test_constructors.py

import array
from collections import (
    OrderedDict,
    abc,
    defaultdict,
    namedtuple,
)
from dataclasses import make_dataclass
from datetime import (
    date,
    datetime,
    timedelta,
)
import functools
import random
import re
from typing import Iterator
import warnings

import numpy as np
from numpy import ma
from numpy.ma import mrecords
import pytest
import pytz

from pandas.errors import IntCastingNaNError
import pandas.util._test_decorators as td

from pandas.core.dtypes.common import is_integer_dtype
from pandas.core.dtypes.dtypes import (
    DatetimeTZDtype,
    IntervalDtype,
    PandasDtype,
    PeriodDtype,
)

import pandas as pd
from pandas import (
    Categorical,
    CategoricalIndex,
    DataFrame,
    DatetimeIndex,
    Index,
    Interval,
    MultiIndex,
    Period,
    RangeIndex,
    Series,
    Timedelta,
    Timestamp,
    cut,
    date_range,
    isna,
)
import pandas._testing as tm
from pandas.arrays import (
    DatetimeArray,
    IntervalArray,
    PeriodArray,
    SparseArray,
    TimedeltaArray,
)

MIXED_FLOAT_DTYPES = ["float16", "float32", "float64"]
MIXED_INT_DTYPES = [
    "uint8",
    "uint16",
    "uint32",
    "uint64",
    "int8",
    "int16",
    "int32",
    "int64",
]


class TestDataFrameConstructors:
    def test_constructor_from_ndarray_with_str_dtype(self):
        # If we don't ravel/reshape around ensure_str_array, we end up
        #  with an array of strings each of which is e.g. "[0 1 2]"
        arr = np.arange(12).reshape(4, 3)
        df = DataFrame(arr, dtype=str)
        expected = DataFrame(arr.astype(str))
        tm.assert_frame_equal(df, expected)

    def test_constructor_from_2d_datetimearray(self, using_array_manager):
        dti = date_range("2016-01-01", periods=6, tz="US/Pacific")
        dta = dti._data.reshape(3, 2)

        df = DataFrame(dta)
        expected = DataFrame({0: dta[:, 0], 1: dta[:, 1]})
        tm.assert_frame_equal(df, expected)
        if not using_array_manager:
            # GH#44724 big performance hit if we de-consolidate
            assert len(df._mgr.blocks) == 1

    def test_constructor_dict_with_tzaware_scalar(self):
        # GH#42505
        dt = Timestamp("2019-11-03 01:00:00-0700").tz_convert("America/Los_Angeles")

        df = DataFrame({"dt": dt}, index=[0])
        expected = DataFrame({"dt": [dt]})
        tm.assert_frame_equal(df, expected)

        # Non-homogeneous
        df = DataFrame({"dt": dt, "value": [1]})
        expected = DataFrame({"dt": [dt], "value": [1]})
        tm.assert_frame_equal(df, expected)

    def test_construct_ndarray_with_nas_and_int_dtype(self):
        # GH#26919 match Series by not casting np.nan to meaningless int
        arr = np.array([[1, np.nan], [2, 3]])
        msg = r"Cannot convert non-finite values \(NA or inf\) to integer"
        with pytest.raises(IntCastingNaNError, match=msg):
            DataFrame(arr, dtype="i8")

        # check this matches Series behavior
        with pytest.raises(IntCastingNaNError, match=msg):
            Series(arr[0], dtype="i8", name=0)

    def test_construct_from_list_of_datetimes(self):
        df = DataFrame([datetime.now(), datetime.now()])
        assert df[0].dtype == np.dtype("M8[ns]")

    def test_constructor_from_tzaware_datetimeindex(self):
        # don't cast a DatetimeIndex WITH a tz, leave as object
        # GH#6032
        naive = DatetimeIndex(["2013-1-1 13:00", "2013-1-2 14:00"], name="B")
        idx = naive.tz_localize("US/Pacific")

        expected = Series(np.array(idx.tolist(), dtype="object"), name="B")
        assert expected.dtype == idx.dtype

        # convert index to series
        result = Series(idx)
        tm.assert_series_equal(result, expected)

    def test_array_of_dt64_nat_with_td64dtype_raises(self, frame_or_series):
        # GH#39462
        nat = np.datetime64("NaT", "ns")
        arr = np.array([nat], dtype=object)
        if frame_or_series is DataFrame:
            arr = arr.reshape(1, 1)

        msg = "Invalid type for timedelta scalar: <class 'numpy.datetime64'>"
        with pytest.raises(TypeError, match=msg):
            frame_or_series(arr, dtype="m8[ns]")

    @pytest.mark.parametrize("kind", ["m", "M"])
    def test_datetimelike_values_with_object_dtype(self, kind, frame_or_series):
        # with dtype=object, we should cast dt64 values to Timestamps, not pydatetimes
        if kind == "M":
            dtype = "M8[ns]"
            scalar_type = Timestamp
        else:
            dtype = "m8[ns]"
            scalar_type = Timedelta

        arr = np.arange(6, dtype="i8").view(dtype).reshape(3, 2)
        if frame_or_series is Series:
            arr = arr[:, 0]

        obj = frame_or_series(arr, dtype=object)
        assert obj._mgr.arrays[0].dtype == object
        assert isinstance(obj._mgr.arrays[0].ravel()[0], scalar_type)

        # go through a different path in internals.construction
        obj = frame_or_series(frame_or_series(arr), dtype=object)
        assert obj._mgr.arrays[0].dtype == object
        assert isinstance(obj._mgr.arrays[0].ravel()[0], scalar_type)

        obj = frame_or_series(frame_or_series(arr), dtype=PandasDtype(object))
        assert obj._mgr.arrays[0].dtype == object
        assert isinstance(obj._mgr.arrays[0].ravel()[0], scalar_type)

        if frame_or_series is DataFrame:
            # other paths through internals.construction
            sers = [Series(x) for x in arr]
            obj = frame_or_series(sers, dtype=object)
            assert obj._mgr.arrays[0].dtype == object
            assert isinstance(obj._mgr.arrays[0].ravel()[0], scalar_type)

    def test_series_with_name_not_matching_column(self):
        # GH#9232
        x = Series(range(5), name=1)
        y = Series(range(5), name=0)

        result = DataFrame(x, columns=[0])
        expected = DataFrame([], columns=[0])
        tm.assert_frame_equal(result, expected)

        result = DataFrame(y, columns=[1])
        expected = DataFrame([], columns=[1])
        tm.assert_frame_equal(result, expected)

    @pytest.mark.parametrize(
        "constructor",
        [
            lambda: DataFrame(),
            lambda: DataFrame(None),
            lambda: DataFrame(()),
            lambda: DataFrame([]),
            lambda: DataFrame(_ for _ in []),
            lambda: DataFrame(range(0)),
            lambda: DataFrame(data=None),
            lambda: DataFrame(data=()),
            lambda: DataFrame(data=[]),
            lambda: DataFrame(data=(_ for _ in [])),
            lambda: DataFrame(data=range(0)),
        ],
    )
    def test_empty_constructor(self, constructor):
        expected = DataFrame()
        result = constructor()
        assert len(result.index) == 0
        assert len(result.columns) == 0
        tm.assert_frame_equal(result, expected)

    @pytest.mark.parametrize(
        "constructor",
        [
            lambda: DataFrame({}),
            lambda: DataFrame(data={}),
        ],
    )
    def test_empty_constructor_object_index(self, constructor):
        expected = DataFrame(columns=Index([]))
        result = constructor()
        assert len(result.index) == 0
        assert len(result.columns) == 0
        tm.assert_frame_equal(result, expected, check_index_type=True)

