd.date_range("20010101", periods=10, unit="ns"),
                    "b": pd.date_range("20010101", periods=10, unit="ns"),
                },
            ],
        ],
    )
    def test_comparison_invalid(self, arg, arg2):
        # GH4968
        # invalid date/int comparisons
        x = DataFrame(arg)
        y = DataFrame(arg2)
        # we expect the result to match Series comparisons for
        # == and !=, inequalities should raise
        result = x == y
        expected = DataFrame(
            {col: x[col] == y[col] for col in x.columns},
            index=x.index,
            columns=x.columns,
        )
        tm.assert_frame_equal(result, expected)

        result = x != y
        expected = DataFrame(
            {col: x[col] != y[col] for col in x.columns},
            index=x.index,
            columns=x.columns,
        )
        tm.assert_frame_equal(result, expected)

        msgs = [
            r"Invalid comparison between dtype=datetime64\[ns\] and ndarray",
            "invalid type promotion",
            (
                # npdev 1.20.0
                r"The DTypes <class 'numpy.dtype\[.*\]'> and "
                r"<class 'numpy.dtype\[.*\]'> do not have a common DType."
            ),
        ]
        msg = "|".join(msgs)
        with pytest.raises(TypeError, match=msg):
            x >= y
        with pytest.raises(TypeError, match=msg):
            x > y
        with pytest.raises(TypeError, match=msg):
            x < y
        with pytest.raises(TypeError, match=msg):
            x <= y

    @pytest.mark.parametrize(
        "left, right",
        [
            ("gt", "lt"),
            ("lt", "gt"),
            ("ge", "le"),
            ("le", "ge"),
            ("eq", "eq"),
            ("ne", "ne"),
        ],
    )
    def test_timestamp_compare(self, left, right):
        # make sure we can compare Timestamps on the right AND left hand side
        # GH#4982
        df = DataFrame(
            {
                "dates1": pd.date_range("20010101", periods=10),
                "dates2": pd.date_range("20010102", periods=10),
                "intcol": np.random.default_rng(2).integers(1000000000, size=10),
                "floatcol": np.random.default_rng(2).standard_normal(10),
                "stringcol": [chr(100 + i) for i in range(10)],
            }
        )
        df.loc[np.random.default_rng(2).random(len(df)) > 0.5, "dates2"] = pd.NaT
        left_f = getattr(operator, left)
        right_f = getattr(operator, right)

        # no nats
        if left in ["eq", "ne"]:
            expected = left_f(df, pd.Timestamp("20010109"))
            result = right_f(pd.Timestamp("20010109"), df)
            tm.assert_frame_equal(result, expected)
        else:
            msg = (
                "'(<|>)=?' not supported between "
                "instances of 'numpy.ndarray' and 'Timestamp'"
            )
            with pytest.raises(TypeError, match=msg):
                left_f(df, pd.Timestamp("20010109"))
            with pytest.raises(TypeError, match=msg):
                right_f(pd.Timestamp("20010109"), df)
        # nats
        if left in ["eq", "ne"]:
            expected = left_f(df, pd.Timestamp("nat"))
            result = right_f(pd.Timestamp("nat"), df)
            tm.assert_frame_equal(result, expected)
        else:
            msg = (
                "'(<|>)=?' not supported between "
                "instances of 'numpy.ndarray' and 'NaTType'"
            )
            with pytest.raises(TypeError, match=msg):
                left_f(df, pd.Timestamp("nat"))
            with pytest.raises(TypeError, match=msg):
                right_f(pd.Timestamp("nat"), df)

    def test_mixed_comparison(self):
        # GH#13128, GH#22163 != datetime64 vs non-dt64 should be False,
        # not raise TypeError
        # (this appears to be fixed before GH#22163, not sure when)
        df = DataFrame([["1989-08-01", 1], ["1989-08-01", 2]])
        other = DataFrame([["a", "b"], ["c", "d"]])

        result = df == other
        assert not result.any().any()

        result = df != other
        assert result.all().all()

    def test_df_boolean_comparison_error(self):
        # GH#4576, GH#22880
        # comparing DataFrame against list/tuple with len(obj) matching
        #  len(df.columns) is supported as of GH#22800
        df = DataFrame(np.arange(6).reshape((3, 2)))

        expected = DataFrame([[False, False], [True, False], [False, False]])

        result = df == (2, 2)
        tm.assert_frame_equal(result, expected)

        result = df == [2, 2]
        tm.assert_frame_equal(result, expected)

    def test_df_float_none_comparison(self):
        df = DataFrame(
            np.random.default_rng(2).standard_normal((8, 3)),
            index=range(8),
            columns=["A", "B", "C"],
        )

        result = df.__eq__(None)
        assert not result.any().any()

    def test_df_string_comparison(self):
        df = DataFrame([{"a": 1, "b": "foo"}, {"a": 2, "b": "bar"}])
        mask_a = df.a > 1
        tm.assert_frame_equal(df[mask_a], df.loc[1:1, :])
        tm.assert_frame_equal(df[-mask_a], df.loc[0:0, :])

        mask_b = df.b == "foo"
        tm.assert_frame_equal(df[mask_b], df.loc[0:0, :])
        tm.assert_frame_equal(df[-mask_b], df.loc[1:1, :])


class TestFrameFlexComparisons:
    # TODO: test_bool_flex_frame needs a better name
    def test_bool_flex_frame(self, comparison_op):
        data = np.random.default_rng(2).standard_normal((5, 3))
        other_data = np.random.default_rng(2).standard_normal((5, 3))
        df = DataFrame(data)
        other = DataFrame(other_data)
        ndim_5 = np.ones((*df.shape, 1, 3))

        # DataFrame
        assert df.eq(df).values.all()
        assert not df.ne(df).values.any()
        f = getattr(df, comparison_op.__name__)
        o = comparison_op
        # No NAs
        tm.assert_frame_equal(f(other), o(df, other))
        # Unaligned
        part_o = other.loc[3:, 1:].copy()
        rs = f(part_o)
        xp = o(df, part_o.reindex(index=df.index, columns=df.columns))
        tm.assert_frame_equal(rs, xp)
        # ndarray
        tm.assert_frame_equal(f(other.values), o(df, other.values))
        # scalar
        tm.assert_frame_equal(f(0), o(df, 0))
        # NAs
        msg = "Unable to coerce to Series/DataFrame"
        tm.assert_frame_equal(f(np.nan), o(df, np.nan))
        with pytest.raises(ValueError, match=msg):
            f(ndim_5)

    @pytest.mark.parametrize("box", [np.array, Series])
    def test_bool_flex_series(self, box):
        # Series
        # list/tuple
        data = np.random.default_rng(2).standard_normal((5, 3))
        df = DataFrame(data)
        idx_ser = box(np.random.default_rng(2).standard_normal(5))
        col_ser = box(np.random.default_rng(2).standard_normal(3))

        idx_eq = df.eq(idx_ser, axis=0)
        col_eq = df.eq(col_ser)
        idx_ne = df.ne(idx_ser, axis=0)
        col_ne = df.ne(col_ser)
        tm.assert_frame_equal(col_eq, df == Series(col_ser))
        tm.assert_frame_equal(col_eq, -col_ne)
        tm.assert_frame_equal(idx_eq, -idx_ne)
        tm.assert_frame_equal(idx_eq, df.T.eq(idx_ser).T)
        tm.assert_frame_equal(col_eq, df.eq(list(col_ser)))
        tm.assert_frame_equal(idx_eq, df.eq(Series(idx_ser), axis=0))
        tm.assert_frame_equal(idx_eq, df.eq(list(idx_ser), axis=0))

        idx_gt = df.gt(idx_ser, axis=0)
        col_gt = df.gt(col_ser)
        idx_le = df.le(idx_ser, axis=0)
        col_le = df.le(col_ser)

        tm.assert_frame_equal(col_gt, df > Series(col_ser))
        tm.assert_frame_equal(col_gt, -col_le)
        tm.assert_frame_equal(idx_gt, -idx_le)
        tm.assert_frame_equal(idx_gt, df.T.gt(idx_ser).T)

        idx_ge = df.ge(idx_ser, axis=0)
        col_ge = df.ge(col_ser)
        idx_lt = df.lt(idx_ser, axis=0)
        col_lt = df.lt(col_ser)
        tm.assert_frame_equal(col_ge, df >= Series(col_ser))
        tm.assert_frame_equal(col_ge, -col_lt)
        tm.assert_frame_equal(idx_ge, -idx_lt)
        tm.assert_frame_equal(idx_ge, df.T.ge(idx_ser).T)

        idx_ser = Series(np.random.default_rng(2).standard_normal(5))
        col_ser = Series(np.random.default_rng(2).standard_normal(3))

    def test_bool_flex_frame_na(self):
        df = DataFrame(np.random.default_rng(2).standard_normal((5, 3)))
        # NA
        df.loc[0, 0] = np.nan
        rs = df.eq(df)
        assert not rs.loc[0, 0]
        rs = df.ne(df)
        assert rs.loc[0, 0]
        rs = df.gt(df)
        assert not rs.loc[0, 0]
        rs = df.lt(df)
        assert not rs.loc[0, 0]
        rs = df.ge(df)
        assert not rs.loc[0, 0]
        rs = df.le(df)
        assert not rs.loc[0, 0]

