test_internals.py

from datetime import (
    date,
    datetime,
)
import itertools
import re

import numpy as np
import pytest

from pandas._libs.internals import BlockPlacement
from pandas.compat import IS64
import pandas.util._test_decorators as td

from pandas.core.dtypes.common import is_scalar

import pandas as pd
from pandas import (
    Categorical,
    DataFrame,
    DatetimeIndex,
    Index,
    IntervalIndex,
    Series,
    Timedelta,
    Timestamp,
    period_range,
)
import pandas._testing as tm
import pandas.core.algorithms as algos
from pandas.core.arrays import (
    DatetimeArray,
    SparseArray,
    TimedeltaArray,
)
from pandas.core.internals import (
    BlockManager,
    SingleBlockManager,
    make_block,
)
from pandas.core.internals.blocks import (
    ensure_block_shape,
    maybe_coerce_values,
    new_block,
)

# this file contains BlockManager specific tests
# TODO(ArrayManager) factor out interleave_dtype tests
pytestmark = td.skip_array_manager_invalid_test


@pytest.fixture(params=[new_block, make_block])
def block_maker(request):
    """
    Fixture to test both the internal new_block and pseudo-public make_block.
    """
    return request.param


@pytest.fixture
def mgr():
    return create_mgr(
        "a: f8; b: object; c: f8; d: object; e: f8;"
        "f: bool; g: i8; h: complex; i: datetime-1; j: datetime-2;"
        "k: M8[ns, US/Eastern]; l: M8[ns, CET];"
    )


def assert_block_equal(left, right):
    tm.assert_numpy_array_equal(left.values, right.values)
    assert left.dtype == right.dtype
    assert isinstance(left.mgr_locs, BlockPlacement)
    assert isinstance(right.mgr_locs, BlockPlacement)
    tm.assert_numpy_array_equal(left.mgr_locs.as_array, right.mgr_locs.as_array)


def get_numeric_mat(shape):
    arr = np.arange(shape[0])
    return np.lib.stride_tricks.as_strided(
        x=arr, shape=shape, strides=(arr.itemsize,) + (0,) * (len(shape) - 1)
    ).copy()


N = 10


def create_block(typestr, placement, item_shape=None, num_offset=0, maker=new_block):
    """
    Supported typestr:

        * float, f8, f4, f2
        * int, i8, i4, i2, i1
        * uint, u8, u4, u2, u1
        * complex, c16, c8
        * bool
        * object, string, O
        * datetime, dt, M8[ns], M8[ns, tz]
        * timedelta, td, m8[ns]
        * sparse (SparseArray with fill_value=0.0)
        * sparse_na (SparseArray with fill_value=np.nan)
        * category, category2

    """
    placement = BlockPlacement(placement)
    num_items = len(placement)

    if item_shape is None:
        item_shape = (N,)

    shape = (num_items,) + item_shape

    mat = get_numeric_mat(shape)

    if typestr in (
        "float",
        "f8",
        "f4",
        "f2",
        "int",
        "i8",
        "i4",
        "i2",
        "i1",
        "uint",
        "u8",
        "u4",
        "u2",
        "u1",
    ):
        values = mat.astype(typestr) + num_offset
    elif typestr in ("complex", "c16", "c8"):
        values = 1.0j * (mat.astype(typestr) + num_offset)
    elif typestr in ("object", "string", "O"):
        values = np.reshape([f"A{i:d}" for i in mat.ravel() + num_offset], shape)
    elif typestr in ("b", "bool"):
        values = np.ones(shape, dtype=np.bool_)
    elif typestr in ("datetime", "dt", "M8[ns]"):
        values = (mat * 1e9).astype("M8[ns]")
    elif typestr.startswith("M8[ns"):
        # datetime with tz
        m = re.search(r"M8\[ns,\s*(\w+\/?\w*)\]", typestr)
        assert m is not None, f"incompatible typestr -> {typestr}"
        tz = m.groups()[0]
        assert num_items == 1, "must have only 1 num items for a tz-aware"
        values = DatetimeIndex(np.arange(N) * 10**9, tz=tz)._data
        values = ensure_block_shape(values, ndim=len(shape))
    elif typestr in ("timedelta", "td", "m8[ns]"):
        values = (mat * 1).astype("m8[ns]")
    elif typestr in ("category",):
        values = Categorical([1, 1, 2, 2, 3, 3, 3, 3, 4, 4])
    elif typestr in ("category2",):
        values = Categorical(["a", "a", "a", "a", "b", "b", "c", "c", "c", "d"])
    elif typestr in ("sparse", "sparse_na"):
        if shape[-1] != 10:
            # We also are implicitly assuming this in the category cases above
            raise NotImplementedError

        assert all(s == 1 for s in shape[:-1])
        if typestr.endswith("_na"):
            fill_value = np.nan
        else:
            fill_value = 0.0
        values = SparseArray(
            [fill_value, fill_value, 1, 2, 3, fill_value, 4, 5, fill_value, 6],
            fill_value=fill_value,
        )
        arr = values.sp_values.view()
        arr += num_offset - 1
    else:
        raise ValueError(f'Unsupported typestr: "{typestr}"')

    values = maybe_coerce_values(values)
    return maker(values, placement=placement, ndim=len(shape))


def create_single_mgr(typestr, num_rows=None):
    if num_rows is None:
        num_rows = N

    return SingleBlockManager(
        create_block(typestr, placement=slice(0, num_rows), item_shape=()),
        Index(np.arange(num_rows)),
    )


def create_mgr(descr, item_shape=None):
    """
    Construct BlockManager from string description.

    String description syntax looks similar to np.matrix initializer.  It looks
    like this::

        a,b,c: f8; d,e,f: i8

    Rules are rather simple:

    * see list of supported datatypes in `create_block` method
    * components are semicolon-separated
    * each component is `NAME,NAME,NAME: DTYPE_ID`
    * whitespace around colons & semicolons are removed
    * components with same DTYPE_ID are combined into single block
    * to force multiple blocks with same dtype, use '-SUFFIX'::

        'a:f8-1; b:f8-2; c:f8-foobar'

    """
    if item_shape is None:
        item_shape = (N,)

    offset = 0
    mgr_items = []
    block_placements = {}
    for d in descr.split(";"):
        d = d.strip()
        if not len(d):
            continue
        names, blockstr = d.partition(":")[::2]
        blockstr = blockstr.strip()
        names = names.strip().split(",")

        mgr_items.extend(names)
        placement = list(np.arange(len(names)) + offset)
        try:
            block_placements[blockstr].extend(placement)
        except KeyError:
            block_placements[blockstr] = placement
        offset += len(names)

    mgr_items = Index(mgr_items)

    blocks = []
    num_offset = 0
    for blockstr, placement in block_placements.items():
        typestr = blockstr.split("-")[0]
        blocks.append(
            create_block(
                typestr, placement, item_shape=item_shape, num_offset=num_offset
            )
        )
        num_offset += len(placement)

    sblocks = sorted(blocks, key=lambda b: b.mgr_locs[0])
    return BlockManager(
        tuple(sblocks),
        [mgr_items] + [Index(np.arange(n)) for n in item_shape],
    )