    @pytest.mark.parametrize(
        "emptylike,expected_index,expected_columns",
        [
            ([[]], RangeIndex(1), RangeIndex(0)),
            ([[], []], RangeIndex(2), RangeIndex(0)),
            ([(_ for _ in [])], RangeIndex(1), RangeIndex(0)),
        ],
    )
    def test_emptylike_constructor(self, emptylike, expected_index, expected_columns):
        expected = DataFrame(index=expected_index, columns=expected_columns)
        result = DataFrame(emptylike)
        tm.assert_frame_equal(result, expected)

    def test_constructor_mixed(self, float_string_frame):
        index, data = tm.getMixedTypeDict()

        # TODO(wesm), incomplete test?
        indexed_frame = DataFrame(data, index=index)  # noqa
        unindexed_frame = DataFrame(data)  # noqa

        assert float_string_frame["foo"].dtype == np.object_

    def test_constructor_cast_failure(self):
        # as of 2.0, we raise if we can't respect "dtype", previously we
        #  silently ignored
        msg = "could not convert string to float"
        with pytest.raises(ValueError, match=msg):
            DataFrame({"a": ["a", "b", "c"]}, dtype=np.float64)

        # GH 3010, constructing with odd arrays
        df = DataFrame(np.ones((4, 2)))

        # this is ok
        df["foo"] = np.ones((4, 2)).tolist()

        # this is not ok
        msg = "Expected a 1D array, got an array with shape \\(4, 2\\)"
        with pytest.raises(ValueError, match=msg):
            df["test"] = np.ones((4, 2))

        # this is ok
        df["foo2"] = np.ones((4, 2)).tolist()

    def test_constructor_dtype_copy(self):
        orig_df = DataFrame({"col1": [1.0], "col2": [2.0], "col3": [3.0]})

        new_df = DataFrame(orig_df, dtype=float, copy=True)

        new_df["col1"] = 200.0
        assert orig_df["col1"][0] == 1.0

    def test_constructor_dtype_nocast_view_dataframe(self, using_copy_on_write):
        df = DataFrame([[1, 2]])
        should_be_view = DataFrame(df, dtype=df[0].dtype)
        if using_copy_on_write:
            # TODO(CoW) doesn't mutate original
            should_be_view.iloc[0, 0] = 99
            # assert df.values[0, 0] == 1
            assert df.values[0, 0] == 99
        else:
            should_be_view[0][0] = 99
            assert df.values[0, 0] == 99

    def test_constructor_dtype_nocast_view_2d_array(
        self, using_array_manager, using_copy_on_write
    ):
        df = DataFrame([[1, 2], [3, 4]], dtype="int64")
        if not using_array_manager and not using_copy_on_write:
            should_be_view = DataFrame(df.values, dtype=df[0].dtype)
            should_be_view[0][0] = 97
            assert df.values[0, 0] == 97
        else:
            # INFO(ArrayManager) DataFrame(ndarray) doesn't necessarily preserve
            # a view on the array to ensure contiguous 1D arrays
            df2 = DataFrame(df.values, dtype=df[0].dtype)
            assert df2._mgr.arrays[0].flags.c_contiguous

    @td.skip_array_manager_invalid_test
    def test_1d_object_array_does_not_copy(self):
        # https://github.com/pandas-dev/pandas/issues/39272
        arr = np.array(["a", "b"], dtype="object")
        df = DataFrame(arr)
        assert np.shares_memory(df.values, arr)

    @td.skip_array_manager_invalid_test
    def test_2d_object_array_does_not_copy(self):
        # https://github.com/pandas-dev/pandas/issues/39272
        arr = np.array([["a", "b"], ["c", "d"]], dtype="object")
        df = DataFrame(arr)
        assert np.shares_memory(df.values, arr)

    def test_constructor_dtype_list_data(self):
        df = DataFrame([[1, "2"], [None, "a"]], dtype=object)
        assert df.loc[1, 0] is None
        assert df.loc[0, 1] == "2"

    def test_constructor_list_of_2d_raises(self):
        # https://github.com/pandas-dev/pandas/issues/32289
        a = DataFrame()
        b = np.empty((0, 0))
        with pytest.raises(ValueError, match=r"shape=\(1, 0, 0\)"):
            DataFrame([a])

        with pytest.raises(ValueError, match=r"shape=\(1, 0, 0\)"):
            DataFrame([b])

        a = DataFrame({"A": [1, 2]})
        with pytest.raises(ValueError, match=r"shape=\(2, 2, 1\)"):
            DataFrame([a, a])

    @pytest.mark.parametrize(
        "typ, ad",
        [
            # mixed floating and integer coexist in the same frame
            ["float", {}],
            # add lots of types
            ["float", {"A": 1, "B": "foo", "C": "bar"}],
            # GH 622
            ["int", {}],
        ],
    )
    def test_constructor_mixed_dtypes(self, typ, ad):
        if typ == "int":
            dtypes = MIXED_INT_DTYPES
            arrays = [np.array(np.random.rand(10), dtype=d) for d in dtypes]
        elif typ == "float":
            dtypes = MIXED_FLOAT_DTYPES
            arrays = [np.array(np.random.randint(10, size=10), dtype=d) for d in dtypes]

        for d, a in zip(dtypes, arrays):
            assert a.dtype == d
        ad.update(dict(zip(dtypes, arrays)))
        df = DataFrame(ad)

        dtypes = MIXED_FLOAT_DTYPES + MIXED_INT_DTYPES
        for d in dtypes:
            if d in df:
                assert df.dtypes[d] == d

    def test_constructor_complex_dtypes(self):
        # GH10952
        a = np.random.rand(10).astype(np.complex64)
        b = np.random.rand(10).astype(np.complex128)

        df = DataFrame({"a": a, "b": b})
        assert a.dtype == df.a.dtype
        assert b.dtype == df.b.dtype

    def test_constructor_dtype_str_na_values(self, string_dtype):
        # https://github.com/pandas-dev/pandas/issues/21083
        df = DataFrame({"A": ["x", None]}, dtype=string_dtype)
        result = df.isna()
        expected = DataFrame({"A": [False, True]})
        tm.assert_frame_equal(result, expected)
        assert df.iloc[1, 0] is None

        df = DataFrame({"A": ["x", np.nan]}, dtype=string_dtype)
        assert np.isnan(df.iloc[1, 0])

    def test_constructor_rec(self, float_frame):
        rec = float_frame.to_records(index=False)
        rec.dtype.names = list(rec.dtype.names)[::-1]

        index = float_frame.index

        df = DataFrame(rec)
        tm.assert_index_equal(df.columns, Index(rec.dtype.names))

        df2 = DataFrame(rec, index=index)
        tm.assert_index_equal(df2.columns, Index(rec.dtype.names))
        tm.assert_index_equal(df2.index, index)