    def test_bool_flex_frame_complex_dtype(self):
        # complex
        arr = np.array([np.nan, 1, 6, np.nan])
        arr2 = np.array([2j, np.nan, 7, None])
        df = DataFrame({"a": arr})
        df2 = DataFrame({"a": arr2})

        msg = "|".join(
            [
                "'>' not supported between instances of '.*' and 'complex'",
                r"unorderable types: .*complex\(\)",  # PY35
            ]
        )
        with pytest.raises(TypeError, match=msg):
            # inequalities are not well-defined for complex numbers
            df.gt(df2)
        with pytest.raises(TypeError, match=msg):
            # regression test that we get the same behavior for Series
            df["a"].gt(df2["a"])
        with pytest.raises(TypeError, match=msg):
            # Check that we match numpy behavior here
            df.values > df2.values

        rs = df.ne(df2)
        assert rs.values.all()

        arr3 = np.array([2j, np.nan, None])
        df3 = DataFrame({"a": arr3})

        with pytest.raises(TypeError, match=msg):
            # inequalities are not well-defined for complex numbers
            df3.gt(2j)
        with pytest.raises(TypeError, match=msg):
            # regression test that we get the same behavior for Series
            df3["a"].gt(2j)
        with pytest.raises(TypeError, match=msg):
            # Check that we match numpy behavior here
            df3.values > 2j

    def test_bool_flex_frame_object_dtype(self):
        # corner, dtype=object
        df1 = DataFrame({"col": ["foo", np.nan, "bar"]}, dtype=object)
        df2 = DataFrame({"col": ["foo", datetime.now(), "bar"]}, dtype=object)
        result = df1.ne(df2)
        exp = DataFrame({"col": [False, True, False]})
        tm.assert_frame_equal(result, exp)

    def test_flex_comparison_nat(self):
        # GH 15697, GH 22163 df.eq(pd.NaT) should behave like df == pd.NaT,
        # and _definitely_ not be NaN
        df = DataFrame([pd.NaT])

        result = df == pd.NaT
        # result.iloc[0, 0] is an np.bool_ object
        assert result.iloc[0, 0].item() is False

        result = df.eq(pd.NaT)
        assert result.iloc[0, 0].item() is False

        result = df != pd.NaT
        assert result.iloc[0, 0].item() is True

        result = df.ne(pd.NaT)
        assert result.iloc[0, 0].item() is True

    def test_df_flex_cmp_constant_return_types(self, comparison_op):
        # GH 15077, non-empty DataFrame
        df = DataFrame({"x": [1, 2, 3], "y": [1.0, 2.0, 3.0]})
        const = 2

        result = getattr(df, comparison_op.__name__)(const).dtypes.value_counts()
        tm.assert_series_equal(
            result, Series([2], index=[np.dtype(bool)], name="count")
        )

    def test_df_flex_cmp_constant_return_types_empty(self, comparison_op):
        # GH 15077 empty DataFrame
        df = DataFrame({"x": [1, 2, 3], "y": [1.0, 2.0, 3.0]})
        const = 2

        empty = df.iloc[:0]
        result = getattr(empty, comparison_op.__name__)(const).dtypes.value_counts()
        tm.assert_series_equal(
            result, Series([2], index=[np.dtype(bool)], name="count")
        )

    def test_df_flex_cmp_ea_dtype_with_ndarray_series(self):
        ii = pd.IntervalIndex.from_breaks([1, 2, 3])
        df = DataFrame({"A": ii, "B": ii})

        ser = Series([0, 0])
        res = df.eq(ser, axis=0)

        expected = DataFrame({"A": [False, False], "B": [False, False]})
        tm.assert_frame_equal(res, expected)

        ser2 = Series([1, 2], index=["A", "B"])
        res2 = df.eq(ser2, axis=1)
        tm.assert_frame_equal(res2, expected)


# -------------------------------------------------------------------
# Arithmetic


class TestFrameFlexArithmetic:
    def test_floordiv_axis0(self):
        # make sure we df.floordiv(ser, axis=0) matches column-wise result
        arr = np.arange(3)
        ser = Series(arr)
        df = DataFrame({"A": ser, "B": ser})

        result = df.floordiv(ser, axis=0)

        expected = DataFrame({col: df[col] // ser for col in df.columns})

        tm.assert_frame_equal(result, expected)

        result2 = df.floordiv(ser.values, axis=0)
        tm.assert_frame_equal(result2, expected)

    def test_df_add_td64_columnwise(self):
        # GH 22534 Check that column-wise addition broadcasts correctly
        dti = pd.date_range("2016-01-01", periods=10)
        tdi = pd.timedelta_range("1", periods=10)
        tser = Series(tdi)
        df = DataFrame({0: dti, 1: tdi})

        result = df.add(tser, axis=0)
        expected = DataFrame({0: dti + tdi, 1: tdi + tdi})
        tm.assert_frame_equal(result, expected)

    def test_df_add_flex_filled_mixed_dtypes(self):
        # GH 19611
        dti = pd.date_range("2016-01-01", periods=3)
        ser = Series(["1 Day", "NaT", "2 Days"], dtype="timedelta64[ns]")
        df = DataFrame({"A": dti, "B": ser})
        other = DataFrame({"A": ser, "B": ser})
        fill = pd.Timedelta(days=1).to_timedelta64()
        result = df.add(other, fill_value=fill)

        expected = DataFrame(
            {
                "A": Series(
                    ["2016-01-02", "2016-01-03", "2016-01-05"], dtype="datetime64[ns]"
                ),
                "B": ser * 2,
            }
        )
        tm.assert_frame_equal(result, expected)

    def test_arith_flex_frame(
        self, all_arithmetic_operators, float_frame, mixed_float_frame
    ):
        # one instance of parametrized fixture
        op = all_arithmetic_operators

        def f(x, y):
            # r-versions not in operator-stdlib; get op without "r" and invert
            if op.startswith("__r"):
                return getattr(operator, op.replace("__r", "__"))(y, x)
            return getattr(operator, op)(x, y)

        result = getattr(float_frame, op)(2 * float_frame)
        expected = f(float_frame, 2 * float_frame)
        tm.assert_frame_equal(result, expected)

        # vs mix float
        result = getattr(mixed_float_frame, op)(2 * mixed_float_frame)
        expected = f(mixed_float_frame, 2 * mixed_float_frame)
        tm.assert_frame_equal(result, expected)
        _check_mixed_float(result, dtype={"C": None})

    @pytest.mark.parametrize("op", ["__add__", "__sub__", "__mul__"])
    def test_arith_flex_frame_mixed(
        self,
        op,
        int_frame,
        mixed_int_frame,
        mixed_float_frame,
        switch_numexpr_min_elements,
    ):
        f = getattr(operator, op)

        # vs mix int
        result = getattr(mixed_int_frame, op)(2 + mixed_int_frame)
        expected = f(mixed_int_frame, 2 + mixed_int_frame)

        # no overflow in the uint
        dtype = None
        if op in ["__sub__"]:
            dtype = {"B": "uint64", "C": None}
        elif op in ["__add__", "__mul__"]:
            dtype = {"C": None}
        if expr.USE_NUMEXPR and switch_numexpr_min_elements == 0:
            # when using numexpr, the casting rules are slightly different:
            # in the `2 + mixed_int_frame` operation, int32 column becomes
            # and int64 column (not preserving dtype in operation with Python
            # scalar), and then the int32/int64 combo results in int64 result
            dtype["A"] = (2 + mixed_int_frame)["A"].dtype
        tm.assert_frame_equal(result, expected)
        _check_mixed_int(result, dtype=dtype)

        # vs mix float
        result = getattr(mixed_float_frame, op)(2 * mixed_float_frame)
        expected = f(mixed_float_frame, 2 * mixed_float_frame)
        tm.assert_frame_equal(result, expected)
        _check_mixed_float(result, dtype={"C": None})

        # vs plain int
        result = getattr(int_frame, op)(2 * int_frame)
        expected = f(int_frame, 2 * int_frame)
        tm.assert_frame_equal(result, expected)

    @pytest.mark.parametrize("dim", range(3, 6))
    def test_arith_flex_frame_raise(self, all_arithmetic_operators, float_frame, dim):
        # one instance of parametrized fixture
        op = all_arithmetic_operators

        # Check that arrays with dim >= 3 raise
        arr = np.ones((1,) * dim)
        msg = "Unable to coerce to Series/DataFrame"
        with pytest.raises(ValueError, match=msg):
            getattr(float_frame, op)(arr)

    def test_arith_flex_frame_corner(self, float_frame):
        const_add = float_frame.add(1)
        tm.assert_frame_equal(const_add, float_frame + 1)

        # corner cases
        result = float_frame.add(float_frame[:0])
        expected = float_frame.sort_index() * np.nan
        tm.assert_frame_equal(result, expected)

        result = float_frame[:0].add(float_frame)
        expected = float_frame.sort_index() * np.nan
        tm.assert_frame_equal(result, expected)

        with pytest.raises(NotImplementedError, match="fill_value"):
            float_frame.add(float_frame.iloc[0], fill_value=3)

        with pytest.raises(NotImplementedError, match="fill_value"):
            float_frame.add(float_frame.iloc[0], axis="index", fill_value=3)