@pytest.fixture
def fblock():
    return create_block("float", [0, 2, 4])


class TestBlock:
    def test_constructor(self):
        int32block = create_block("i4", [0])
        assert int32block.dtype == np.int32

    @pytest.mark.parametrize(
        "typ, data",
        [
            ["float", [0, 2, 4]],
            ["complex", [7]],
            ["object", [1, 3]],
            ["bool", [5]],
        ],
    )
    def test_pickle(self, typ, data):
        blk = create_block(typ, data)
        assert_block_equal(tm.round_trip_pickle(blk), blk)

    def test_mgr_locs(self, fblock):
        assert isinstance(fblock.mgr_locs, BlockPlacement)
        tm.assert_numpy_array_equal(
            fblock.mgr_locs.as_array, np.array([0, 2, 4], dtype=np.intp)
        )

    def test_attrs(self, fblock):
        assert fblock.shape == fblock.values.shape
        assert fblock.dtype == fblock.values.dtype
        assert len(fblock) == len(fblock.values)

    def test_copy(self, fblock):
        cop = fblock.copy()
        assert cop is not fblock
        assert_block_equal(fblock, cop)

    def test_delete(self, fblock):
        newb = fblock.copy()
        locs = newb.mgr_locs
        nb = newb.delete(0)[0]
        assert newb.mgr_locs is locs

        assert nb is not newb

        tm.assert_numpy_array_equal(
            nb.mgr_locs.as_array, np.array([2, 4], dtype=np.intp)
        )
        assert not (newb.values[0] == 1).all()
        assert (nb.values[0] == 1).all()

        newb = fblock.copy()
        locs = newb.mgr_locs
        nb = newb.delete(1)
        assert len(nb) == 2
        assert newb.mgr_locs is locs

        tm.assert_numpy_array_equal(
            nb[0].mgr_locs.as_array, np.array([0], dtype=np.intp)
        )
        tm.assert_numpy_array_equal(
            nb[1].mgr_locs.as_array, np.array([4], dtype=np.intp)
        )
        assert not (newb.values[1] == 2).all()
        assert (nb[1].values[0] == 2).all()

        newb = fblock.copy()
        nb = newb.delete(2)
        assert len(nb) == 1
        tm.assert_numpy_array_equal(
            nb[0].mgr_locs.as_array, np.array([0, 2], dtype=np.intp)
        )
        assert (nb[0].values[1] == 1).all()

        newb = fblock.copy()

        with pytest.raises(IndexError, match=None):
            newb.delete(3)

    def test_delete_datetimelike(self):
        # dont use np.delete on values, as that will coerce from DTA/TDA to ndarray
        arr = np.arange(20, dtype="i8").reshape(5, 4).view("m8[ns]")
        df = DataFrame(arr)
        blk = df._mgr.blocks[0]
        assert isinstance(blk.values, TimedeltaArray)

        nb = blk.delete(1)
        assert len(nb) == 2
        assert isinstance(nb[0].values, TimedeltaArray)
        assert isinstance(nb[1].values, TimedeltaArray)

        df = DataFrame(arr.view("M8[ns]"))
        blk = df._mgr.blocks[0]
        assert isinstance(blk.values, DatetimeArray)

        nb = blk.delete([1, 3])
        assert len(nb) == 2
        assert isinstance(nb[0].values, DatetimeArray)
        assert isinstance(nb[1].values, DatetimeArray)

    def test_split(self):
        # GH#37799
        values = np.random.default_rng(2).standard_normal((3, 4))
        blk = new_block(values, placement=BlockPlacement([3, 1, 6]), ndim=2)
        result = blk._split()

        # check that we get views, not copies
        values[:] = -9999
        assert (blk.values == -9999).all()

        assert len(result) == 3
        expected = [
            new_block(values[[0]], placement=BlockPlacement([3]), ndim=2),
            new_block(values[[1]], placement=BlockPlacement([1]), ndim=2),
            new_block(values[[2]], placement=BlockPlacement([6]), ndim=2),
        ]
        for res, exp in zip(result, expected):
            assert_block_equal(res, exp)


class TestBlockManager:
    def test_attrs(self):
        mgr = create_mgr("a,b,c: f8-1; d,e,f: f8-2")
        assert mgr.nblocks == 2
        assert len(mgr) == 6

    def test_duplicate_ref_loc_failure(self):
        tmp_mgr = create_mgr("a:bool; a: f8")

        axes, blocks = tmp_mgr.axes, tmp_mgr.blocks

        blocks[0].mgr_locs = BlockPlacement(np.array([0]))
        blocks[1].mgr_locs = BlockPlacement(np.array([0]))

        # test trying to create block manager with overlapping ref locs

        msg = "Gaps in blk ref_locs"

        with pytest.raises(AssertionError, match=msg):
            mgr = BlockManager(blocks, axes)
            mgr._rebuild_blknos_and_blklocs()

        blocks[0].mgr_locs = BlockPlacement(np.array([0]))
        blocks[1].mgr_locs = BlockPlacement(np.array([1]))
        mgr = BlockManager(blocks, axes)
        mgr.iget(1)

    def test_pickle(self, mgr):
        mgr2 = tm.round_trip_pickle(mgr)
        tm.assert_frame_equal(
            DataFrame._from_mgr(mgr, axes=mgr.axes),
            DataFrame._from_mgr(mgr2, axes=mgr2.axes),
        )

        # GH2431
        assert hasattr(mgr2, "_is_consolidated")
        assert hasattr(mgr2, "_known_consolidated")

        # reset to False on load
        assert not mgr2._is_consolidated
        assert not mgr2._known_consolidated

    @pytest.mark.parametrize("mgr_string", ["a,a,a:f8", "a: f8; a: i8"])
    def test_non_unique_pickle(self, mgr_string):
        mgr = create_mgr(mgr_string)
        mgr2 = tm.round_trip_pickle(mgr)
        tm.assert_frame_equal(
            DataFrame._from_mgr(mgr, axes=mgr.axes),
            DataFrame._from_mgr(mgr2, axes=mgr2.axes),
        )

    def test_categorical_block_pickle(self):
        mgr = create_mgr("a: category")
        mgr2 = tm.round_trip_pickle(mgr)
        tm.assert_frame_equal(
            DataFrame._from_mgr(mgr, axes=mgr.axes),
            DataFrame._from_mgr(mgr2, axes=mgr2.axes),
        )

        smgr = create_single_mgr("category")
        smgr2 = tm.round_trip_pickle(smgr)
        tm.assert_series_equal(
            Series()._constructor_from_mgr(smgr, axes=smgr.axes),
            Series()._constructor_from_mgr(smgr2, axes=smgr2.axes),
        )