        # case with columns != the ones we would infer from the data
        rng = np.arange(len(rec))[::-1]
        df3 = DataFrame(rec, index=rng, columns=["C", "B"])
        expected = DataFrame(rec, index=rng).reindex(columns=["C", "B"])
        tm.assert_frame_equal(df3, expected)

    def test_constructor_bool(self):
        df = DataFrame({0: np.ones(10, dtype=bool), 1: np.zeros(10, dtype=bool)})
        assert df.values.dtype == np.bool_

    def test_constructor_overflow_int64(self):
        # see gh-14881
        values = np.array([2**64 - i for i in range(1, 10)], dtype=np.uint64)

        result = DataFrame({"a": values})
        assert result["a"].dtype == np.uint64

        # see gh-2355
        data_scores = [
            (6311132704823138710, 273),
            (2685045978526272070, 23),
            (8921811264899370420, 45),
            (17019687244989530680, 270),
            (9930107427299601010, 273),
        ]
        dtype = [("uid", "u8"), ("score", "u8")]
        data = np.zeros((len(data_scores),), dtype=dtype)
        data[:] = data_scores
        df_crawls = DataFrame(data)
        assert df_crawls["uid"].dtype == np.uint64

    @pytest.mark.parametrize(
        "values",
        [
            np.array([2**64], dtype=object),
            np.array([2**65]),
            [2**64 + 1],
            np.array([-(2**63) - 4], dtype=object),
            np.array([-(2**64) - 1]),
            [-(2**65) - 2],
        ],
    )
    def test_constructor_int_overflow(self, values):
        # see gh-18584
        value = values[0]
        result = DataFrame(values)

        assert result[0].dtype == object
        assert result[0][0] == value

    @pytest.mark.parametrize(
        "values",
        [
            np.array([1], dtype=np.uint16),
            np.array([1], dtype=np.uint32),
            np.array([1], dtype=np.uint64),
            [np.uint16(1)],
            [np.uint32(1)],
            [np.uint64(1)],
        ],
    )
    def test_constructor_numpy_uints(self, values):
        # GH#47294
        value = values[0]
        result = DataFrame(values)

        assert result[0].dtype == value.dtype
        assert result[0][0] == value

    def test_constructor_ordereddict(self):
        nitems = 100
        nums = list(range(nitems))
        random.shuffle(nums)
        expected = [f"A{i:d}" for i in nums]
        df = DataFrame(OrderedDict(zip(expected, [[0]] * nitems)))
        assert expected == list(df.columns)

    def test_constructor_dict(self):
        datetime_series = tm.makeTimeSeries(nper=30)
        # test expects index shifted by 5
        datetime_series_short = tm.makeTimeSeries(nper=30)[5:]

        frame = DataFrame({"col1": datetime_series, "col2": datetime_series_short})

        # col2 is padded with NaN
        assert len(datetime_series) == 30
        assert len(datetime_series_short) == 25

        tm.assert_series_equal(frame["col1"], datetime_series.rename("col1"))

        exp = Series(
            np.concatenate([[np.nan] * 5, datetime_series_short.values]),
            index=datetime_series.index,
            name="col2",
        )
        tm.assert_series_equal(exp, frame["col2"])

        frame = DataFrame(
            {"col1": datetime_series, "col2": datetime_series_short},
            columns=["col2", "col3", "col4"],
        )

        assert len(frame) == len(datetime_series_short)
        assert "col1" not in frame
        assert isna(frame["col3"]).all()

        # Corner cases
        assert len(DataFrame()) == 0

        # mix dict and array, wrong size - no spec for which error should raise
        # first
        msg = "Mixing dicts with non-Series may lead to ambiguous ordering."
        with pytest.raises(ValueError, match=msg):
            DataFrame({"A": {"a": "a", "b": "b"}, "B": ["a", "b", "c"]})

    def test_constructor_dict_length1(self):
        # Length-one dict micro-optimization
        frame = DataFrame({"A": {"1": 1, "2": 2}})
        tm.assert_index_equal(frame.index, Index(["1", "2"]))

    def test_constructor_dict_with_index(self):
        # empty dict plus index
        idx = Index([0, 1, 2])
        frame = DataFrame({}, index=idx)
        assert frame.index is idx

    def test_constructor_dict_with_index_and_columns(self):
        # empty dict with index and columns
        idx = Index([0, 1, 2])
        frame = DataFrame({}, index=idx, columns=idx)
        assert frame.index is idx
        assert frame.columns is idx
        assert len(frame._series) == 3

    def test_constructor_dict_of_empty_lists(self):
        # with dict of empty list and Series
        frame = DataFrame({"A": [], "B": []}, columns=["A", "B"])
        tm.assert_index_equal(frame.index, RangeIndex(0), exact=True)

    def test_constructor_dict_with_none(self):
        # GH 14381
        # Dict with None value
        frame_none = DataFrame({"a": None}, index=[0])
        frame_none_list = DataFrame({"a": [None]}, index=[0])
        assert frame_none._get_value(0, "a") is None
        assert frame_none_list._get_value(0, "a") is None
        tm.assert_frame_equal(frame_none, frame_none_list)

    def test_constructor_dict_errors(self):
        # GH10856
        # dict with scalar values should raise error, even if columns passed
        msg = "If using all scalar values, you must pass an index"
        with pytest.raises(ValueError, match=msg):
            DataFrame({"a": 0.7})

        with pytest.raises(ValueError, match=msg):
            DataFrame({"a": 0.7}, columns=["a"])

    @pytest.mark.parametrize("scalar", [2, np.nan, None, "D"])
    def test_constructor_invalid_items_unused(self, scalar):
        # No error if invalid (scalar) value is in fact not used:
        result = DataFrame({"a": scalar}, columns=["b"])
        expected = DataFrame(columns=["b"])
        tm.assert_frame_equal(result, expected)

    @pytest.mark.parametrize("value", [2, np.nan, None, float("nan")])
    def test_constructor_dict_nan_key(self, value):
        # GH 18455
        cols = [1, value, 3]
        idx = ["a", value]
        values = [[0, 3], [1, 4], [2, 5]]
        data = {cols[c]: Series(values[c], index=idx) for c in range(3)}
        result = DataFrame(data).sort_values(1).sort_values("a", axis=1)
        expected = DataFrame(
            np.arange(6, dtype="int64").reshape(2, 3), index=idx, columns=cols
        )
        tm.assert_frame_equal(result, expected)

        result = DataFrame(data, index=idx).sort_values("a", axis=1)
        tm.assert_frame_equal(result, expected)

        result = DataFrame(data, index=idx, columns=cols)
        tm.assert_frame_equal(result, expected)

    @pytest.mark.parametrize("value", [np.nan, None, float("nan")])
    def test_constructor_dict_nan_tuple_key(self, value):
        # GH 18455
        cols = Index([(11, 21), (value, 22), (13, value)])
        idx = Index([("a", value), (value, 2)])
        values = [[0, 3], [1, 4], [2, 5]]
        data = {cols[c]: Series(values[c], index=idx) for c in range(3)}
        result = DataFrame(data).sort_values((11, 21)).sort_values(("a", value), axis=1)
        expected = DataFrame(
            np.arange(6, dtype="int64").reshape(2, 3), index=idx, columns=cols
        )
        tm.assert_frame_equal(result, expected)

        result = DataFrame(data, index=idx).sort_values(("a", value), axis=1)
        tm.assert_frame_equal(result, expected)

        result = DataFrame(data, index=idx, columns=cols)
        tm.assert_frame_equal(result, expected)

    def test_constructor_dict_order_insertion(self):
        datetime_series = tm.makeTimeSeries(nper=30)
        datetime_series_short = tm.makeTimeSeries(nper=25)