    @pytest.mark.parametrize("op", ["add", "sub", "mul", "mod"])
    def test_arith_flex_series_ops(self, simple_frame, op):
        # after arithmetic refactor, add truediv here
        df = simple_frame

        row = df.xs("a")
        col = df["two"]
        f = getattr(df, op)
        op = getattr(operator, op)
        tm.assert_frame_equal(f(row), op(df, row))
        tm.assert_frame_equal(f(col, axis=0), op(df.T, col).T)

    def test_arith_flex_series(self, simple_frame):
        df = simple_frame

        row = df.xs("a")
        col = df["two"]
        # special case for some reason
        tm.assert_frame_equal(df.add(row, axis=None), df + row)

        # cases which will be refactored after big arithmetic refactor
        tm.assert_frame_equal(df.div(row), df / row)
        tm.assert_frame_equal(df.div(col, axis=0), (df.T / col).T)

    def test_arith_flex_series_broadcasting(self, any_real_numpy_dtype):
        # broadcasting issue in GH 7325
        df = DataFrame(np.arange(3 * 2).reshape((3, 2)), dtype=any_real_numpy_dtype)
        expected = DataFrame([[np.nan, np.inf], [1.0, 1.5], [1.0, 1.25]])
        if any_real_numpy_dtype == "float32":
            expected = expected.astype(any_real_numpy_dtype)
        result = df.div(df[0], axis="index")
        tm.assert_frame_equal(result, expected)

    def test_arith_flex_zero_len_raises(self):
        # GH 19522 passing fill_value to frame flex arith methods should
        # raise even in the zero-length special cases
        ser_len0 = Series([], dtype=object)
        df_len0 = DataFrame(columns=["A", "B"])
        df = DataFrame([[1, 2], [3, 4]], columns=["A", "B"])

        with pytest.raises(NotImplementedError, match="fill_value"):
            df.add(ser_len0, fill_value="E")

        with pytest.raises(NotImplementedError, match="fill_value"):
            df_len0.sub(df["A"], axis=None, fill_value=3)

    def test_flex_add_scalar_fill_value(self):
        # GH#12723
        dat = np.array([0, 1, np.nan, 3, 4, 5], dtype="float")
        df = DataFrame({"foo": dat}, index=range(6))

        exp = df.fillna(0).add(2)
        res = df.add(2, fill_value=0)
        tm.assert_frame_equal(res, exp)

    def test_sub_alignment_with_duplicate_index(self):
        # GH#5185 dup aligning operations should work
        df1 = DataFrame([1, 2, 3, 4, 5], index=[1, 2, 1, 2, 3])
        df2 = DataFrame([1, 2, 3], index=[1, 2, 3])
        expected = DataFrame([0, 2, 0, 2, 2], index=[1, 1, 2, 2, 3])
        result = df1.sub(df2)
        tm.assert_frame_equal(result, expected)

    @pytest.mark.parametrize("op", ["__add__", "__mul__", "__sub__", "__truediv__"])
    def test_arithmetic_with_duplicate_columns(self, op):
        # operations
        df = DataFrame({"A": np.arange(10), "B": np.random.default_rng(2).random(10)})
        expected = getattr(df, op)(df)
        expected.columns = ["A", "A"]
        df.columns = ["A", "A"]
        result = getattr(df, op)(df)
        tm.assert_frame_equal(result, expected)

    @pytest.mark.parametrize("level", [0, None])
    def test_broadcast_multiindex(self, level):
        # GH34388
        df1 = DataFrame({"A": [0, 1, 2], "B": [1, 2, 3]})
        df1.columns = df1.columns.set_names("L1")

        df2 = DataFrame({("A", "C"): [0, 0, 0], ("A", "D"): [0, 0, 0]})
        df2.columns = df2.columns.set_names(["L1", "L2"])

        result = df1.add(df2, level=level)
        expected = DataFrame({("A", "C"): [0, 1, 2], ("A", "D"): [0, 1, 2]})
        expected.columns = expected.columns.set_names(["L1", "L2"])

        tm.assert_frame_equal(result, expected)

    def test_frame_multiindex_operations(self):
        # GH 43321
        df = DataFrame(
            {2010: [1, 2, 3], 2020: [3, 4, 5]},
            index=MultiIndex.from_product(
                [["a"], ["b"], [0, 1, 2]], names=["scen", "mod", "id"]
            ),
        )

        series = Series(
            [0.4],
            index=MultiIndex.from_product([["b"], ["a"]], names=["mod", "scen"]),
        )

        expected = DataFrame(
            {2010: [1.4, 2.4, 3.4], 2020: [3.4, 4.4, 5.4]},
            index=MultiIndex.from_product(
                [["a"], ["b"], [0, 1, 2]], names=["scen", "mod", "id"]
            ),
        )
        result = df.add(series, axis=0)

        tm.assert_frame_equal(result, expected)

    def test_frame_multiindex_operations_series_index_to_frame_index(self):
        # GH 43321
        df = DataFrame(
            {2010: [1], 2020: [3]},
            index=MultiIndex.from_product([["a"], ["b"]], names=["scen", "mod"]),
        )

        series = Series(
            [10.0, 20.0, 30.0],
            index=MultiIndex.from_product(
                [["a"], ["b"], [0, 1, 2]], names=["scen", "mod", "id"]
            ),
        )

        expected = DataFrame(
            {2010: [11.0, 21, 31.0], 2020: [13.0, 23.0, 33.0]},
            index=MultiIndex.from_product(
                [["a"], ["b"], [0, 1, 2]], names=["scen", "mod", "id"]
            ),
        )
        result = df.add(series, axis=0)

        tm.assert_frame_equal(result, expected)

    def test_frame_multiindex_operations_no_align(self):
        df = DataFrame(
            {2010: [1, 2, 3], 2020: [3, 4, 5]},
            index=MultiIndex.from_product(
                [["a"], ["b"], [0, 1, 2]], names=["scen", "mod", "id"]
            ),
        )

        series = Series(
            [0.4],
            index=MultiIndex.from_product([["c"], ["a"]], names=["mod", "scen"]),
        )

        expected = DataFrame(
            {2010: np.nan, 2020: np.nan},
            index=MultiIndex.from_tuples(
                [
                    ("a", "b", 0),
                    ("a", "b", 1),
                    ("a", "b", 2),
                    ("a", "c", np.nan),
                ],
                names=["scen", "mod", "id"],
            ),
        )
        result = df.add(series, axis=0)

        tm.assert_frame_equal(result, expected)

    def test_frame_multiindex_operations_part_align(self):
        df = DataFrame(
            {2010: [1, 2, 3], 2020: [3, 4, 5]},
            index=MultiIndex.from_tuples(
                [
                    ("a", "b", 0),
                    ("a", "b", 1),
                    ("a", "c", 2),
                ],
                names=["scen", "mod", "id"],
            ),
        )

        series = Series(
            [0.4],
            index=MultiIndex.from_product([["b"], ["a"]], names=["mod", "scen"]),
        )

        expected = DataFrame(
            {2010: [1.4, 2.4, np.nan], 2020: [3.4, 4.4, np.nan]},
            index=MultiIndex.from_tuples(
                [
                    ("a", "b", 0),
                    ("a", "b", 1),
                    ("a", "c", 2),
                ],
                names=["scen", "mod", "id"],
            ),
        )
        result = df.add(series, axis=0)

        tm.assert_frame_equal(result, expected)

    def test_frame_multiindex_operations_part_align_axis1(self):
        # GH#61009 Test DataFrame-Series arithmetic operation
        # with partly aligned MultiIndex and axis = 1
        df = DataFrame(
            [[1, 2, 3], [3, 4, 5]],
            index=[2010, 2020],
            columns=MultiIndex.from_tuples(
                [
                    ("a", "b", 0),
                    ("a", "b", 1),
                    ("a", "c", 2),
                ],
                names=["scen", "mod", "id"],
            ),
        )

        series = Series(
            [0.4],
            index=MultiIndex.from_product([["b"], ["a"]], names=["mod", "scen"]),
        )

        expected = DataFrame(
            [[1.4, 2.4, np.nan], [3.4, 4.4, np.nan]],
            index=[2010, 2020],
            columns=MultiIndex.from_tuples(
                [
                    ("a", "b", 0),
                    ("a", "b", 1),
                    ("a", "c", 2),
                ],
                names=["scen", "mod", "id"],
            ),
        )
        result = df.add(series, axis=1)

        tm.assert_frame_equal(result, expected)


class TestFrameArithmetic:
    def test_td64_op_nat_casting(self):
        # Make sure we don't accidentally treat timedelta64(NaT) as datetime64
        #  when calling dispatch_to_series in DataFrame arithmetic
        ser = Series(["NaT", "NaT"], dtype="timedelta64[ns]")
        df = DataFrame([[1, 2], [3, 4]])

        result = df * ser
        expected = DataFrame({0: ser, 1: ser})
        tm.assert_frame_equal(result, expected)

    def test_df_add_2d_array_rowlike_broadcasts(self):
        # GH#23000
        arr = np.arange(6).reshape(3, 2)
        df = DataFrame(arr, columns=[True, False], index=["A", "B", "C"])

        rowlike = arr[[1], :]  # shape --> (1, ncols)
        assert rowlike.shape == (1, df.shape[1])

        expected = DataFrame(
            [[2, 4], [4, 6], [6, 8]],
            columns=df.columns,
            index=df.index,
            # specify dtype explicitly to avoid failing
            # on 32bit builds
            dtype=arr.dtype,
        )
        result = df + rowlike
        tm.assert_frame_equal(result, expected)
        result = rowlike + df
        tm.assert_frame_equal(result, expected)