    def test_iget(self):
        cols = Index(list("abc"))
        values = np.random.default_rng(2).random((3, 3))
        block = new_block(
            values=values.copy(),
            placement=BlockPlacement(np.arange(3, dtype=np.intp)),
            ndim=values.ndim,
        )
        mgr = BlockManager(blocks=(block,), axes=[cols, Index(np.arange(3))])

        tm.assert_almost_equal(mgr.iget(0).internal_values(), values[0])
        tm.assert_almost_equal(mgr.iget(1).internal_values(), values[1])
        tm.assert_almost_equal(mgr.iget(2).internal_values(), values[2])

    def test_set(self):
        mgr = create_mgr("a,b,c: int", item_shape=(3,))

        mgr.insert(len(mgr.items), "d", np.array(["foo"] * 3))
        mgr.iset(1, np.array(["bar"] * 3))
        tm.assert_numpy_array_equal(mgr.iget(0).internal_values(), np.array([0] * 3))
        tm.assert_numpy_array_equal(
            mgr.iget(1).internal_values(), np.array(["bar"] * 3, dtype=np.object_)
        )
        tm.assert_numpy_array_equal(mgr.iget(2).internal_values(), np.array([2] * 3))
        tm.assert_numpy_array_equal(
            mgr.iget(3).internal_values(), np.array(["foo"] * 3, dtype=np.object_)
        )

    def test_set_change_dtype(self, mgr):
        mgr.insert(len(mgr.items), "baz", np.zeros(N, dtype=bool))

        mgr.iset(mgr.items.get_loc("baz"), np.repeat("foo", N))
        idx = mgr.items.get_loc("baz")
        assert mgr.iget(idx).dtype == np.object_

        mgr2 = mgr.consolidate()
        mgr2.iset(mgr2.items.get_loc("baz"), np.repeat("foo", N))
        idx = mgr2.items.get_loc("baz")
        assert mgr2.iget(idx).dtype == np.object_

        mgr2.insert(
            len(mgr2.items),
            "quux",
            np.random.default_rng(2).standard_normal(N).astype(int),
        )
        idx = mgr2.items.get_loc("quux")
        assert mgr2.iget(idx).dtype == np.dtype(int)

        mgr2.iset(
            mgr2.items.get_loc("quux"), np.random.default_rng(2).standard_normal(N)
        )
        assert mgr2.iget(idx).dtype == np.float64

    def test_copy(self, mgr):
        cp = mgr.copy(deep=False)
        for blk, cp_blk in zip(mgr.blocks, cp.blocks):
            # view assertion
            tm.assert_equal(cp_blk.values, blk.values)
            if isinstance(blk.values, np.ndarray):
                assert cp_blk.values.base is blk.values.base
            else:
                # DatetimeTZBlock has DatetimeIndex values
                assert cp_blk.values._ndarray.base is blk.values._ndarray.base

        # copy(deep=True) consolidates, so the block-wise assertions will
        #  fail is mgr is not consolidated
        mgr._consolidate_inplace()
        cp = mgr.copy(deep=True)
        for blk, cp_blk in zip(mgr.blocks, cp.blocks):
            bvals = blk.values
            cpvals = cp_blk.values

            tm.assert_equal(cpvals, bvals)

            if isinstance(cpvals, np.ndarray):
                lbase = cpvals.base
                rbase = bvals.base
            else:
                lbase = cpvals._ndarray.base
                rbase = bvals._ndarray.base

            # copy assertion we either have a None for a base or in case of
            # some blocks it is an array (e.g. datetimetz), but was copied
            if isinstance(cpvals, DatetimeArray):
                assert (lbase is None and rbase is None) or (lbase is not rbase)
            elif not isinstance(cpvals, np.ndarray):
                assert lbase is not rbase
            else:
                assert lbase is None and rbase is None

    def test_sparse(self):
        mgr = create_mgr("a: sparse-1; b: sparse-2")
        assert mgr.as_array().dtype == np.float64

    def test_sparse_mixed(self):
        mgr = create_mgr("a: sparse-1; b: sparse-2; c: f8")
        assert len(mgr.blocks) == 3
        assert isinstance(mgr, BlockManager)

    @pytest.mark.parametrize(
        "mgr_string, dtype",
        [("c: f4; d: f2", np.float32), ("c: f4; d: f2; e: f8", np.float64)],
    )
    def test_as_array_float(self, mgr_string, dtype):
        mgr = create_mgr(mgr_string)
        assert mgr.as_array().dtype == dtype

    @pytest.mark.parametrize(
        "mgr_string, dtype",
        [
            ("a: bool-1; b: bool-2", np.bool_),
            ("a: i8-1; b: i8-2; c: i4; d: i2; e: u1", np.int64),
            ("c: i4; d: i2; e: u1", np.int32),
        ],
    )
    def test_as_array_int_bool(self, mgr_string, dtype):
        mgr = create_mgr(mgr_string)
        assert mgr.as_array().dtype == dtype

    def test_as_array_datetime(self):
        mgr = create_mgr("h: datetime-1; g: datetime-2")
        assert mgr.as_array().dtype == "M8[ns]"

    def test_as_array_datetime_tz(self):
        mgr = create_mgr("h: M8[ns, US/Eastern]; g: M8[ns, CET]")
        assert mgr.iget(0).dtype == "datetime64[ns, US/Eastern]"
        assert mgr.iget(1).dtype == "datetime64[ns, CET]"
        assert mgr.as_array().dtype == "object"

    @pytest.mark.parametrize("t", ["float16", "float32", "float64", "int32", "int64"])
    def test_astype(self, t):
        # coerce all
        mgr = create_mgr("c: f4; d: f2; e: f8")

        t = np.dtype(t)
        tmgr = mgr.astype(t)
        assert tmgr.iget(0).dtype.type == t
        assert tmgr.iget(1).dtype.type == t
        assert tmgr.iget(2).dtype.type == t

        # mixed
        mgr = create_mgr("a,b: object; c: bool; d: datetime; e: f4; f: f2; g: f8")

        t = np.dtype(t)
        tmgr = mgr.astype(t, errors="ignore")
        assert tmgr.iget(2).dtype.type == t
        assert tmgr.iget(4).dtype.type == t
        assert tmgr.iget(5).dtype.type == t
        assert tmgr.iget(6).dtype.type == t

        assert tmgr.iget(0).dtype.type == np.object_
        assert tmgr.iget(1).dtype.type == np.object_
        if t != np.int64:
            assert tmgr.iget(3).dtype.type == np.datetime64
        else:
            assert tmgr.iget(3).dtype.type == t

    def test_convert(self, using_infer_string):
        def _compare(old_mgr, new_mgr):
            """compare the blocks, numeric compare ==, object don't"""
            old_blocks = set(old_mgr.blocks)
            new_blocks = set(new_mgr.blocks)
            assert len(old_blocks) == len(new_blocks)