        # GH19018
        # initialization ordering: by insertion order if python>= 3.6
        d = {"b": datetime_series_short, "a": datetime_series}
        frame = DataFrame(data=d)
        expected = DataFrame(data=d, columns=list("ba"))
        tm.assert_frame_equal(frame, expected)

    def test_constructor_dict_nan_key_and_columns(self):
        # GH 16894
        result = DataFrame({np.nan: [1, 2], 2: [2, 3]}, columns=[np.nan, 2])
        expected = DataFrame([[1, 2], [2, 3]], columns=[np.nan, 2])
        tm.assert_frame_equal(result, expected)

    def test_constructor_multi_index(self):
        # GH 4078
        # construction error with mi and all-nan frame
        tuples = [(2, 3), (3, 3), (3, 3)]
        mi = MultiIndex.from_tuples(tuples)
        df = DataFrame(index=mi, columns=mi)
        assert isna(df).values.ravel().all()

        tuples = [(3, 3), (2, 3), (3, 3)]
        mi = MultiIndex.from_tuples(tuples)
        df = DataFrame(index=mi, columns=mi)
        assert isna(df).values.ravel().all()

    def test_constructor_2d_index(self):
        # GH 25416
        # handling of 2d index in construction
        df = DataFrame([[1]], columns=[[1]], index=[1, 2])
        expected = DataFrame(
            [1, 1],
            index=Index([1, 2], dtype="int64"),
            columns=MultiIndex(levels=[[1]], codes=[[0]]),
        )
        tm.assert_frame_equal(df, expected)

        df = DataFrame([[1]], columns=[[1]], index=[[1, 2]])
        expected = DataFrame(
            [1, 1],
            index=MultiIndex(levels=[[1, 2]], codes=[[0, 1]]),
            columns=MultiIndex(levels=[[1]], codes=[[0]]),
        )
        tm.assert_frame_equal(df, expected)

    def test_constructor_error_msgs(self):
        msg = "Empty data passed with indices specified."
        # passing an empty array with columns specified.
        with pytest.raises(ValueError, match=msg):
            DataFrame(np.empty(0), columns=list("abc"))

        msg = "Mixing dicts with non-Series may lead to ambiguous ordering."
        # mix dict and array, wrong size
        with pytest.raises(ValueError, match=msg):
            DataFrame({"A": {"a": "a", "b": "b"}, "B": ["a", "b", "c"]})

        # wrong size ndarray, GH 3105
        msg = r"Shape of passed values is \(4, 3\), indices imply \(3, 3\)"
        with pytest.raises(ValueError, match=msg):
            DataFrame(
                np.arange(12).reshape((4, 3)),
                columns=["foo", "bar", "baz"],
                index=date_range("2000-01-01", periods=3),
            )

        arr = np.array([[4, 5, 6]])
        msg = r"Shape of passed values is \(1, 3\), indices imply \(1, 4\)"
        with pytest.raises(ValueError, match=msg):
            DataFrame(index=[0], columns=range(0, 4), data=arr)

        arr = np.array([4, 5, 6])
        msg = r"Shape of passed values is \(3, 1\), indices imply \(1, 4\)"
        with pytest.raises(ValueError, match=msg):
            DataFrame(index=[0], columns=range(0, 4), data=arr)

        # higher dim raise exception
        with pytest.raises(ValueError, match="Must pass 2-d input"):
            DataFrame(np.zeros((3, 3, 3)), columns=["A", "B", "C"], index=[1])

        # wrong size axis labels
        msg = r"Shape of passed values is \(2, 3\), indices imply \(1, 3\)"
        with pytest.raises(ValueError, match=msg):
            DataFrame(np.random.rand(2, 3), columns=["A", "B", "C"], index=[1])

        msg = r"Shape of passed values is \(2, 3\), indices imply \(2, 2\)"
        with pytest.raises(ValueError, match=msg):
            DataFrame(np.random.rand(2, 3), columns=["A", "B"], index=[1, 2])

        # gh-26429
        msg = "2 columns passed, passed data had 10 columns"
        with pytest.raises(ValueError, match=msg):
            DataFrame((range(10), range(10, 20)), columns=("ones", "twos"))

        msg = "If using all scalar values, you must pass an index"
        with pytest.raises(ValueError, match=msg):
            DataFrame({"a": False, "b": True})

    def test_constructor_subclass_dict(self, dict_subclass):
        # Test for passing dict subclass to constructor
        data = {
            "col1": dict_subclass((x, 10.0 * x) for x in range(10)),
            "col2": dict_subclass((x, 20.0 * x) for x in range(10)),
        }
        df = DataFrame(data)
        refdf = DataFrame({col: dict(val.items()) for col, val in data.items()})
        tm.assert_frame_equal(refdf, df)

        data = dict_subclass(data.items())
        df = DataFrame(data)
        tm.assert_frame_equal(refdf, df)

    def test_constructor_defaultdict(self, float_frame):
        # try with defaultdict
        data = {}
        float_frame.loc[: float_frame.index[10], "B"] = np.nan

        for k, v in float_frame.items():
            dct = defaultdict(dict)
            dct.update(v.to_dict())
            data[k] = dct
        frame = DataFrame(data)
        expected = frame.reindex(index=float_frame.index)
        tm.assert_frame_equal(float_frame, expected)

    def test_constructor_dict_block(self):
        expected = np.array([[4.0, 3.0, 2.0, 1.0]])
        df = DataFrame(
            {"d": [4.0], "c": [3.0], "b": [2.0], "a": [1.0]},
            columns=["d", "c", "b", "a"],
        )
        tm.assert_numpy_array_equal(df.values, expected)

    def test_constructor_dict_cast(self):
        # cast float tests
        test_data = {"A": {"1": 1, "2": 2}, "B": {"1": "1", "2": "2", "3": "3"}}
        frame = DataFrame(test_data, dtype=float)
        assert len(frame) == 3
        assert frame["B"].dtype == np.float64
        assert frame["A"].dtype == np.float64

        frame = DataFrame(test_data)
        assert len(frame) == 3
        assert frame["B"].dtype == np.object_
        assert frame["A"].dtype == np.float64

    def test_constructor_dict_cast2(self):
        # can't cast to float
        test_data = {
            "A": dict(zip(range(20), tm.makeStringIndex(20))),
            "B": dict(zip(range(15), np.random.randn(15))),
        }
        with pytest.raises(ValueError, match="could not convert string"):
            DataFrame(test_data, dtype=float)

    def test_constructor_dict_dont_upcast(self):
        d = {"Col1": {"Row1": "A String", "Row2": np.nan}}
        df = DataFrame(d)
        assert isinstance(df["Col1"]["Row2"], float)

    def test_constructor_dict_dont_upcast2(self):
        dm = DataFrame([[1, 2], ["a", "b"]], index=[1, 2], columns=[1, 2])
        assert isinstance(dm[1][1], int)

    def test_constructor_dict_of_tuples(self):
        # GH #1491
        data = {"a": (1, 2, 3), "b": (4, 5, 6)}

        result = DataFrame(data)
        expected = DataFrame({k: list(v) for k, v in data.items()})
        tm.assert_frame_equal(result, expected, check_dtype=False)

    def test_constructor_dict_of_ranges(self):
        # GH 26356
        data = {"a": range(3), "b": range(3, 6)}

        result = DataFrame(data)
        expected = DataFrame({"a": [0, 1, 2], "b": [3, 4, 5]})
        tm.assert_frame_equal(result, expected)

    def test_constructor_dict_of_iterators(self):
        # GH 26349
        data = {"a": iter(range(3)), "b": reversed(range(3))}

        result = DataFrame(data)
        expected = DataFrame({"a": [0, 1, 2], "b": [2, 1, 0]})
        tm.assert_frame_equal(result, expected)