    def test_df_add_2d_array_collike_broadcasts(self):
        # GH#23000
        arr = np.arange(6).reshape(3, 2)
        df = DataFrame(arr, columns=[True, False], index=["A", "B", "C"])

        collike = arr[:, [1]]  # shape --> (nrows, 1)
        assert collike.shape == (df.shape[0], 1)

        expected = DataFrame(
            [[1, 2], [5, 6], [9, 10]],
            columns=df.columns,
            index=df.index,
            # specify dtype explicitly to avoid failing
            # on 32bit builds
            dtype=arr.dtype,
        )
        result = df + collike
        tm.assert_frame_equal(result, expected)
        result = collike + df
        tm.assert_frame_equal(result, expected)

    def test_df_arith_2d_array_rowlike_broadcasts(
        self, request, all_arithmetic_operators
    ):
        # GH#23000
        opname = all_arithmetic_operators
        arr = np.arange(6).reshape(3, 2)
        df = DataFrame(arr, columns=[True, False], index=["A", "B", "C"])

        rowlike = arr[[1], :]  # shape --> (1, ncols)
        assert rowlike.shape == (1, df.shape[1])

        exvals = [
            getattr(df.loc["A"], opname)(rowlike.squeeze()),
            getattr(df.loc["B"], opname)(rowlike.squeeze()),
            getattr(df.loc["C"], opname)(rowlike.squeeze()),
        ]

        expected = DataFrame(exvals, columns=df.columns, index=df.index)

        result = getattr(df, opname)(rowlike)
        tm.assert_frame_equal(result, expected)

    def test_df_arith_2d_array_collike_broadcasts(
        self, request, all_arithmetic_operators
    ):
        # GH#23000
        opname = all_arithmetic_operators
        arr = np.arange(6).reshape(3, 2)
        df = DataFrame(arr, columns=[True, False], index=["A", "B", "C"])

        collike = arr[:, [1]]  # shape --> (nrows, 1)
        assert collike.shape == (df.shape[0], 1)

        exvals = {
            True: getattr(df[True], opname)(collike.squeeze()),
            False: getattr(df[False], opname)(collike.squeeze()),
        }

        dtype = None
        if opname in ["__rmod__", "__rfloordiv__"]:
            # Series ops may return mixed int/float dtypes in cases where
            #   DataFrame op will return all-float.  So we upcast `expected`
            dtype = np.common_type(*(x.values for x in exvals.values()))

        expected = DataFrame(exvals, columns=df.columns, index=df.index, dtype=dtype)

        result = getattr(df, opname)(collike)
        tm.assert_frame_equal(result, expected)

    def test_df_bool_mul_int(self):
        # GH 22047, GH 22163 multiplication by 1 should result in int dtype,
        # not object dtype
        df = DataFrame([[False, True], [False, False]])
        result = df * 1

        # On appveyor this comes back as np.int32 instead of np.int64,
        # so we check dtype.kind instead of just dtype
        kinds = result.dtypes.apply(lambda x: x.kind)
        assert (kinds == "i").all()

        result = 1 * df
        kinds = result.dtypes.apply(lambda x: x.kind)
        assert (kinds == "i").all()

    def test_arith_mixed(self):
        left = DataFrame({"A": ["a", "b", "c"], "B": [1, 2, 3]})

        result = left + left
        expected = DataFrame({"A": ["aa", "bb", "cc"], "B": [2, 4, 6]})
        tm.assert_frame_equal(result, expected)

    @pytest.mark.parametrize("col", ["A", "B"])
    def test_arith_getitem_commute(self, all_arithmetic_functions, col):
        df = DataFrame({"A": [1.1, 3.3], "B": [2.5, -3.9]})
        result = all_arithmetic_functions(df, 1)[col]
        expected = all_arithmetic_functions(df[col], 1)
        tm.assert_series_equal(result, expected)

    @pytest.mark.parametrize(
        "values", [[1, 2], (1, 2), np.array([1, 2]), range(1, 3), deque([1, 2])]
    )
    def test_arith_alignment_non_pandas_object(self, values):
        # GH#17901
        df = DataFrame({"A": [1, 1], "B": [1, 1]})
        expected = DataFrame({"A": [2, 2], "B": [3, 3]})
        result = df + values
        tm.assert_frame_equal(result, expected)

    def test_arith_non_pandas_object(self):
        df = DataFrame(
            np.arange(1, 10, dtype="f8").reshape(3, 3),
            columns=["one", "two", "three"],
            index=["a", "b", "c"],
        )

        val1 = df.xs("a").values
        added = DataFrame(df.values + val1, index=df.index, columns=df.columns)
        tm.assert_frame_equal(df + val1, added)

        added = DataFrame((df.values.T + val1).T, index=df.index, columns=df.columns)
        tm.assert_frame_equal(df.add(val1, axis=0), added)

        val2 = list(df["two"])

        added = DataFrame(df.values + val2, index=df.index, columns=df.columns)
        tm.assert_frame_equal(df + val2, added)

        added = DataFrame((df.values.T + val2).T, index=df.index, columns=df.columns)
        tm.assert_frame_equal(df.add(val2, axis="index"), added)

        val3 = np.random.default_rng(2).random(df.shape)
        added = DataFrame(df.values + val3, index=df.index, columns=df.columns)
        tm.assert_frame_equal(df.add(val3), added)

    def test_operations_with_interval_categories_index(self, all_arithmetic_operators):
        # GH#27415
        op = all_arithmetic_operators
        ind = pd.CategoricalIndex(pd.interval_range(start=0.0, end=2.0))
        data = [1, 2]
        df = DataFrame([data], columns=ind)
        num = 10
        result = getattr(df, op)(num)
        expected = DataFrame([[getattr(n, op)(num) for n in data]], columns=ind)
        tm.assert_frame_equal(result, expected)

    def test_frame_with_frame_reindex(self):
        # GH#31623
        df = DataFrame(
            {
                "foo": [pd.Timestamp("2019"), pd.Timestamp("2020")],
                "bar": [pd.Timestamp("2018"), pd.Timestamp("2021")],
            },
            columns=["foo", "bar"],
            dtype="M8[ns]",
        )
        df2 = df[["foo"]]

        result = df - df2

        expected = DataFrame(
            {"foo": [pd.Timedelta(0), pd.Timedelta(0)], "bar": [np.nan, np.nan]},
            columns=["bar", "foo"],
        )
        tm.assert_frame_equal(result, expected)

    @pytest.mark.parametrize(
        "value, dtype",
        [
            (1, "i8"),
            (1.0, "f8"),
            (2**63, "f8"),
            (1j, "complex128"),
            (2**63, "complex128"),
            (True, "bool"),
            (np.timedelta64(20, "ns"), "<m8[ns]"),
            (np.datetime64(20, "ns"), "<M8[ns]"),
        ],
    )
    @pytest.mark.parametrize(
        "op",
        [
            operator.add,
            operator.sub,
            operator.mul,
            operator.truediv,
            operator.mod,
            operator.pow,
        ],
        ids=lambda x: x.__name__,
    )
    def test_binop_other(self, op, value, dtype, switch_numexpr_min_elements):
        skip = {
            (operator.truediv, "bool"),
            (operator.pow, "bool"),
            (operator.add, "bool"),
            (operator.mul, "bool"),
        }

        elem = DummyElement(value, dtype)
        df = DataFrame({"A": [elem.value, elem.value]}, dtype=elem.dtype)

        invalid = {
            (operator.pow, "<M8[ns]"),
            (operator.mod, "<M8[ns]"),
            (operator.truediv, "<M8[ns]"),
            (operator.mul, "<M8[ns]"),
            (operator.add, "<M8[ns]"),
            (operator.pow, "<m8[ns]"),
            (operator.mul, "<m8[ns]"),
            (operator.sub, "bool"),
            (operator.mod, "complex128"),
        }

        ne = import_optional_dependency("numexpr", errors="ignore")
        ne_warns_on_op = ne is not None and Version(ne.__version__) < Version("2.13.1")
        if (op, dtype) in invalid:
            warn = None
            if (dtype == "<M8[ns]" and op == operator.add) or (
                dtype == "<m8[ns]" and op == operator.mul
            ):
                msg = None
            elif dtype == "complex128":
                msg = "ufunc 'remainder' not supported for the input types"
            elif op is operator.sub:
                msg = "numpy boolean subtract, the `-` operator, is "
                if (
                    dtype == "bool"
                    and expr.USE_NUMEXPR
                    and switch_numexpr_min_elements == 0
                ):
                    warn = UserWarning
            else:
                msg = (
                    f"cannot perform __{op.__name__}__ with this "
                    "index type: (DatetimeArray|TimedeltaArray)"
                )

            with pytest.raises(TypeError, match=msg):
                with tm.assert_produces_warning(warn, match="evaluating in Python"):
                    op(df, elem.value)

        elif (op, dtype) in skip:
            if op in [operator.add, operator.mul]:
                if (
                    expr.USE_NUMEXPR
                    and switch_numexpr_min_elements == 0
                    and ne_warns_on_op
                ):
                    warn = UserWarning
                else:
                    warn = None
                with tm.assert_produces_warning(warn, match="evaluating in Python"):
                    op(df, elem.value)