            # compare non-numeric
            for b in old_blocks:
                found = False
                for nb in new_blocks:
                    if (b.values == nb.values).all():
                        found = True
                        break
                assert found

            for b in new_blocks:
                found = False
                for ob in old_blocks:
                    if (b.values == ob.values).all():
                        found = True
                        break
                assert found

        # noops
        mgr = create_mgr("f: i8; g: f8")
        new_mgr = mgr.convert(copy=True)
        _compare(mgr, new_mgr)

        # convert
        mgr = create_mgr("a,b,foo: object; f: i8; g: f8")
        mgr.iset(0, np.array(["1"] * N, dtype=np.object_))
        mgr.iset(1, np.array(["2."] * N, dtype=np.object_))
        mgr.iset(2, np.array(["foo."] * N, dtype=np.object_))
        new_mgr = mgr.convert(copy=True)
        dtype = "string[pyarrow_numpy]" if using_infer_string else np.object_
        assert new_mgr.iget(0).dtype == dtype
        assert new_mgr.iget(1).dtype == dtype
        assert new_mgr.iget(2).dtype == dtype
        assert new_mgr.iget(3).dtype == np.int64
        assert new_mgr.iget(4).dtype == np.float64

        mgr = create_mgr(
            "a,b,foo: object; f: i4; bool: bool; dt: datetime; i: i8; g: f8; h: f2"
        )
        mgr.iset(0, np.array(["1"] * N, dtype=np.object_))
        mgr.iset(1, np.array(["2."] * N, dtype=np.object_))
        mgr.iset(2, np.array(["foo."] * N, dtype=np.object_))
        new_mgr = mgr.convert(copy=True)
        assert new_mgr.iget(0).dtype == dtype
        assert new_mgr.iget(1).dtype == dtype
        assert new_mgr.iget(2).dtype == dtype
        assert new_mgr.iget(3).dtype == np.int32
        assert new_mgr.iget(4).dtype == np.bool_
        assert new_mgr.iget(5).dtype.type, np.datetime64
        assert new_mgr.iget(6).dtype == np.int64
        assert new_mgr.iget(7).dtype == np.float64
        assert new_mgr.iget(8).dtype == np.float16

    def test_interleave(self):
        # self
        for dtype in ["f8", "i8", "object", "bool", "complex", "M8[ns]", "m8[ns]"]:
            mgr = create_mgr(f"a: {dtype}")
            assert mgr.as_array().dtype == dtype
            mgr = create_mgr(f"a: {dtype}; b: {dtype}")
            assert mgr.as_array().dtype == dtype

    @pytest.mark.parametrize(
        "mgr_string, dtype",
        [
            ("a: category", "i8"),
            ("a: category; b: category", "i8"),
            ("a: category; b: category2", "object"),
            ("a: category2", "object"),
            ("a: category2; b: category2", "object"),
            ("a: f8", "f8"),
            ("a: f8; b: i8", "f8"),
            ("a: f4; b: i8", "f8"),
            ("a: f4; b: i8; d: object", "object"),
            ("a: bool; b: i8", "object"),
            ("a: complex", "complex"),
            ("a: f8; b: category", "object"),
            ("a: M8[ns]; b: category", "object"),
            ("a: M8[ns]; b: bool", "object"),
            ("a: M8[ns]; b: i8", "object"),
            ("a: m8[ns]; b: bool", "object"),
            ("a: m8[ns]; b: i8", "object"),
            ("a: M8[ns]; b: m8[ns]", "object"),
        ],
    )
    def test_interleave_dtype(self, mgr_string, dtype):
        # will be converted according the actual dtype of the underlying
        mgr = create_mgr("a: category")
        assert mgr.as_array().dtype == "i8"
        mgr = create_mgr("a: category; b: category2")
        assert mgr.as_array().dtype == "object"
        mgr = create_mgr("a: category2")
        assert mgr.as_array().dtype == "object"

        # combinations
        mgr = create_mgr("a: f8")
        assert mgr.as_array().dtype == "f8"
        mgr = create_mgr("a: f8; b: i8")
        assert mgr.as_array().dtype == "f8"
        mgr = create_mgr("a: f4; b: i8")
        assert mgr.as_array().dtype == "f8"
        mgr = create_mgr("a: f4; b: i8; d: object")
        assert mgr.as_array().dtype == "object"
        mgr = create_mgr("a: bool; b: i8")
        assert mgr.as_array().dtype == "object"
        mgr = create_mgr("a: complex")
        assert mgr.as_array().dtype == "complex"
        mgr = create_mgr("a: f8; b: category")
        assert mgr.as_array().dtype == "f8"
        mgr = create_mgr("a: M8[ns]; b: category")
        assert mgr.as_array().dtype == "object"
        mgr = create_mgr("a: M8[ns]; b: bool")
        assert mgr.as_array().dtype == "object"
        mgr = create_mgr("a: M8[ns]; b: i8")
        assert mgr.as_array().dtype == "object"
        mgr = create_mgr("a: m8[ns]; b: bool")
        assert mgr.as_array().dtype == "object"
        mgr = create_mgr("a: m8[ns]; b: i8")
        assert mgr.as_array().dtype == "object"
        mgr = create_mgr("a: M8[ns]; b: m8[ns]")
        assert mgr.as_array().dtype == "object"

    def test_consolidate_ordering_issues(self, mgr):
        mgr.iset(mgr.items.get_loc("f"), np.random.default_rng(2).standard_normal(N))
        mgr.iset(mgr.items.get_loc("d"), np.random.default_rng(2).standard_normal(N))
        mgr.iset(mgr.items.get_loc("b"), np.random.default_rng(2).standard_normal(N))
        mgr.iset(mgr.items.get_loc("g"), np.random.default_rng(2).standard_normal(N))
        mgr.iset(mgr.items.get_loc("h"), np.random.default_rng(2).standard_normal(N))