    def test_constructor_dict_of_generators(self):
        # GH 26349
        data = {"a": (i for i in (range(3))), "b": (i for i in reversed(range(3)))}
        result = DataFrame(data)
        expected = DataFrame({"a": [0, 1, 2], "b": [2, 1, 0]})
        tm.assert_frame_equal(result, expected)

    def test_constructor_dict_multiindex(self):
        d = {
            ("a", "a"): {("i", "i"): 0, ("i", "j"): 1, ("j", "i"): 2},
            ("b", "a"): {("i", "i"): 6, ("i", "j"): 5, ("j", "i"): 4},
            ("b", "c"): {("i", "i"): 7, ("i", "j"): 8, ("j", "i"): 9},
        }
        _d = sorted(d.items())
        df = DataFrame(d)
        expected = DataFrame(
            [x[1] for x in _d], index=MultiIndex.from_tuples([x[0] for x in _d])
        ).T
        expected.index = MultiIndex.from_tuples(expected.index)
        tm.assert_frame_equal(
            df,
            expected,
        )

        d["z"] = {"y": 123.0, ("i", "i"): 111, ("i", "j"): 111, ("j", "i"): 111}
        _d.insert(0, ("z", d["z"]))
        expected = DataFrame(
            [x[1] for x in _d], index=Index([x[0] for x in _d], tupleize_cols=False)
        ).T
        expected.index = Index(expected.index, tupleize_cols=False)
        df = DataFrame(d)
        df = df.reindex(columns=expected.columns, index=expected.index)
        tm.assert_frame_equal(df, expected)

    def test_constructor_dict_datetime64_index(self):
        # GH 10160
        dates_as_str = ["1984-02-19", "1988-11-06", "1989-12-03", "1990-03-15"]

        def create_data(constructor):
            return {i: {constructor(s): 2 * i} for i, s in enumerate(dates_as_str)}

        data_datetime64 = create_data(np.datetime64)
        data_datetime = create_data(lambda x: datetime.strptime(x, "%Y-%m-%d"))
        data_Timestamp = create_data(Timestamp)

        expected = DataFrame(
            [
                {0: 0, 1: None, 2: None, 3: None},
                {0: None, 1: 2, 2: None, 3: None},
                {0: None, 1: None, 2: 4, 3: None},
                {0: None, 1: None, 2: None, 3: 6},
            ],
            index=[Timestamp(dt) for dt in dates_as_str],
        )

        result_datetime64 = DataFrame(data_datetime64)
        result_datetime = DataFrame(data_datetime)
        result_Timestamp = DataFrame(data_Timestamp)
        tm.assert_frame_equal(result_datetime64, expected)
        tm.assert_frame_equal(result_datetime, expected)
        tm.assert_frame_equal(result_Timestamp, expected)

    @pytest.mark.parametrize(
        "klass,name",
        [
            (lambda x: np.timedelta64(x, "D"), "timedelta64"),
            (lambda x: timedelta(days=x), "pytimedelta"),
            (lambda x: Timedelta(x, "D"), "Timedelta[ns]"),
            (lambda x: Timedelta(x, "D").as_unit("s"), "Timedelta[s]"),
        ],
    )
    def test_constructor_dict_timedelta64_index(self, klass, name):
        # GH 10160
        td_as_int = [1, 2, 3, 4]

        data = {i: {klass(s): 2 * i} for i, s in enumerate(td_as_int)}

        expected = DataFrame(
            [
                {0: 0, 1: None, 2: None, 3: None},
                {0: None, 1: 2, 2: None, 3: None},
                {0: None, 1: None, 2: 4, 3: None},
                {0: None, 1: None, 2: None, 3: 6},
            ],
            index=[Timedelta(td, "D") for td in td_as_int],
        )

        result = DataFrame(data)

        tm.assert_frame_equal(result, expected)

    def test_constructor_period_dict(self):
        # PeriodIndex
        a = pd.PeriodIndex(["2012-01", "NaT", "2012-04"], freq="M")
        b = pd.PeriodIndex(["2012-02-01", "2012-03-01", "NaT"], freq="D")
        df = DataFrame({"a": a, "b": b})
        assert df["a"].dtype == a.dtype
        assert df["b"].dtype == b.dtype

        # list of periods
        df = DataFrame({"a": a.astype(object).tolist(), "b": b.astype(object).tolist()})
        assert df["a"].dtype == a.dtype
        assert df["b"].dtype == b.dtype

    def test_constructor_dict_extension_scalar(self, ea_scalar_and_dtype):
        ea_scalar, ea_dtype = ea_scalar_and_dtype
        df = DataFrame({"a": ea_scalar}, index=[0])
        assert df["a"].dtype == ea_dtype

        expected = DataFrame(index=[0], columns=["a"], data=ea_scalar)

        tm.assert_frame_equal(df, expected)

    @pytest.mark.parametrize(
        "data,dtype",
        [
            (Period("2020-01"), PeriodDtype("M")),
            (Interval(left=0, right=5), IntervalDtype("int64", "right")),
            (
                Timestamp("2011-01-01", tz="US/Eastern"),
                DatetimeTZDtype(tz="US/Eastern"),
            ),
        ],
    )
    def test_constructor_extension_scalar_data(self, data, dtype):
        # GH 34832
        df = DataFrame(index=[0, 1], columns=["a", "b"], data=data)

        assert df["a"].dtype == dtype
        assert df["b"].dtype == dtype

        arr = pd.array([data] * 2, dtype=dtype)
        expected = DataFrame({"a": arr, "b": arr})

        tm.assert_frame_equal(df, expected)

    def test_nested_dict_frame_constructor(self):
        rng = pd.period_range("1/1/2000", periods=5)
        df = DataFrame(np.random.randn(10, 5), columns=rng)

        data = {}
        for col in df.columns:
            for row in df.index:
                data.setdefault(col, {})[row] = df._get_value(row, col)

        result = DataFrame(data, columns=rng)
        tm.assert_frame_equal(result, df)

        data = {}
        for col in df.columns:
            for row in df.index:
                data.setdefault(row, {})[col] = df._get_value(row, col)

        result = DataFrame(data, index=rng).T
        tm.assert_frame_equal(result, df)

    def _check_basic_constructor(self, empty):
        # mat: 2d matrix with shape (3, 2) to input. empty - makes sized
        # objects
        mat = empty((2, 3), dtype=float)
        # 2-D input
        frame = DataFrame(mat, columns=["A", "B", "C"], index=[1, 2])

        assert len(frame.index) == 2
        assert len(frame.columns) == 3

        # 1-D input
        frame = DataFrame(empty((3,)), columns=["A"], index=[1, 2, 3])
        assert len(frame.index) == 3
        assert len(frame.columns) == 1

        if empty is not np.ones:
            msg = r"Cannot convert non-finite values \(NA or inf\) to integer"
            with pytest.raises(IntCastingNaNError, match=msg):
                DataFrame(mat, columns=["A", "B", "C"], index=[1, 2], dtype=np.int64)
            return
        else:
            frame = DataFrame(
                mat, columns=["A", "B", "C"], index=[1, 2], dtype=np.int64
            )
            assert frame.values.dtype == np.int64

        # wrong size axis labels
        msg = r"Shape of passed values is \(2, 3\), indices imply \(1, 3\)"
        with pytest.raises(ValueError, match=msg):
            DataFrame(mat, columns=["A", "B", "C"], index=[1])
        msg = r"Shape of passed values is \(2, 3\), indices imply \(2, 2\)"
        with pytest.raises(ValueError, match=msg):
            DataFrame(mat, columns=["A", "B"], index=[1, 2])