            else:
                msg = "operator '.*' not implemented for .* dtypes"
                with pytest.raises(NotImplementedError, match=msg):
                    op(df, elem.value)

        else:
            with tm.assert_produces_warning(None):
                result = op(df, elem.value).dtypes
                expected = op(df, value).dtypes
            tm.assert_series_equal(result, expected)

    def test_arithmetic_midx_cols_different_dtypes(self):
        # GH#49769
        midx = MultiIndex.from_arrays([Series([1, 2]), Series([3, 4])])
        midx2 = MultiIndex.from_arrays([Series([1, 2], dtype="Int8"), Series([3, 4])])
        left = DataFrame([[1, 2], [3, 4]], columns=midx)
        right = DataFrame([[1, 2], [3, 4]], columns=midx2)
        result = left - right
        expected = DataFrame([[0, 0], [0, 0]], columns=midx)
        tm.assert_frame_equal(result, expected)

    def test_arithmetic_midx_cols_different_dtypes_different_order(self):
        # GH#49769
        midx = MultiIndex.from_arrays([Series([1, 2]), Series([3, 4])])
        midx2 = MultiIndex.from_arrays([Series([2, 1], dtype="Int8"), Series([4, 3])])
        left = DataFrame([[1, 2], [3, 4]], columns=midx)
        right = DataFrame([[1, 2], [3, 4]], columns=midx2)
        result = left - right
        expected = DataFrame([[-1, 1], [-1, 1]], columns=midx)
        tm.assert_frame_equal(result, expected)

    def test_div_axis_level_multiindex_columns(self):
        # GH#64428
        x = DataFrame(
            [[1, 2, 3, 4], [5, 6, 7, 8]],
            columns=MultiIndex.from_product((["X", "Y"], ["A", "B"])),
        )
        y = DataFrame([[1, 2], [3, 4]], columns=["A", "B"])
        result = x.div(y, axis=1, level=1)
        expected = DataFrame(
            [[1 / 1, 2 / 2, 3 / 1, 4 / 2], [5 / 3, 6 / 4, 7 / 3, 8 / 4]],
            columns=MultiIndex.from_product((["X", "Y"], ["A", "B"])),
        )
        tm.assert_frame_equal(result, expected)


def test_frame_with_zero_len_series_corner_cases():
    # GH#28600
    # easy all-float case
    df = DataFrame(
        np.random.default_rng(2).standard_normal(6).reshape(3, 2), columns=["A", "B"]
    )
    ser = Series(dtype=np.float64)

    result = df + ser
    expected = DataFrame(df.values * np.nan, columns=df.columns)
    tm.assert_frame_equal(result, expected)

    with pytest.raises(ValueError, match="not aligned"):
        # Automatic alignment for comparisons deprecated GH#36795, enforced 2.0
        df == ser

    # non-float case should not raise TypeError on comparison
    df2 = DataFrame(df.values.view("M8[ns]"), columns=df.columns)
    with pytest.raises(ValueError, match="not aligned"):
        # Automatic alignment for comparisons deprecated
        df2 == ser


def test_zero_len_frame_with_series_corner_cases():
    # GH#28600
    df = DataFrame(columns=["A", "B"], dtype=np.float64)
    ser = Series([1, 2], index=["A", "B"])

    result = df + ser
    expected = df
    tm.assert_frame_equal(result, expected)


def test_frame_single_columns_object_sum_axis_1():
    # GH 13758
    data = {
        "One": Series(["A", 1.2, np.nan]),
    }
    df = DataFrame(data)
    result = df.sum(axis=1)
    expected = Series(["A", 1.2, 0])
    tm.assert_series_equal(result, expected)


# -------------------------------------------------------------------
# Unsorted
#  These arithmetic tests were previously in other files, eventually
#  should be parametrized and put into tests.arithmetic


class TestFrameArithmeticUnsorted:
    def test_frame_add_tz_mismatch_converts_to_utc(self):
        rng = pd.date_range("1/1/2011", periods=10, freq="h", tz="US/Eastern")
        df = DataFrame(
            np.random.default_rng(2).standard_normal(len(rng)), index=rng, columns=["a"]
        )

        df_moscow = df.tz_convert("Europe/Moscow")
        result = df + df_moscow
        assert result.index.tz is timezone.utc

        result = df_moscow + df
        assert result.index.tz is timezone.utc

    def test_align_frame(self):
        rng = pd.period_range("1/1/2000", "1/1/2010", freq="Y")
        ts = DataFrame(
            np.random.default_rng(2).standard_normal((len(rng), 3)), index=rng
        )

        result = ts + ts[::2]
        expected = ts + ts
        expected.iloc[1::2] = np.nan
        tm.assert_frame_equal(result, expected)

        half = ts[::2]
        result = ts + half.take(np.random.default_rng(2).permutation(len(half)))
        tm.assert_frame_equal(result, expected)

    @pytest.mark.parametrize(
        "op", [operator.add, operator.sub, operator.mul, operator.truediv]
    )
    def test_operators_none_as_na(self, op):
        df = DataFrame(
            {"col1": [2, 5.0, 123, None], "col2": [1, 2, 3, 4]}, dtype=object
        )

        # since filling converts dtypes from object, changed expected to be
        # object

        filled = df.fillna(np.nan)
        result = op(df, 3)
        expected = op(filled, 3).astype(object)
        expected[pd.isna(expected)] = np.nan
        tm.assert_frame_equal(result, expected)

        result = op(df, df)
        expected = op(filled, filled).astype(object)
        expected[pd.isna(expected)] = np.nan
        tm.assert_frame_equal(result, expected)

        result = op(df, df.fillna(7))
        tm.assert_frame_equal(result, expected)

        result = op(df.fillna(7), df)
        tm.assert_frame_equal(result, expected)

    @pytest.mark.parametrize("op,res", [("__eq__", False), ("__ne__", True)])
    # TODO: not sure what's correct here.
    @pytest.mark.filterwarnings("ignore:elementwise:FutureWarning")
    def test_logical_typeerror_with_non_valid(self, op, res, float_frame):
        # we are comparing floats vs a string
        result = getattr(float_frame, op)("foo")
        assert bool(result.all().all()) is res

    @pytest.mark.parametrize("op", ["add", "sub", "mul", "div", "truediv"])
    def test_binary_ops_align(self, op):
        # test aligning binary ops

        # GH 6681
        index = MultiIndex.from_product(
            [list("abc"), ["one", "two", "three"], [1, 2, 3]],
            names=["first", "second", "third"],
        )

        df = DataFrame(
            np.arange(27 * 3).reshape(27, 3),
            index=index,
            columns=["value1", "value2", "value3"],
        ).sort_index()

        idx = pd.IndexSlice
        opa = getattr(operator, op, None)
        if opa is None:
            return

        x = Series([1.0, 10.0, 100.0], [1, 2, 3])
        result = getattr(df, op)(x, level="third", axis=0)

        expected = pd.concat(
            [opa(df.loc[idx[:, :, i], :], v) for i, v in x.items()]
        ).sort_index()
        tm.assert_frame_equal(result, expected)

        x = Series([1.0, 10.0], ["two", "three"])
        result = getattr(df, op)(x, level="second", axis=0)

        expected = (
            pd.concat([opa(df.loc[idx[:, i], :], v) for i, v in x.items()])
            .reindex_like(df)
            .sort_index()
        )
        tm.assert_frame_equal(result, expected)

    def test_binary_ops_align_series_dataframe(self):
        # GH9463 (alignment level of dataframe with series)

        midx = MultiIndex.from_product([["A", "B"], ["a", "b"]])
        df = DataFrame(np.ones((2, 4), dtype="int64"), columns=midx)
        s = Series({"a": 1, "b": 2})

        df2 = df.copy()
        df2.columns.names = ["lvl0", "lvl1"]
        s2 = s.copy()
        s2.index.name = "lvl1"

        # different cases of integer/string level names:
        res1 = df.mul(s, axis=1, level=1)
        res2 = df.mul(s2, axis=1, level=1)
        res3 = df2.mul(s, axis=1, level=1)
        res4 = df2.mul(s2, axis=1, level=1)
        res5 = df2.mul(s, axis=1, level="lvl1")
        res6 = df2.mul(s2, axis=1, level="lvl1")

        exp = DataFrame(
            np.array([[1, 2, 1, 2], [1, 2, 1, 2]], dtype="int64"), columns=midx
        )

        for res in [res1, res2]:
            tm.assert_frame_equal(res, exp)

        exp.columns.names = ["lvl0", "lvl1"]
        for res in [res3, res4, res5, res6]:
            tm.assert_frame_equal(res, exp)

    def test_add_with_dti_mismatched_tzs(self):
        base = pd.DatetimeIndex(["2011-01-01", "2011-01-02", "2011-01-03"], tz="UTC")
        idx1 = base.tz_convert("Asia/Tokyo")[:2]
        idx2 = base.tz_convert("US/Eastern")[1:]

        df1 = DataFrame({"A": [1, 2]}, index=idx1)
        df2 = DataFrame({"A": [1, 1]}, index=idx2)
        exp = DataFrame({"A": [np.nan, 3, np.nan]}, index=base)
        tm.assert_frame_equal(df1 + df2, exp)

    def test_combineFrame(self, float_frame, mixed_float_frame, mixed_int_frame):
        frame_copy = float_frame.reindex(float_frame.index[::2])

        del frame_copy["D"]
        # adding NAs to first 5 values of column "C"
        frame_copy.loc[: frame_copy.index[4], "C"] = np.nan

        added = float_frame + frame_copy

        indexer = added["A"].dropna().index
        exp = (float_frame["A"] * 2).copy()

        tm.assert_series_equal(added["A"].dropna(), exp.loc[indexer])

        exp.loc[~exp.index.isin(indexer)] = np.nan
        tm.assert_series_equal(added["A"], exp.loc[added["A"].index])

        assert np.isnan(added["C"].reindex(frame_copy.index)[:5]).all()