        # we have datetime/tz blocks in mgr
        cons = mgr.consolidate()
        assert cons.nblocks == 4
        cons = mgr.consolidate().get_numeric_data()
        assert cons.nblocks == 1
        assert isinstance(cons.blocks[0].mgr_locs, BlockPlacement)
        tm.assert_numpy_array_equal(
            cons.blocks[0].mgr_locs.as_array, np.arange(len(cons.items), dtype=np.intp)
        )

    def test_reindex_items(self):
        # mgr is not consolidated, f8 & f8-2 blocks
        mgr = create_mgr("a: f8; b: i8; c: f8; d: i8; e: f8; f: bool; g: f8-2")

        reindexed = mgr.reindex_axis(["g", "c", "a", "d"], axis=0)
        # reindex_axis does not consolidate_inplace, as that risks failing to
        #  invalidate _item_cache
        assert not reindexed.is_consolidated()

        tm.assert_index_equal(reindexed.items, Index(["g", "c", "a", "d"]))
        tm.assert_almost_equal(
            mgr.iget(6).internal_values(), reindexed.iget(0).internal_values()
        )
        tm.assert_almost_equal(
            mgr.iget(2).internal_values(), reindexed.iget(1).internal_values()
        )
        tm.assert_almost_equal(
            mgr.iget(0).internal_values(), reindexed.iget(2).internal_values()
        )
        tm.assert_almost_equal(
            mgr.iget(3).internal_values(), reindexed.iget(3).internal_values()
        )

    def test_get_numeric_data(self, using_copy_on_write):
        mgr = create_mgr(
            "int: int; float: float; complex: complex;"
            "str: object; bool: bool; obj: object; dt: datetime",
            item_shape=(3,),
        )
        mgr.iset(5, np.array([1, 2, 3], dtype=np.object_))

        numeric = mgr.get_numeric_data()
        tm.assert_index_equal(numeric.items, Index(["int", "float", "complex", "bool"]))
        tm.assert_almost_equal(
            mgr.iget(mgr.items.get_loc("float")).internal_values(),
            numeric.iget(numeric.items.get_loc("float")).internal_values(),
        )

        # Check sharing
        numeric.iset(
            numeric.items.get_loc("float"),
            np.array([100.0, 200.0, 300.0]),
            inplace=True,
        )
        if using_copy_on_write:
            tm.assert_almost_equal(
                mgr.iget(mgr.items.get_loc("float")).internal_values(),
                np.array([1.0, 1.0, 1.0]),
            )
        else:
            tm.assert_almost_equal(
                mgr.iget(mgr.items.get_loc("float")).internal_values(),
                np.array([100.0, 200.0, 300.0]),
            )

        numeric2 = mgr.get_numeric_data(copy=True)
        tm.assert_index_equal(numeric.items, Index(["int", "float", "complex", "bool"]))
        numeric2.iset(
            numeric2.items.get_loc("float"),
            np.array([1000.0, 2000.0, 3000.0]),
            inplace=True,
        )
        if using_copy_on_write:
            tm.assert_almost_equal(
                mgr.iget(mgr.items.get_loc("float")).internal_values(),
                np.array([1.0, 1.0, 1.0]),
            )
        else:
            tm.assert_almost_equal(
                mgr.iget(mgr.items.get_loc("float")).internal_values(),
                np.array([100.0, 200.0, 300.0]),
            )

    def test_get_bool_data(self, using_copy_on_write):
        mgr = create_mgr(
            "int: int; float: float; complex: complex;"
            "str: object; bool: bool; obj: object; dt: datetime",
            item_shape=(3,),
        )
        mgr.iset(6, np.array([True, False, True], dtype=np.object_))

        bools = mgr.get_bool_data()
        tm.assert_index_equal(bools.items, Index(["bool"]))
        tm.assert_almost_equal(
            mgr.iget(mgr.items.get_loc("bool")).internal_values(),
            bools.iget(bools.items.get_loc("bool")).internal_values(),
        )

        bools.iset(0, np.array([True, False, True]), inplace=True)
        if using_copy_on_write:
            tm.assert_numpy_array_equal(
                mgr.iget(mgr.items.get_loc("bool")).internal_values(),
                np.array([True, True, True]),
            )
        else:
            tm.assert_numpy_array_equal(
                mgr.iget(mgr.items.get_loc("bool")).internal_values(),
                np.array([True, False, True]),
            )

        # Check sharing
        bools2 = mgr.get_bool_data(copy=True)
        bools2.iset(0, np.array([False, True, False]))
        if using_copy_on_write:
            tm.assert_numpy_array_equal(
                mgr.iget(mgr.items.get_loc("bool")).internal_values(),
                np.array([True, True, True]),
            )
        else:
            tm.assert_numpy_array_equal(
                mgr.iget(mgr.items.get_loc("bool")).internal_values(),
                np.array([True, False, True]),
            )

    def test_unicode_repr_doesnt_raise(self):
        repr(create_mgr("b,\u05d0: object"))

    @pytest.mark.parametrize(
        "mgr_string", ["a,b,c: i8-1; d,e,f: i8-2", "a,a,a: i8-1; b,b,b: i8-2"]
    )
    def test_equals(self, mgr_string):
        # unique items
        bm1 = create_mgr(mgr_string)
        bm2 = BlockManager(bm1.blocks[::-1], bm1.axes)
        assert bm1.equals(bm2)

    @pytest.mark.parametrize(
        "mgr_string",
        [
            "a:i8;b:f8",  # basic case
            "a:i8;b:f8;c:c8;d:b",  # many types
            "a:i8;e:dt;f:td;g:string",  # more types
            "a:i8;b:category;c:category2",  # categories
            "c:sparse;d:sparse_na;b:f8",  # sparse
        ],
    )
    def test_equals_block_order_different_dtypes(self, mgr_string):
        # GH 9330
        bm = create_mgr(mgr_string)
        block_perms = itertools.permutations(bm.blocks)
        for bm_perm in block_perms:
            bm_this = BlockManager(tuple(bm_perm), bm.axes)
            assert bm.equals(bm_this)
            assert bm_this.equals(bm)

    def test_single_mgr_ctor(self):
        mgr = create_single_mgr("f8", num_rows=5)
        assert mgr.external_values().tolist() == [0.0, 1.0, 2.0, 3.0, 4.0]

    @pytest.mark.parametrize("value", [1, "True", [1, 2, 3], 5.0])
    def test_validate_bool_args(self, value):
        bm1 = create_mgr("a,b,c: i8-1; d,e,f: i8-2")

        msg = (
            'For argument "inplace" expected type bool, '
            f"received type {type(value).__name__}."
        )
        with pytest.raises(ValueError, match=msg):
            bm1.replace_list([1], [2], inplace=value)

    def test_iset_split_block(self):
        bm = create_mgr("a,b,c: i8; d: f8")
        bm._iset_split_block(0, np.array([0]))
        tm.assert_numpy_array_equal(
            bm.blklocs, np.array([0, 0, 1, 0], dtype="int64" if IS64 else "int32")
        )
        # First indexer currently does not have a block associated with it in case
        tm.assert_numpy_array_equal(
            bm.blknos, np.array([0, 0, 0, 1], dtype="int64" if IS64 else "int32")
        )
        assert len(bm.blocks) == 2

    def test_iset_split_block_values(self):
        bm = create_mgr("a,b,c: i8; d: f8")
        bm._iset_split_block(0, np.array([0]), np.array([list(range(10))]))
        tm.assert_numpy_array_equal(
            bm.blklocs, np.array([0, 0, 1, 0], dtype="int64" if IS64 else "int32")
        )
        # First indexer currently does not have a block associated with it in case
        tm.assert_numpy_array_equal(
            bm.blknos, np.array([0, 2, 2, 1], dtype="int64" if IS64 else "int32")
        )
        assert len(bm.blocks) == 3


def _as_array(mgr):
    if mgr.ndim == 1:
        return mgr.external_values()
    return mgr.as_array().T


class TestIndexing:
    # Nosetests-style data-driven tests.
    #
    # This test applies different indexing routines to block managers and
    # compares the outcome to the result of same operations on np.ndarray.
    #
    # NOTE: sparse (SparseBlock with fill_value != np.nan) fail a lot of tests
    #       and are disabled.