        # higher dim raise exception
        with pytest.raises(ValueError, match="Must pass 2-d input"):
            DataFrame(empty((3, 3, 3)), columns=["A", "B", "C"], index=[1])

        # automatic labeling
        frame = DataFrame(mat)
        tm.assert_index_equal(frame.index, Index(range(2)), exact=True)
        tm.assert_index_equal(frame.columns, Index(range(3)), exact=True)

        frame = DataFrame(mat, index=[1, 2])
        tm.assert_index_equal(frame.columns, Index(range(3)), exact=True)

        frame = DataFrame(mat, columns=["A", "B", "C"])
        tm.assert_index_equal(frame.index, Index(range(2)), exact=True)

        # 0-length axis
        frame = DataFrame(empty((0, 3)))
        assert len(frame.index) == 0

        frame = DataFrame(empty((3, 0)))
        assert len(frame.columns) == 0

    def test_constructor_ndarray(self):
        self._check_basic_constructor(np.ones)

        frame = DataFrame(["foo", "bar"], index=[0, 1], columns=["A"])
        assert len(frame) == 2

    def test_constructor_maskedarray(self):
        self._check_basic_constructor(ma.masked_all)

        # Check non-masked values
        mat = ma.masked_all((2, 3), dtype=float)
        mat[0, 0] = 1.0
        mat[1, 2] = 2.0
        frame = DataFrame(mat, columns=["A", "B", "C"], index=[1, 2])
        assert 1.0 == frame["A"][1]
        assert 2.0 == frame["C"][2]

        # what is this even checking??
        mat = ma.masked_all((2, 3), dtype=float)
        frame = DataFrame(mat, columns=["A", "B", "C"], index=[1, 2])
        assert np.all(~np.asarray(frame == frame))

    def test_constructor_maskedarray_nonfloat(self):
        # masked int promoted to float
        mat = ma.masked_all((2, 3), dtype=int)
        # 2-D input
        frame = DataFrame(mat, columns=["A", "B", "C"], index=[1, 2])

        assert len(frame.index) == 2
        assert len(frame.columns) == 3
        assert np.all(~np.asarray(frame == frame))

        # cast type
        frame = DataFrame(mat, columns=["A", "B", "C"], index=[1, 2], dtype=np.float64)
        assert frame.values.dtype == np.float64

        # Check non-masked values
        mat2 = ma.copy(mat)
        mat2[0, 0] = 1
        mat2[1, 2] = 2
        frame = DataFrame(mat2, columns=["A", "B", "C"], index=[1, 2])
        assert 1 == frame["A"][1]
        assert 2 == frame["C"][2]

        # masked np.datetime64 stays (use NaT as null)
        mat = ma.masked_all((2, 3), dtype="M8[ns]")
        # 2-D input
        frame = DataFrame(mat, columns=["A", "B", "C"], index=[1, 2])

        assert len(frame.index) == 2
        assert len(frame.columns) == 3
        assert isna(frame).values.all()

        # cast type
        msg = r"datetime64\[ns\] values and dtype=int64 is not supported"
        with pytest.raises(TypeError, match=msg):
            with warnings.catch_warnings():
                warnings.filterwarnings(
                    "ignore",
                    category=DeprecationWarning,
                    message="elementwise comparison failed",
                )
                DataFrame(mat, columns=["A", "B", "C"], index=[1, 2], dtype=np.int64)

        # Check non-masked values
        mat2 = ma.copy(mat)
        mat2[0, 0] = 1
        mat2[1, 2] = 2
        frame = DataFrame(mat2, columns=["A", "B", "C"], index=[1, 2])
        assert 1 == frame["A"].view("i8")[1]
        assert 2 == frame["C"].view("i8")[2]

        # masked bool promoted to object
        mat = ma.masked_all((2, 3), dtype=bool)
        # 2-D input
        frame = DataFrame(mat, columns=["A", "B", "C"], index=[1, 2])

        assert len(frame.index) == 2
        assert len(frame.columns) == 3
        assert np.all(~np.asarray(frame == frame))

        # cast type
        frame = DataFrame(mat, columns=["A", "B", "C"], index=[1, 2], dtype=object)
        assert frame.values.dtype == object

        # Check non-masked values
        mat2 = ma.copy(mat)
        mat2[0, 0] = True
        mat2[1, 2] = False
        frame = DataFrame(mat2, columns=["A", "B", "C"], index=[1, 2])
        assert frame["A"][1] is True
        assert frame["C"][2] is False

    def test_constructor_maskedarray_hardened(self):
        # Check numpy masked arrays with hard masks -- from GH24574
        mat_hard = ma.masked_all((2, 2), dtype=float).harden_mask()
        result = DataFrame(mat_hard, columns=["A", "B"], index=[1, 2])
        expected = DataFrame(
            {"A": [np.nan, np.nan], "B": [np.nan, np.nan]},
            columns=["A", "B"],
            index=[1, 2],
            dtype=float,
        )
        tm.assert_frame_equal(result, expected)
        # Check case where mask is hard but no data are masked
        mat_hard = ma.ones((2, 2), dtype=float).harden_mask()
        result = DataFrame(mat_hard, columns=["A", "B"], index=[1, 2])
        expected = DataFrame(
            {"A": [1.0, 1.0], "B": [1.0, 1.0]},
            columns=["A", "B"],
            index=[1, 2],
            dtype=float,
        )
        tm.assert_frame_equal(result, expected)

    def test_constructor_maskedrecarray_dtype(self):
        # Ensure constructor honors dtype
        data = np.ma.array(
            np.ma.zeros(5, dtype=[("date", "<f8"), ("price", "<f8")]), mask=[False] * 5
        )
        data = data.view(mrecords.mrecarray)
        with pytest.raises(TypeError, match=r"Pass \{name: data\[name\]"):
            # Support for MaskedRecords deprecated GH#40363
            DataFrame(data, dtype=int)

    def test_constructor_corner_shape(self):
        df = DataFrame(index=[])
        assert df.values.shape == (0, 0)

    @pytest.mark.parametrize(
        "data, index, columns, dtype, expected",
        [
            (None, list(range(10)), ["a", "b"], object, np.object_),
            (None, None, ["a", "b"], "int64", np.dtype("int64")),
            (None, list(range(10)), ["a", "b"], int, np.dtype("float64")),
            ({}, None, ["foo", "bar"], None, np.object_),
            ({"b": 1}, list(range(10)), list("abc"), int, np.dtype("float64")),
        ],
    )
    def test_constructor_dtype(self, data, index, columns, dtype, expected):
        df = DataFrame(data, index, columns, dtype)
        assert df.values.dtype == expected