        # assert(False)

        assert np.isnan(added["D"]).all()

        self_added = float_frame + float_frame
        tm.assert_index_equal(self_added.index, float_frame.index)

        added_rev = frame_copy + float_frame
        assert np.isnan(added["D"]).all()
        assert np.isnan(added_rev["D"]).all()

        # corner cases

        # empty
        plus_empty = float_frame + DataFrame()
        assert np.isnan(plus_empty.values).all()

        empty_plus = DataFrame() + float_frame
        assert np.isnan(empty_plus.values).all()

        empty_empty = DataFrame() + DataFrame()
        assert empty_empty.empty

        # out of order
        reverse = float_frame.reindex(columns=float_frame.columns[::-1])

        tm.assert_frame_equal(reverse + float_frame, float_frame * 2)

        # mix vs float64, upcast
        added = float_frame + mixed_float_frame
        _check_mixed_float(added, dtype="float64")
        added = mixed_float_frame + float_frame
        _check_mixed_float(added, dtype="float64")

        # mix vs mix
        added = mixed_float_frame + mixed_float_frame
        _check_mixed_float(added, dtype={"C": None})

        # with int
        added = float_frame + mixed_int_frame
        _check_mixed_float(added, dtype="float64")

    def test_combine_series(self, float_frame, mixed_float_frame, mixed_int_frame):
        # Series
        series = float_frame.xs(float_frame.index[0])

        added = float_frame + series

        for key, s in added.items():
            tm.assert_series_equal(s, float_frame[key] + series[key])

        larger_series = series.to_dict()
        larger_series["E"] = 1
        larger_series = Series(larger_series)
        larger_added = float_frame + larger_series

        for key, s in float_frame.items():
            tm.assert_series_equal(larger_added[key], s + series[key])
        assert "E" in larger_added
        assert np.isnan(larger_added["E"]).all()

        # no upcast needed
        added = mixed_float_frame + series
        assert np.all(added.dtypes == series.dtype)

        # vs mix (upcast) as needed
        added = mixed_float_frame + series.astype("float32")
        _check_mixed_float(added, dtype={"C": None})
        added = mixed_float_frame + series.astype("float16")
        _check_mixed_float(added, dtype={"C": None})

        # these used to raise with numexpr as we are adding an int64 to an
        #  uint64....weird vs int
        added = mixed_int_frame + (100 * series).astype("int64")
        _check_mixed_int(
            added, dtype={"A": "int64", "B": "float64", "C": "int64", "D": "int64"}
        )
        added = mixed_int_frame + (100 * series).astype("int32")
        _check_mixed_int(
            added, dtype={"A": "int32", "B": "float64", "C": "int32", "D": "int64"}
        )

    def test_combine_timeseries(self, datetime_frame):
        # TimeSeries
        ts = datetime_frame["A"]

        # 10890
        # we no longer allow auto timeseries broadcasting
        # and require explicit broadcasting
        added = datetime_frame.add(ts, axis="index")

        for key, col in datetime_frame.items():
            result = col + ts
            tm.assert_series_equal(added[key], result, check_names=False)
            assert added[key].name == key
            if col.name == ts.name:
                assert result.name == "A"
            else:
                assert result.name is None

        smaller_frame = datetime_frame[:-5]
        smaller_added = smaller_frame.add(ts, axis="index")

        tm.assert_index_equal(smaller_added.index, datetime_frame.index)

        smaller_ts = ts[:-5]
        smaller_added2 = datetime_frame.add(smaller_ts, axis="index")
        tm.assert_frame_equal(smaller_added, smaller_added2)

        # length 0, result is all-nan
        result = datetime_frame.add(ts[:0], axis="index")
        expected = DataFrame(
            np.nan, index=datetime_frame.index, columns=datetime_frame.columns
        )
        tm.assert_frame_equal(result, expected)

        # Frame is all-nan
        result = datetime_frame[:0].add(ts, axis="index")
        expected = DataFrame(
            np.nan, index=datetime_frame.index, columns=datetime_frame.columns
        )
        tm.assert_frame_equal(result, expected)

        # empty but with non-empty index
        frame = datetime_frame[:1].reindex(columns=[])
        result = frame.mul(ts, axis="index")
        assert len(result) == len(ts)

    def test_combineFunc(self, float_frame, mixed_float_frame):
        result = float_frame * 2
        tm.assert_numpy_array_equal(result.values, float_frame.values * 2)

        # vs mix
        result = mixed_float_frame * 2
        for c, s in result.items():
            tm.assert_numpy_array_equal(s.values, mixed_float_frame[c].values * 2)
        _check_mixed_float(result, dtype={"C": None})

        result = DataFrame() * 2
        assert result.index.equals(DataFrame().index)
        assert len(result.columns) == 0

    @pytest.mark.parametrize(
        "func",
        [operator.eq, operator.ne, operator.lt, operator.gt, operator.ge, operator.le],
    )
    def test_comparisons(self, simple_frame, float_frame, func):
        df1 = DataFrame(
            np.random.default_rng(2).standard_normal((30, 4)),
            columns=Index(list("ABCD"), dtype=object),
            index=pd.date_range("2000-01-01", periods=30, freq="B"),
        )
        df2 = df1.copy()

        row = simple_frame.xs("a")
        ndim_5 = np.ones((*df1.shape, 1, 1, 1))

        result = func(df1, df2)
        tm.assert_numpy_array_equal(result.values, func(df1.values, df2.values))

        msg = (
            "Unable to coerce to Series/DataFrame, "
            "dimension must be <= 2: (30, 4, 1, 1, 1)"
        )
        with pytest.raises(ValueError, match=re.escape(msg)):
            func(df1, ndim_5)

        result2 = func(simple_frame, row)
        tm.assert_numpy_array_equal(
            result2.values, func(simple_frame.values, row.values)
        )

        result3 = func(float_frame, 0)
        tm.assert_numpy_array_equal(result3.values, func(float_frame.values, 0))

        msg = (
            r"Can only compare identically-labeled \(both index and columns\) "
            "DataFrame objects"
        )
        with pytest.raises(ValueError, match=msg):
            func(simple_frame, simple_frame[:2])

    def test_strings_to_numbers_comparisons_raises(self, compare_operators_no_eq_ne):
        # GH 11565
        df = DataFrame(
            {x: {"x": "foo", "y": "bar", "z": "baz"} for x in ["a", "b", "c"]}
        )

        f = getattr(operator, compare_operators_no_eq_ne)
        msg = "|".join(
            [
                "'[<>]=?' not supported between instances of 'str' and 'int'",
                "Invalid comparison between dtype=str and int",
            ]
        )
        with pytest.raises(TypeError, match=msg):
            f(df, 0)

    def test_comparison_protected_from_errstate(self):
        missing_df = DataFrame(
            np.ones((10, 4), dtype=np.float64),
            columns=Index(list("ABCD"), dtype=object),
        )
        missing_df.loc[missing_df.index[0], "A"] = np.nan
        with np.errstate(invalid="ignore"):
            expected = missing_df.values < 0
        with np.errstate(invalid="raise"):
            result = (missing_df < 0).values
        tm.assert_numpy_array_equal(result, expected)

    def test_boolean_comparison(self):
        # GH 4576
        # boolean comparisons with a tuple/list give unexpected results
        df = DataFrame(np.arange(6).reshape((3, 2)))
        b = np.array([2, 2])
        b_r = np.atleast_2d([2, 2])
        b_c = b_r.T
        lst = [2, 2, 2]
        tup = tuple(lst)

        # gt
        expected = DataFrame([[False, False], [False, True], [True, True]])
        result = df > b
        tm.assert_frame_equal(result, expected)

        result = df.values > b
        tm.assert_numpy_array_equal(result, expected.values)

        msg1d = "Unable to coerce to Series, length must be 2: given 3"
        msg2d = "Unable to coerce to DataFrame, shape must be"
        msg2db = "operands could not be broadcast together with shapes"
        with pytest.raises(ValueError, match=msg1d):
            # wrong shape
            df > lst

        with pytest.raises(ValueError, match=msg1d):
            # wrong shape
            df > tup