    MANAGERS = [
        create_single_mgr("f8", N),
        create_single_mgr("i8", N),
        # 2-dim
        create_mgr("a,b,c,d,e,f: f8", item_shape=(N,)),
        create_mgr("a,b,c,d,e,f: i8", item_shape=(N,)),
        create_mgr("a,b: f8; c,d: i8; e,f: string", item_shape=(N,)),
        create_mgr("a,b: f8; c,d: i8; e,f: f8", item_shape=(N,)),
    ]

    @pytest.mark.parametrize("mgr", MANAGERS)
    def test_get_slice(self, mgr):
        def assert_slice_ok(mgr, axis, slobj):
            mat = _as_array(mgr)

            # we maybe using an ndarray to test slicing and
            # might not be the full length of the axis
            if isinstance(slobj, np.ndarray):
                ax = mgr.axes[axis]
                if len(ax) and len(slobj) and len(slobj) != len(ax):
                    slobj = np.concatenate(
                        [slobj, np.zeros(len(ax) - len(slobj), dtype=bool)]
                    )

            if isinstance(slobj, slice):
                sliced = mgr.get_slice(slobj, axis=axis)
            elif (
                mgr.ndim == 1
                and axis == 0
                and isinstance(slobj, np.ndarray)
                and slobj.dtype == bool
            ):
                sliced = mgr.get_rows_with_mask(slobj)
            else:
                # BlockManager doesn't support non-slice, SingleBlockManager
                #  doesn't support axis > 0
                raise TypeError(slobj)

            mat_slobj = (slice(None),) * axis + (slobj,)
            tm.assert_numpy_array_equal(
                mat[mat_slobj], _as_array(sliced), check_dtype=False
            )
            tm.assert_index_equal(mgr.axes[axis][slobj], sliced.axes[axis])

        assert mgr.ndim <= 2, mgr.ndim
        for ax in range(mgr.ndim):
            # slice
            assert_slice_ok(mgr, ax, slice(None))
            assert_slice_ok(mgr, ax, slice(3))
            assert_slice_ok(mgr, ax, slice(100))
            assert_slice_ok(mgr, ax, slice(1, 4))
            assert_slice_ok(mgr, ax, slice(3, 0, -2))

            if mgr.ndim < 2:
                # 2D only support slice objects

                # boolean mask
                assert_slice_ok(mgr, ax, np.ones(mgr.shape[ax], dtype=np.bool_))
                assert_slice_ok(mgr, ax, np.zeros(mgr.shape[ax], dtype=np.bool_))

                if mgr.shape[ax] >= 3:
                    assert_slice_ok(mgr, ax, np.arange(mgr.shape[ax]) % 3 == 0)
                    assert_slice_ok(
                        mgr, ax, np.array([True, True, False], dtype=np.bool_)
                    )

    @pytest.mark.parametrize("mgr", MANAGERS)
    def test_take(self, mgr):
        def assert_take_ok(mgr, axis, indexer):
            mat = _as_array(mgr)
            taken = mgr.take(indexer, axis)
            tm.assert_numpy_array_equal(
                np.take(mat, indexer, axis), _as_array(taken), check_dtype=False
            )
            tm.assert_index_equal(mgr.axes[axis].take(indexer), taken.axes[axis])

        for ax in range(mgr.ndim):
            # take/fancy indexer
            assert_take_ok(mgr, ax, indexer=np.array([], dtype=np.intp))
            assert_take_ok(mgr, ax, indexer=np.array([0, 0, 0], dtype=np.intp))
            assert_take_ok(
                mgr, ax, indexer=np.array(list(range(mgr.shape[ax])), dtype=np.intp)
            )

            if mgr.shape[ax] >= 3:
                assert_take_ok(mgr, ax, indexer=np.array([0, 1, 2], dtype=np.intp))
                assert_take_ok(mgr, ax, indexer=np.array([-1, -2, -3], dtype=np.intp))

    @pytest.mark.parametrize("mgr", MANAGERS)
    @pytest.mark.parametrize("fill_value", [None, np.nan, 100.0])
    def test_reindex_axis(self, fill_value, mgr):
        def assert_reindex_axis_is_ok(mgr, axis, new_labels, fill_value):
            mat = _as_array(mgr)
            indexer = mgr.axes[axis].get_indexer_for(new_labels)

            reindexed = mgr.reindex_axis(new_labels, axis, fill_value=fill_value)
            tm.assert_numpy_array_equal(
                algos.take_nd(mat, indexer, axis, fill_value=fill_value),
                _as_array(reindexed),
                check_dtype=False,
            )
            tm.assert_index_equal(reindexed.axes[axis], new_labels)

        for ax in range(mgr.ndim):
            assert_reindex_axis_is_ok(mgr, ax, Index([]), fill_value)
            assert_reindex_axis_is_ok(mgr, ax, mgr.axes[ax], fill_value)
            assert_reindex_axis_is_ok(mgr, ax, mgr.axes[ax][[0, 0, 0]], fill_value)
            assert_reindex_axis_is_ok(mgr, ax, Index(["foo", "bar", "baz"]), fill_value)
            assert_reindex_axis_is_ok(
                mgr, ax, Index(["foo", mgr.axes[ax][0], "baz"]), fill_value
            )

            if mgr.shape[ax] >= 3:
                assert_reindex_axis_is_ok(mgr, ax, mgr.axes[ax][:-3], fill_value)
                assert_reindex_axis_is_ok(mgr, ax, mgr.axes[ax][-3::-1], fill_value)
                assert_reindex_axis_is_ok(
                    mgr, ax, mgr.axes[ax][[0, 1, 2, 0, 1, 2]], fill_value
                )