    @pytest.mark.parametrize(
        "data,input_dtype,expected_dtype",
        (
            ([True, False, None], "boolean", pd.BooleanDtype),
            ([1.0, 2.0, None], "Float64", pd.Float64Dtype),
            ([1, 2, None], "Int64", pd.Int64Dtype),
            (["a", "b", "c"], "string", pd.StringDtype),
        ),
    )
    def test_constructor_dtype_nullable_extension_arrays(
        self, data, input_dtype, expected_dtype
    ):
        df = DataFrame({"a": data}, dtype=input_dtype)
        assert df["a"].dtype == expected_dtype()

    def test_constructor_scalar_inference(self):
        data = {"int": 1, "bool": True, "float": 3.0, "complex": 4j, "object": "foo"}
        df = DataFrame(data, index=np.arange(10))

        assert df["int"].dtype == np.int64
        assert df["bool"].dtype == np.bool_
        assert df["float"].dtype == np.float64
        assert df["complex"].dtype == np.complex128
        assert df["object"].dtype == np.object_

    def test_constructor_arrays_and_scalars(self):
        df = DataFrame({"a": np.random.randn(10), "b": True})
        exp = DataFrame({"a": df["a"].values, "b": [True] * 10})

        tm.assert_frame_equal(df, exp)
        with pytest.raises(ValueError, match="must pass an index"):
            DataFrame({"a": False, "b": True})

    def test_constructor_DataFrame(self, float_frame):
        df = DataFrame(float_frame)
        tm.assert_frame_equal(df, float_frame)

        df_casted = DataFrame(float_frame, dtype=np.int64)
        assert df_casted.values.dtype == np.int64

    def test_constructor_empty_dataframe(self):
        # GH 20624
        actual = DataFrame(DataFrame(), dtype="object")
        expected = DataFrame([], dtype="object")
        tm.assert_frame_equal(actual, expected)

    def test_constructor_more(self, float_frame):
        # used to be in test_matrix.py
        arr = np.random.randn(10)
        dm = DataFrame(arr, columns=["A"], index=np.arange(10))
        assert dm.values.ndim == 2

        arr = np.random.randn(0)
        dm = DataFrame(arr)
        assert dm.values.ndim == 2
        assert dm.values.ndim == 2

        # no data specified
        dm = DataFrame(columns=["A", "B"], index=np.arange(10))
        assert dm.values.shape == (10, 2)

        dm = DataFrame(columns=["A", "B"])
        assert dm.values.shape == (0, 2)

        dm = DataFrame(index=np.arange(10))
        assert dm.values.shape == (10, 0)

        # can't cast
        mat = np.array(["foo", "bar"], dtype=object).reshape(2, 1)
        msg = "could not convert string to float: 'foo'"
        with pytest.raises(ValueError, match=msg):
            DataFrame(mat, index=[0, 1], columns=[0], dtype=float)

        dm = DataFrame(DataFrame(float_frame._series))
        tm.assert_frame_equal(dm, float_frame)

        # int cast
        dm = DataFrame(
            {"A": np.ones(10, dtype=int), "B": np.ones(10, dtype=np.float64)},
            index=np.arange(10),
        )

        assert len(dm.columns) == 2
        assert dm.values.dtype == np.float64

    def test_constructor_empty_list(self):
        df = DataFrame([], index=[])
        expected = DataFrame(index=[])
        tm.assert_frame_equal(df, expected)

        # GH 9939
        df = DataFrame([], columns=["A", "B"])
        expected = DataFrame({}, columns=["A", "B"])
        tm.assert_frame_equal(df, expected)

        # Empty generator: list(empty_gen()) == []
        def empty_gen():
            yield from ()

        df = DataFrame(empty_gen(), columns=["A", "B"])
        tm.assert_frame_equal(df, expected)

    def test_constructor_list_of_lists(self):
        # GH #484
        df = DataFrame(data=[[1, "a"], [2, "b"]], columns=["num", "str"])
        assert is_integer_dtype(df["num"])
        assert df["str"].dtype == np.object_

        # GH 4851
        # list of 0-dim ndarrays
        expected = DataFrame({0: np.arange(10)})
        data = [np.array(x) for x in range(10)]
        result = DataFrame(data)
        tm.assert_frame_equal(result, expected)

    def test_nested_pandasarray_matches_nested_ndarray(self):
        # GH#43986
        ser = Series([1, 2])

        arr = np.array([None, None], dtype=object)
        arr[0] = ser
        arr[1] = ser * 2

        df = DataFrame(arr)
        expected = DataFrame(pd.array(arr))
        tm.assert_frame_equal(df, expected)
        assert df.shape == (2, 1)
        tm.assert_numpy_array_equal(df[0].values, arr)

    def test_constructor_list_like_data_nested_list_column(self):
        # GH 32173
        arrays = [list("abcd"), list("cdef")]
        result = DataFrame([[1, 2, 3, 4], [4, 5, 6, 7]], columns=arrays)

        mi = MultiIndex.from_arrays(arrays)
        expected = DataFrame([[1, 2, 3, 4], [4, 5, 6, 7]], columns=mi)

        tm.assert_frame_equal(result, expected)

    def test_constructor_wrong_length_nested_list_column(self):
        # GH 32173
        arrays = [list("abc"), list("cde")]

        msg = "3 columns passed, passed data had 4"
        with pytest.raises(ValueError, match=msg):
            DataFrame([[1, 2, 3, 4], [4, 5, 6, 7]], columns=arrays)

    def test_constructor_unequal_length_nested_list_column(self):
        # GH 32173
        arrays = [list("abcd"), list("cde")]

        # exception raised inside MultiIndex constructor
        msg = "all arrays must be same length"
        with pytest.raises(ValueError, match=msg):
            DataFrame([[1, 2, 3, 4], [4, 5, 6, 7]], columns=arrays)

    @pytest.mark.parametrize(
        "data",
        [
            [[Timestamp("2021-01-01")]],
            [{"x": Timestamp("2021-01-01")}],
            {"x": [Timestamp("2021-01-01")]},
            {"x": Timestamp("2021-01-01")},
        ],
    )
    def test_constructor_one_element_data_list(self, data):
        # GH#42810
        result = DataFrame(data, index=[0, 1, 2], columns=["x"])
        expected = DataFrame({"x": [Timestamp("2021-01-01")] * 3})
        tm.assert_frame_equal(result, expected)

    def test_constructor_sequence_like(self):
        # GH 3783
        # collections.Sequence like

        class DummyContainer(abc.Sequence):
            def __init__(self, lst) -> None:
                self._lst = lst

            def __getitem__(self, n):
                return self._lst.__getitem__(n)

            def __len__(self) -> int:
                return self._lst.__len__()

        lst_containers = [DummyContainer([1, "a"]), DummyContainer([2, "b"])]
        columns = ["num", "str"]
        result = DataFrame(lst_containers, columns=columns)
        expected = DataFrame([[1, "a"], [2, "b"]], columns=columns)
        tm.assert_frame_equal(result, expected, check_dtype=False)

    def test_constructor_stdlib_array(self):
        # GH 4297
        # support Array
        result = DataFrame({"A": array.array("i", range(10))})
        expected = DataFrame({"A": list(range(10))})
        tm.assert_frame_equal(result, expected, check_dtype=False)

        expected = DataFrame([list(range(10)), list(range(10))])
        result = DataFrame([array.array("i", range(10)), array.array("i", range(10))])
        tm.assert_frame_equal(result, expected, check_dtype=False)

    def test_constructor_range(self):
        # GH26342
        result = DataFrame(range(10))
        expected = DataFrame(list(range(10)))
        tm.assert_frame_equal(result, expected)

    def test_constructor_list_of_ranges(self):
        result = DataFrame([range(10), range(10)])
        expected = DataFrame([list(range(10)), list(range(10))])
        tm.assert_frame_equal(result, expected)

    def test_constructor_iterable(self):
        # GH 21987
        class Iter:
            def __iter__(self) -> Iterator:
                for i in range(10):
                    yield [1, 2, 3]

        expected = DataFrame([[1, 2, 3]] * 10)
        result = DataFrame(Iter())
        tm.assert_frame_equal(result, expected)

    def test_constructor_iterator(self):
        result = DataFrame(iter(range(10)))
        expected = DataFrame(list(range(10)))
        tm.assert_frame_equal(result, expected)