        # broadcasts like ndarray (GH#23000)
        result = df > b_r
        tm.assert_frame_equal(result, expected)

        result = df.values > b_r
        tm.assert_numpy_array_equal(result, expected.values)

        with pytest.raises(ValueError, match=msg2d):
            df > b_c

        with pytest.raises(ValueError, match=msg2db):
            df.values > b_c

        # ==
        expected = DataFrame([[False, False], [True, False], [False, False]])
        result = df == b
        tm.assert_frame_equal(result, expected)

        with pytest.raises(ValueError, match=msg1d):
            df == lst

        with pytest.raises(ValueError, match=msg1d):
            df == tup

        # broadcasts like ndarray (GH#23000)
        result = df == b_r
        tm.assert_frame_equal(result, expected)

        result = df.values == b_r
        tm.assert_numpy_array_equal(result, expected.values)

        with pytest.raises(ValueError, match=msg2d):
            df == b_c

        assert df.values.shape != b_c.shape

        # with alignment
        df = DataFrame(
            np.arange(6).reshape((3, 2)), columns=list("AB"), index=list("abc")
        )
        expected.index = df.index
        expected.columns = df.columns

        with pytest.raises(ValueError, match=msg1d):
            df == lst

        with pytest.raises(ValueError, match=msg1d):
            df == tup

    def test_inplace_ops_alignment(self):
        # inplace ops / ops alignment
        # GH 8511

        columns = list("abcdefg")
        X_orig = DataFrame(
            np.arange(10 * len(columns)).reshape(-1, len(columns)),
            columns=columns,
            index=range(10),
        )
        Z = 100 * X_orig.iloc[:, 1:-1].copy()
        block1 = list("bedcf")
        subs = list("bcdef")

        # add
        X = X_orig.copy()
        result1 = (X[block1] + Z).reindex(columns=subs)

        X[block1] += Z
        result2 = X.reindex(columns=subs)

        X = X_orig.copy()
        result3 = (X[block1] + Z[block1]).reindex(columns=subs)

        X[block1] += Z[block1]
        result4 = X.reindex(columns=subs)

        tm.assert_frame_equal(result1, result2)
        tm.assert_frame_equal(result1, result3)
        tm.assert_frame_equal(result1, result4)

        # sub
        X = X_orig.copy()
        result1 = (X[block1] - Z).reindex(columns=subs)

        X[block1] -= Z
        result2 = X.reindex(columns=subs)

        X = X_orig.copy()
        result3 = (X[block1] - Z[block1]).reindex(columns=subs)

        X[block1] -= Z[block1]
        result4 = X.reindex(columns=subs)

        tm.assert_frame_equal(result1, result2)
        tm.assert_frame_equal(result1, result3)
        tm.assert_frame_equal(result1, result4)

    def test_inplace_ops_identity(self):
        # GH 5104
        # make sure that we are actually changing the object
        s_orig = Series([1, 2, 3])
        df_orig = DataFrame(
            np.random.default_rng(2).integers(0, 5, size=10).reshape(-1, 5)
        )

        # no dtype change
        s = s_orig.copy()
        s2 = s
        s += 1
        tm.assert_series_equal(s, s2)
        tm.assert_series_equal(s_orig + 1, s)
        assert s is s2
        assert s._mgr is s2._mgr

        df = df_orig.copy()
        df2 = df
        df += 1
        tm.assert_frame_equal(df, df2)
        tm.assert_frame_equal(df_orig + 1, df)
        assert df is df2
        assert df._mgr is df2._mgr

        # dtype change
        s = s_orig.copy()
        s2 = s
        s += 1.5
        tm.assert_series_equal(s, s2)
        tm.assert_series_equal(s_orig + 1.5, s)

        df = df_orig.copy()
        df2 = df
        df += 1.5
        tm.assert_frame_equal(df, df2)
        tm.assert_frame_equal(df_orig + 1.5, df)
        assert df is df2
        assert df._mgr is df2._mgr

        # mixed dtype
        arr = np.random.default_rng(2).integers(0, 10, size=5)
        df_orig = DataFrame({"A": arr.copy(), "B": "foo"})
        df = df_orig.copy()
        df2 = df
        df["A"] += 1
        expected = DataFrame({"A": arr.copy() + 1, "B": "foo"})
        tm.assert_frame_equal(df, expected)
        tm.assert_frame_equal(df2, expected)
        assert df._mgr is df2._mgr

        df = df_orig.copy()
        df2 = df
        df["A"] += 1.5
        expected = DataFrame({"A": arr.copy() + 1.5, "B": "foo"})
        tm.assert_frame_equal(df, expected)
        tm.assert_frame_equal(df2, expected)
        assert df._mgr is df2._mgr

    @pytest.mark.parametrize(
        "op",
        [
            "add",
            "and",
            pytest.param(
                "div",
                marks=pytest.mark.xfail(
                    raises=AttributeError, reason="__idiv__ not implemented"
                ),
            ),
            "floordiv",
            "mod",
            "mul",
            "or",
            "pow",
            "sub",
            "truediv",
            "xor",
        ],
    )
    def test_inplace_ops_identity2(self, op):
        df = DataFrame({"a": [1.0, 2.0, 3.0], "b": [1, 2, 3]})

        operand = 2
        if op in ("and", "or", "xor"):
            # cannot use floats for boolean ops
            df["a"] = [True, False, True]

        df_copy = df.copy()
        iop = f"__i{op}__"
        op = f"__{op}__"

        # no id change and value is correct
        getattr(df, iop)(operand)
        expected = getattr(df_copy, op)(operand)
        tm.assert_frame_equal(df, expected)
        expected = id(df)
        assert id(df) == expected

    @pytest.mark.parametrize(
        "val",
        [
            [1, 2, 3],
            (1, 2, 3),
            np.array([1, 2, 3], dtype=np.int64),
            range(1, 4),
        ],
    )
    def test_alignment_non_pandas(self, val):
        index = ["A", "B", "C"]
        columns = ["X", "Y", "Z"]
        df = DataFrame(
            np.random.default_rng(2).standard_normal((3, 3)),
            index=index,
            columns=columns,
        )

        align = DataFrame._align_for_op

        expected = DataFrame({"X": val, "Y": val, "Z": val}, index=df.index)
        tm.assert_frame_equal(align(df, val, axis=0)[1], expected)

        expected = DataFrame(
            {"X": [1, 1, 1], "Y": [2, 2, 2], "Z": [3, 3, 3]}, index=df.index
        )
        tm.assert_frame_equal(align(df, val, axis=1)[1], expected)

    @pytest.mark.parametrize("val", [[1, 2], (1, 2), np.array([1, 2]), range(1, 3)])
    def test_alignment_non_pandas_length_mismatch(self, val):
        index = ["A", "B", "C"]
        columns = ["X", "Y", "Z"]
        df = DataFrame(
            np.random.default_rng(2).standard_normal((3, 3)),
            index=index,
            columns=columns,
        )

        align = DataFrame._align_for_op
        # length mismatch
        msg = "Unable to coerce to Series, length must be 3: given 2"
        with pytest.raises(ValueError, match=msg):
            align(df, val, axis=0)

        with pytest.raises(ValueError, match=msg):
            align(df, val, axis=1)

    def test_alignment_non_pandas_index_columns(self):
        index = ["A", "B", "C"]
        columns = ["X", "Y", "Z"]
        df = DataFrame(
            np.random.default_rng(2).standard_normal((3, 3)),
            index=index,
            columns=columns,
        )

        align = DataFrame._align_for_op
        val = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
        tm.assert_frame_equal(
            align(df, val, axis=0)[1],
            DataFrame(val, index=df.index, columns=df.columns),
        )
        tm.assert_frame_equal(
            align(df, val, axis=1)[1],
            DataFrame(val, index=df.index, columns=df.columns),
        )

        # shape mismatch
        msg = "Unable to coerce to DataFrame, shape must be"
        val = np.array([[1, 2, 3], [4, 5, 6]])
        with pytest.raises(ValueError, match=msg):
            align(df, val, axis=0)

        with pytest.raises(ValueError, match=msg):
            align(df, val, axis=1)

        val = np.zeros((3, 3, 3))
        msg = re.escape(
            "Unable to coerce to Series/DataFrame, dimension must be <= 2: (3, 3, 3)"
        )
        with pytest.raises(ValueError, match=msg):
            align(df, val, axis=0)
        with pytest.raises(ValueError, match=msg):
            align(df, val, axis=1)

    def test_no_warning(self, all_arithmetic_operators):
        df = DataFrame({"A": [0.0, 0.0], "B": [0.0, None]})
        b = df["B"]
        with tm.assert_produces_warning(None):
            getattr(df, all_arithmetic_operators)(b)

    def test_dunder_methods_binary(self, all_arithmetic_operators):
        # GH#??? frame.__foo__ should only accept one argument
        df = DataFrame({"A": [0.0, 0.0], "B": [0.0, None]})
        b = df["B"]
        with pytest.raises(TypeError, match="takes 2 positional arguments"):
            getattr(df, all_arithmetic_operators)(b, 0)

    def test_align_int_fill_bug(self):
        # GH#910
        X = np.arange(10 * 10, dtype="float64").reshape(10, 10)
        Y = np.ones((10, 1), dtype=int)

        df1 = DataFrame(X)
        df1["0.X"] = Y.squeeze()

        df2 = df1.astype(float)

        result = df1 - df1.mean()
        expected = df2 - df2.mean()
        tm.assert_frame_equal(result, expected)


def test_pow_with_realignment():
    # GH#32685 pow has special semantics for operating with null values
    left = DataFrame({"A": [0, 1, 2]})
    right = DataFrame(index=[0, 1, 2])

    result = left**right
    expected = DataFrame({"A": [np.nan, 1.0, np.nan]})
    tm.assert_frame_equal(result, expected)


def test_dataframe_series_extension_dtypes():
    # https://github.com/pandas-dev/pandas/issues/34311
    df = DataFrame(
        np.random.default_rng(2).integers(0, 100, (10, 3)), columns=["a", "b", "c"]
    )
    ser = Series([1, 2, 3], index=["a", "b", "c"])

    expected = df.to_numpy("int64") + ser.to_numpy("int64").reshape(-1, 3)
    expected = DataFrame(expected, columns=df.columns, dtype="Int64")

    df_ea = df.astype("Int64")
    result = df_ea + ser
    tm.assert_frame_equal(result, expected)
    result = df_ea + ser.astype("Int64")
    tm.assert_frame_equal(result, expected)


def test_dataframe_blockwise_slicelike():
    # GH#34367
    arr = np.random.default_rng(2).integers(0, 1000, (100, 10))
    df1 = DataFrame(arr)
    # Explicit cast to float to avoid implicit cast when setting nan
    df2 = df1.copy().astype({1: "float", 3: "float", 7: "float"})
    df2.iloc[0, [1, 3, 7]] = np.nan