    @pytest.mark.parametrize("mgr", MANAGERS)
    @pytest.mark.parametrize("fill_value", [None, np.nan, 100.0])
    def test_reindex_indexer(self, fill_value, mgr):
        def assert_reindex_indexer_is_ok(mgr, axis, new_labels, indexer, fill_value):
            mat = _as_array(mgr)
            reindexed_mat = algos.take_nd(mat, indexer, axis, fill_value=fill_value)
            reindexed = mgr.reindex_indexer(
                new_labels, indexer, axis, fill_value=fill_value
            )
            tm.assert_numpy_array_equal(
                reindexed_mat, _as_array(reindexed), check_dtype=False
            )
            tm.assert_index_equal(reindexed.axes[axis], new_labels)

        for ax in range(mgr.ndim):
            assert_reindex_indexer_is_ok(
                mgr, ax, Index([]), np.array([], dtype=np.intp), fill_value
            )
            assert_reindex_indexer_is_ok(
                mgr, ax, mgr.axes[ax], np.arange(mgr.shape[ax]), fill_value
            )
            assert_reindex_indexer_is_ok(
                mgr,
                ax,
                Index(["foo"] * mgr.shape[ax]),
                np.arange(mgr.shape[ax]),
                fill_value,
            )
            assert_reindex_indexer_is_ok(
                mgr, ax, mgr.axes[ax][::-1], np.arange(mgr.shape[ax]), fill_value
            )
            assert_reindex_indexer_is_ok(
                mgr, ax, mgr.axes[ax], np.arange(mgr.shape[ax])[::-1], fill_value
            )
            assert_reindex_indexer_is_ok(
                mgr, ax, Index(["foo", "bar", "baz"]), np.array([0, 0, 0]), fill_value
            )
            assert_reindex_indexer_is_ok(
                mgr, ax, Index(["foo", "bar", "baz"]), np.array([-1, 0, -1]), fill_value
            )
            assert_reindex_indexer_is_ok(
                mgr,
                ax,
                Index(["foo", mgr.axes[ax][0], "baz"]),
                np.array([-1, -1, -1]),
                fill_value,
            )

            if mgr.shape[ax] >= 3:
                assert_reindex_indexer_is_ok(
                    mgr,
                    ax,
                    Index(["foo", "bar", "baz"]),
                    np.array([0, 1, 2]),
                    fill_value,
                )


class TestBlockPlacement:
    @pytest.mark.parametrize(
        "slc, expected",
        [
            (slice(0, 4), 4),
            (slice(0, 4, 2), 2),
            (slice(0, 3, 2), 2),
            (slice(0, 1, 2), 1),
            (slice(1, 0, -1), 1),
        ],
    )
    def test_slice_len(self, slc, expected):
        assert len(BlockPlacement(slc)) == expected

    @pytest.mark.parametrize("slc", [slice(1, 1, 0), slice(1, 2, 0)])
    def test_zero_step_raises(self, slc):
        msg = "slice step cannot be zero"
        with pytest.raises(ValueError, match=msg):
            BlockPlacement(slc)

    def test_slice_canonize_negative_stop(self):
        # GH#37524 negative stop is OK with negative step and positive start
        slc = slice(3, -1, -2)

        bp = BlockPlacement(slc)
        assert bp.indexer == slice(3, None, -2)

    @pytest.mark.parametrize(
        "slc",
        [
            slice(None, None),
            slice(10, None),
            slice(None, None, -1),
            slice(None, 10, -1),
            # These are "unbounded" because negative index will
            #  change depending on container shape.
            slice(-1, None),
            slice(None, -1),
            slice(-1, -1),
            slice(-1, None, -1),
            slice(None, -1, -1),
            slice(-1, -1, -1),
        ],
    )
    def test_unbounded_slice_raises(self, slc):
        msg = "unbounded slice"
        with pytest.raises(ValueError, match=msg):
            BlockPlacement(slc)

    @pytest.mark.parametrize(
        "slc",
        [
            slice(0, 0),
            slice(100, 0),
            slice(100, 100),
            slice(100, 100, -1),
            slice(0, 100, -1),
        ],
    )
    def test_not_slice_like_slices(self, slc):
        assert not BlockPlacement(slc).is_slice_like

    @pytest.mark.parametrize(
        "arr, slc",
        [
            ([0], slice(0, 1, 1)),
            ([100], slice(100, 101, 1)),
            ([0, 1, 2], slice(0, 3, 1)),
            ([0, 5, 10], slice(0, 15, 5)),
            ([0, 100], slice(0, 200, 100)),
            ([2, 1], slice(2, 0, -1)),
        ],
    )
    def test_array_to_slice_conversion(self, arr, slc):
        assert BlockPlacement(arr).as_slice == slc

    @pytest.mark.parametrize(
        "arr",
        [
            [],
            [-1],
            [-1, -2, -3],
            [-10],
            [-1],
            [-1, 0, 1, 2],
            [-2, 0, 2, 4],
            [1, 0, -1],
            [1, 1, 1],
        ],
    )
    def test_not_slice_like_arrays(self, arr):
        assert not BlockPlacement(arr).is_slice_like

    @pytest.mark.parametrize(
        "slc, expected",
        [(slice(0, 3), [0, 1, 2]), (slice(0, 0), []), (slice(3, 0), [])],
    )
    def test_slice_iter(self, slc, expected):
        assert list(BlockPlacement(slc)) == expected

    @pytest.mark.parametrize(
        "slc, arr",
        [
            (slice(0, 3), [0, 1, 2]),
            (slice(0, 0), []),
            (slice(3, 0), []),
            (slice(3, 0, -1), [3, 2, 1]),
        ],
    )
    def test_slice_to_array_conversion(self, slc, arr):
        tm.assert_numpy_array_equal(
            BlockPlacement(slc).as_array, np.asarray(arr, dtype=np.intp)
        )

    def test_blockplacement_add(self):
        bpl = BlockPlacement(slice(0, 5))
        assert bpl.add(1).as_slice == slice(1, 6, 1)
        assert bpl.add(np.arange(5)).as_slice == slice(0, 10, 2)
        assert list(bpl.add(np.arange(5, 0, -1))) == [5, 5, 5, 5, 5]

    @pytest.mark.parametrize(
        "val, inc, expected",
        [
            (slice(0, 0), 0, []),
            (slice(1, 4), 0, [1, 2, 3]),
            (slice(3, 0, -1), 0, [3, 2, 1]),
            ([1, 2, 4], 0, [1, 2, 4]),
            (slice(0, 0), 10, []),
            (slice(1, 4), 10, [11, 12, 13]),
            (slice(3, 0, -1), 10, [13, 12, 11]),
            ([1, 2, 4], 10, [11, 12, 14]),
            (slice(0, 0), -1, []),
            (slice(1, 4), -1, [0, 1, 2]),
            ([1, 2, 4], -1, [0, 1, 3]),
        ],
    )
    def test_blockplacement_add_int(self, val, inc, expected):
        assert list(BlockPlacement(val).add(inc)) == expected

    @pytest.mark.parametrize("val", [slice(1, 4), [1, 2, 4]])
    def test_blockplacement_add_int_raises(self, val):
        msg = "iadd causes length change"
        with pytest.raises(ValueError, match=msg):
            BlockPlacement(val).add(-10)


class TestCanHoldElement:
    @pytest.fixture(
        params=[
            lambda x: x,
            lambda x: x.to_series(),
            lambda x: x._data,
            lambda x: list(x),
            lambda x: x.astype(object),
            lambda x: np.asarray(x),
            lambda x: x[0],
            lambda x: x[:0],
        ]
    )
    def element(self, request):
        """
        Functions that take an Index and return an element that should have
        blk._can_hold_element(element) for a Block with this index's dtype.
        """
        return request.param

    def test_datetime_block_can_hold_element(self):
        block = create_block("datetime", [0])

        assert block._can_hold_element([])