    # Explicit cast to float to avoid implicit cast when setting nan
    df3 = df1.copy().astype({5: "float"})
    df3.iloc[0, [5]] = np.nan

    # Explicit cast to float to avoid implicit cast when setting nan
    df4 = df1.copy().astype({2: "float", 3: "float", 4: "float"})
    df4.iloc[0, np.arange(2, 5)] = np.nan
    # Explicit cast to float to avoid implicit cast when setting nan
    df5 = df1.copy().astype({4: "float", 5: "float", 6: "float"})
    df5.iloc[0, np.arange(4, 7)] = np.nan

    for left, right in [(df1, df2), (df2, df3), (df4, df5)]:
        res = left + right

        expected = DataFrame({i: left[i] + right[i] for i in left.columns})
        tm.assert_frame_equal(res, expected)


@pytest.mark.parametrize(
    "df, col_dtype",
    [
        (DataFrame([[1.0, 2.0], [4.0, 5.0]], columns=list("ab")), "float64"),
        (
            DataFrame([[1.0, "b"], [4.0, "b"]], columns=list("ab")).astype(
                {"b": object}
            ),
            "object",
        ),
    ],
)
def test_dataframe_operation_with_non_numeric_types(df, col_dtype):
    # GH #22663
    expected = DataFrame([[0.0, np.nan], [3.0, np.nan]], columns=list("ab"))
    expected = expected.astype({"b": col_dtype})
    result = df + Series([-1.0], index=list("a"))
    tm.assert_frame_equal(result, expected)


def test_arith_reindex_with_duplicates():
    # https://github.com/pandas-dev/pandas/issues/35194
    df1 = DataFrame(data=[[0]], columns=["second"])
    df2 = DataFrame(data=[[0, 0, 0]], columns=["first", "second", "second"])
    result = df1 + df2
    expected = DataFrame([[np.nan, 0, 0]], columns=["first", "second", "second"])
    tm.assert_frame_equal(result, expected)


@pytest.mark.parametrize("to_add", [[Series([1, 1])], [Series([1, 1]), Series([1, 1])]])
def test_arith_list_of_arraylike_raise(to_add):
    # GH 36702. Raise when trying to add list of array-like to DataFrame
    df = DataFrame({"x": [1, 2], "y": [1, 2]})

    msg = f"Unable to coerce list of {type(to_add[0])} to Series/DataFrame"
    with pytest.raises(ValueError, match=msg):
        df + to_add
    with pytest.raises(ValueError, match=msg):
        to_add + df


def test_inplace_arithmetic_series_update():
    # https://github.com/pandas-dev/pandas/issues/36373
    df = DataFrame({"A": [1, 2, 3]})
    df_orig = df.copy()
    series = df["A"]
    vals = series._values

    series += 1
    assert series._values is not vals
    tm.assert_frame_equal(df, df_orig)


def test_arithmetic_multiindex_align():
    """
    Regression test for: https://github.com/pandas-dev/pandas/issues/33765
    """
    df1 = DataFrame(
        [[1]],
        index=["a"],
        columns=MultiIndex.from_product([[0], [1]], names=["a", "b"]),
    )
    df2 = DataFrame([[1]], index=["a"], columns=Index([0], name="a"))
    expected = DataFrame(
        [[0]],
        index=["a"],
        columns=MultiIndex.from_product([[0], [1]], names=["a", "b"]),
    )
    result = df1 - df2
    tm.assert_frame_equal(result, expected)


def test_arithmetic_multiindex_column_align():
    # GH#60498
    df1 = DataFrame(
        data=100,
        columns=MultiIndex.from_product(
            [["1A", "1B"], ["2A", "2B"]], names=["Lev1", "Lev2"]
        ),
        index=["C1", "C2"],
    )
    df2 = DataFrame(
        data=np.array([[0.1, 0.25], [0.2, 0.45]]),
        columns=MultiIndex.from_product([["1A", "1B"]], names=["Lev1"]),
        index=["C1", "C2"],
    )
    expected = DataFrame(
        data=np.array([[10.0, 10.0, 25.0, 25.0], [20.0, 20.0, 45.0, 45.0]]),
        columns=MultiIndex.from_product(
            [["1A", "1B"], ["2A", "2B"]], names=["Lev1", "Lev2"]
        ),
        index=["C1", "C2"],
    )
    result = df1 * df2
    tm.assert_frame_equal(result, expected)


def test_arithmetic_multiindex_column_align_with_fillvalue():
    # GH#60903
    df1 = DataFrame(
        data=[[1.0, 2.0]],
        columns=MultiIndex.from_tuples([("A", "one"), ("A", "two")]),
    )
    df2 = DataFrame(
        data=[[3.0, 4.0]],
        columns=MultiIndex.from_tuples([("B", "one"), ("B", "two")]),
    )
    expected = DataFrame(
        data=[[1.0, 2.0, 3.0, 4.0]],
        columns=MultiIndex.from_tuples(
            [("A", "one"), ("A", "two"), ("B", "one"), ("B", "two")]
        ),
    )
    result = df1.add(df2, fill_value=0)
    tm.assert_frame_equal(result, expected)


def test_bool_frame_mult_float():
    # GH 18549
    df = DataFrame(True, list("ab"), list("cd"))
    result = df * 1.0
    expected = DataFrame(np.ones((2, 2)), list("ab"), list("cd"))
    tm.assert_frame_equal(result, expected)


def test_frame_sub_nullable_int(any_int_ea_dtype):
    # GH 32822
    series1 = Series([1, 2, None], dtype=any_int_ea_dtype)
    series2 = Series([1, 2, 3], dtype=any_int_ea_dtype)
    expected = DataFrame([0, 0, None], dtype=any_int_ea_dtype)
    result = series1.to_frame() - series2.to_frame()
    tm.assert_frame_equal(result, expected)


@pytest.mark.filterwarnings(
    "ignore:Passing a BlockManager|Passing a SingleBlockManager:DeprecationWarning"
)
def test_frame_op_subclass_nonclass_constructor():
    # GH#43201 subclass._constructor is a function, not the subclass itself

    class SubclassedSeries(Series):
        @property
        def _constructor(self):
            return SubclassedSeries

        @property
        def _constructor_expanddim(self):
            return SubclassedDataFrame

    class SubclassedDataFrame(DataFrame):
        _metadata = ["my_extra_data"]

        def __init__(self, my_extra_data, *args, **kwargs) -> None:
            self.my_extra_data = my_extra_data
            super().__init__(*args, **kwargs)

        @property
        def _constructor(self):
            return functools.partial(type(self), self.my_extra_data)

        @property
        def _constructor_sliced(self):
            return SubclassedSeries

    sdf = SubclassedDataFrame("some_data", {"A": [1, 2, 3], "B": [4, 5, 6]})
    result = sdf * 2
    expected = SubclassedDataFrame("some_data", {"A": [2, 4, 6], "B": [8, 10, 12]})
    tm.assert_frame_equal(result, expected)

    result = sdf + sdf
    tm.assert_frame_equal(result, expected)


def test_enum_column_equality():
    Cols = Enum("Cols", "col1 col2")

    q1 = DataFrame({Cols.col1: [1, 2, 3]})
    q2 = DataFrame({Cols.col1: [1, 2, 3]})

    result = q1[Cols.col1] == q2[Cols.col1]
    expected = Series([True, True, True], name=Cols.col1)

    tm.assert_series_equal(result, expected)


def test_mixed_col_index_dtype(string_dtype_no_object):
    # GH 47382
    df1 = DataFrame(columns=list("abc"), data=1.0, index=[0])
    df2 = DataFrame(columns=list("abc"), data=0.0, index=[0])
    df1.columns = df2.columns.astype(string_dtype_no_object)
    result = df1 + df2
    expected = DataFrame(columns=list("abc"), data=1.0, index=[0])

    expected.columns = expected.columns.astype(string_dtype_no_object)

    tm.assert_frame_equal(result, expected)


def test_sum_mixed_empty(any_string_dtype):
    # GH 64657
    # for actual string dtype, sum gives "", for object dtype we get 0
    expected = Series(
        {"col1": "" if any_string_dtype == "string" else 0, "col2": 0}, dtype=object
    )
    empty_df = DataFrame(columns=["col1", "col2"]).astype(
        {"col1": any_string_dtype, "col2": int}
    )
    result = empty_df.sum()
    tm.assert_series_equal(result, expected)