        # We will check that block._can_hold_element iff arr.__setitem__ works
        arr = pd.array(block.values.ravel())

        # coerce None
        assert block._can_hold_element(None)
        arr[0] = None
        assert arr[0] is pd.NaT

        # coerce different types of datetime objects
        vals = [np.datetime64("2010-10-10"), datetime(2010, 10, 10)]
        for val in vals:
            assert block._can_hold_element(val)
            arr[0] = val

        val = date(2010, 10, 10)
        assert not block._can_hold_element(val)

        msg = (
            "value should be a 'Timestamp', 'NaT', "
            "or array of those. Got 'date' instead."
        )
        with pytest.raises(TypeError, match=msg):
            arr[0] = val

    @pytest.mark.parametrize("dtype", [np.int64, np.uint64, np.float64])
    def test_interval_can_hold_element_emptylist(self, dtype, element):
        arr = np.array([1, 3, 4], dtype=dtype)
        ii = IntervalIndex.from_breaks(arr)
        blk = new_block(ii._data, BlockPlacement([1]), ndim=2)

        assert blk._can_hold_element([])
        # TODO: check this holds for all blocks

    @pytest.mark.parametrize("dtype", [np.int64, np.uint64, np.float64])
    def test_interval_can_hold_element(self, dtype, element):
        arr = np.array([1, 3, 4, 9], dtype=dtype)
        ii = IntervalIndex.from_breaks(arr)
        blk = new_block(ii._data, BlockPlacement([1]), ndim=2)

        elem = element(ii)
        self.check_series_setitem(elem, ii, True)
        assert blk._can_hold_element(elem)

        # Careful: to get the expected Series-inplace behavior we need
        # `elem` to not have the same length as `arr`
        ii2 = IntervalIndex.from_breaks(arr[:-1], closed="neither")
        elem = element(ii2)
        with tm.assert_produces_warning(FutureWarning):
            self.check_series_setitem(elem, ii, False)
        assert not blk._can_hold_element(elem)

        ii3 = IntervalIndex.from_breaks([Timestamp(1), Timestamp(3), Timestamp(4)])
        elem = element(ii3)
        with tm.assert_produces_warning(FutureWarning):
            self.check_series_setitem(elem, ii, False)
        assert not blk._can_hold_element(elem)

        ii4 = IntervalIndex.from_breaks([Timedelta(1), Timedelta(3), Timedelta(4)])
        elem = element(ii4)
        with tm.assert_produces_warning(FutureWarning):
            self.check_series_setitem(elem, ii, False)
        assert not blk._can_hold_element(elem)

    def test_period_can_hold_element_emptylist(self):
        pi = period_range("2016", periods=3, freq="Y")
        blk = new_block(pi._data.reshape(1, 3), BlockPlacement([1]), ndim=2)

        assert blk._can_hold_element([])

    def test_period_can_hold_element(self, element):
        pi = period_range("2016", periods=3, freq="Y")

        elem = element(pi)
        self.check_series_setitem(elem, pi, True)

        # Careful: to get the expected Series-inplace behavior we need
        # `elem` to not have the same length as `arr`
        pi2 = pi.asfreq("D")[:-1]
        elem = element(pi2)
        with tm.assert_produces_warning(FutureWarning):
            self.check_series_setitem(elem, pi, False)

        dti = pi.to_timestamp("s")[:-1]
        elem = element(dti)
        with tm.assert_produces_warning(FutureWarning):
            self.check_series_setitem(elem, pi, False)

    def check_can_hold_element(self, obj, elem, inplace: bool):
        blk = obj._mgr.blocks[0]
        if inplace:
            assert blk._can_hold_element(elem)
        else:
            assert not blk._can_hold_element(elem)

    def check_series_setitem(self, elem, index: Index, inplace: bool):
        arr = index._data.copy()
        ser = Series(arr, copy=False)

        self.check_can_hold_element(ser, elem, inplace)

        if is_scalar(elem):
            ser[0] = elem
        else:
            ser[: len(elem)] = elem

        if inplace:
            assert ser.array is arr  # i.e. setting was done inplace
        else:
            assert ser.dtype == object


class TestShouldStore:
    def test_should_store_categorical(self):
        cat = Categorical(["A", "B", "C"])
        df = DataFrame(cat)
        blk = df._mgr.blocks[0]

        # matching dtype
        assert blk.should_store(cat)
        assert blk.should_store(cat[:-1])

        # different dtype
        assert not blk.should_store(cat.as_ordered())

        # ndarray instead of Categorical
        assert not blk.should_store(np.asarray(cat))


def test_validate_ndim():
    values = np.array([1.0, 2.0])
    placement = BlockPlacement(slice(2))
    msg = r"Wrong number of dimensions. values.ndim != ndim \[1 != 2\]"
    depr_msg = "make_block is deprecated"

    with pytest.raises(ValueError, match=msg):
        with tm.assert_produces_warning(DeprecationWarning, match=depr_msg):
            make_block(values, placement, ndim=2)


def test_block_shape():
    idx = Index([0, 1, 2, 3, 4])
    a = Series([1, 2, 3]).reindex(idx)
    b = Series(Categorical([1, 2, 3])).reindex(idx)

    assert a._mgr.blocks[0].mgr_locs.indexer == b._mgr.blocks[0].mgr_locs.indexer


def test_make_block_no_pandas_array(block_maker):
    # https://github.com/pandas-dev/pandas/pull/24866
    arr = pd.arrays.NumpyExtensionArray(np.array([1, 2]))

    warn = None if block_maker is not make_block else DeprecationWarning
    msg = "make_block is deprecated and will be removed in a future version"

    # NumpyExtensionArray, no dtype
    with tm.assert_produces_warning(warn, match=msg):
        result = block_maker(arr, BlockPlacement(slice(len(arr))), ndim=arr.ndim)
    assert result.dtype.kind in ["i", "u"]

    if block_maker is make_block:
        # new_block requires caller to unwrap NumpyExtensionArray
        assert result.is_extension is False

        # NumpyExtensionArray, NumpyEADtype
        with tm.assert_produces_warning(warn, match=msg):
            result = block_maker(arr, slice(len(arr)), dtype=arr.dtype, ndim=arr.ndim)
        assert result.dtype.kind in ["i", "u"]
        assert result.is_extension is False

        # new_block no longer taked dtype keyword
        # ndarray, NumpyEADtype
        with tm.assert_produces_warning(warn, match=msg):
            result = block_maker(
                arr.to_numpy(), slice(len(arr)), dtype=arr.dtype, ndim=arr.ndim
            )
        assert result.dtype.kind in ["i", "u"]
        assert result.is_extension is False