    def test_constructor_list_of_iterators(self):
        result = DataFrame([iter(range(10)), iter(range(10))])
        expected = DataFrame([list(range(10)), list(range(10))])
        tm.assert_frame_equal(result, expected)

    def test_constructor_generator(self):
        # related #2305

        gen1 = (i for i in range(10))
        gen2 = (i for i in range(10))

        expected = DataFrame([list(range(10)), list(range(10))])
        result = DataFrame([gen1, gen2])
        tm.assert_frame_equal(result, expected)

        gen = ([i, "a"] for i in range(10))
        result = DataFrame(gen)
        expected = DataFrame({0: range(10), 1: "a"})
        tm.assert_frame_equal(result, expected, check_dtype=False)

    def test_constructor_list_of_dicts(self):

        result = DataFrame([{}])
        expected = DataFrame(index=RangeIndex(1), columns=[])
        tm.assert_frame_equal(result, expected)

    def test_constructor_ordered_dict_nested_preserve_order(self):
        # see gh-18166
        nested1 = OrderedDict([("b", 1), ("a", 2)])
        nested2 = OrderedDict([("b", 2), ("a", 5)])
        data = OrderedDict([("col2", nested1), ("col1", nested2)])
        result = DataFrame(data)
        data = {"col2": [1, 2], "col1": [2, 5]}
        expected = DataFrame(data=data, index=["b", "a"])
        tm.assert_frame_equal(result, expected)

    @pytest.mark.parametrize("dict_type", [dict, OrderedDict])
    def test_constructor_ordered_dict_preserve_order(self, dict_type):
        # see gh-13304
        expected = DataFrame([[2, 1]], columns=["b", "a"])

        data = dict_type()
        data["b"] = [2]
        data["a"] = [1]

        result = DataFrame(data)
        tm.assert_frame_equal(result, expected)

        data = dict_type()
        data["b"] = 2
        data["a"] = 1

        result = DataFrame([data])
        tm.assert_frame_equal(result, expected)

    @pytest.mark.parametrize("dict_type", [dict, OrderedDict])
    def test_constructor_ordered_dict_conflicting_orders(self, dict_type):
        # the first dict element sets the ordering for the DataFrame,
        # even if there are conflicting orders from subsequent ones
        row_one = dict_type()
        row_one["b"] = 2
        row_one["a"] = 1

        row_two = dict_type()
        row_two["a"] = 1
        row_two["b"] = 2

        row_three = {"b": 2, "a": 1}

        expected = DataFrame([[2, 1], [2, 1]], columns=["b", "a"])
        result = DataFrame([row_one, row_two])
        tm.assert_frame_equal(result, expected)

        expected = DataFrame([[2, 1], [2, 1], [2, 1]], columns=["b", "a"])
        result = DataFrame([row_one, row_two, row_three])
        tm.assert_frame_equal(result, expected)

    def test_constructor_list_of_series_aligned_index(self):
        series = [Series(i, index=["b", "a", "c"], name=str(i)) for i in range(3)]
        result = DataFrame(series)
        expected = DataFrame(
            {"b": [0, 1, 2], "a": [0, 1, 2], "c": [0, 1, 2]},
            columns=["b", "a", "c"],
            index=["0", "1", "2"],
        )
        tm.assert_frame_equal(result, expected)

    def test_constructor_list_of_derived_dicts(self):
        class CustomDict(dict):
            pass

        d = {"a": 1.5, "b": 3}

        data_custom = [CustomDict(d)]
        data = [d]

        result_custom = DataFrame(data_custom)
        result = DataFrame(data)
        tm.assert_frame_equal(result, result_custom)

    def test_constructor_ragged(self):
        data = {"A": np.random.randn(10), "B": np.random.randn(8)}
        with pytest.raises(ValueError, match="All arrays must be of the same length"):
            DataFrame(data)

    def test_constructor_scalar(self):
        idx = Index(range(3))
        df = DataFrame({"a": 0}, index=idx)
        expected = DataFrame({"a": [0, 0, 0]}, index=idx)
        tm.assert_frame_equal(df, expected, check_dtype=False)

    def test_constructor_Series_copy_bug(self, float_frame):
        df = DataFrame(float_frame["A"], index=float_frame.index, columns=["A"])
        df.copy()

    def test_constructor_mixed_dict_and_Series(self):
        data = {}
        data["A"] = {"foo": 1, "bar": 2, "baz": 3}
        data["B"] = Series([4, 3, 2, 1], index=["bar", "qux", "baz", "foo"])

        result = DataFrame(data)
        assert result.index.is_monotonic_increasing

        # ordering ambiguous, raise exception
        with pytest.raises(ValueError, match="ambiguous ordering"):
            DataFrame({"A": ["a", "b"], "B": {"a": "a", "b": "b"}})

        # this is OK though
        result = DataFrame({"A": ["a", "b"], "B": Series(["a", "b"], index=["a", "b"])})
        expected = DataFrame({"A": ["a", "b"], "B": ["a", "b"]}, index=["a", "b"])
        tm.assert_frame_equal(result, expected)

    def test_constructor_mixed_type_rows(self):
        # Issue 25075
        data = [[1, 2], (3, 4)]
        result = DataFrame(data)
        expected = DataFrame([[1, 2], [3, 4]])
        tm.assert_frame_equal(result, expected)

    @pytest.mark.parametrize(
        "tuples,lists",
        [
            ((), []),
            ((()), []),
            (((), ()), [(), ()]),
            (((), ()), [[], []]),
            (([], []), [[], []]),
            (([1], [2]), [[1], [2]]),  # GH 32776
            (([1, 2, 3], [4, 5, 6]), [[1, 2, 3], [4, 5, 6]]),
        ],
    )
    def test_constructor_tuple(self, tuples, lists):
        # GH 25691
        result = DataFrame(tuples)
        expected = DataFrame(lists)
        tm.assert_frame_equal(result, expected)

    def test_constructor_list_of_tuples(self):
        result = DataFrame({"A": [(1, 2), (3, 4)]})
        expected = DataFrame({"A": Series([(1, 2), (3, 4)])})
        tm.assert_frame_equal(result, expected)

    def test_constructor_list_of_namedtuples(self):
        # GH11181
        named_tuple = namedtuple("Pandas", list("ab"))
        tuples = [named_tuple(1, 3), named_tuple(2, 4)]
        expected = DataFrame({"a": [1, 2], "b": [3, 4]})
        result = DataFrame(tuples)
        tm.assert_frame_equal(result, expected)

        # with columns
        expected = DataFrame({"y": [1, 2], "z": [3, 4]})
        result = DataFrame(tuples, columns=["y", "z"])
        tm.assert_frame_equal(result, expected)

    def test_constructor_list_of_dataclasses(self):
        # GH21910
        Point = make_dataclass("Point", [("x", int), ("y", int)])

        data = [Point(0, 3), Point(1, 3)]
        expected = DataFrame({"x": [0, 1], "y": [3, 3]})
        result = DataFrame(data)
        tm.assert_frame_equal(result, expected)

    def test_constructor_list_of_dataclasses_with_varying_types(self):
        # GH21910
        # varying types
        Point = make_dataclass("Point", [("x", int), ("y", int)])
        HLine = make_dataclass("HLine", [("x0", int), ("x1", int), ("y", int)])

        data = [Point(0, 3), HLine(1, 3, 3)]

        expected = DataFrame(
            {"x": [0, np.nan], "y": [3, 3], "x0": [np.nan, 1], "x1": [np.nan, 3]}
        )
        result = DataFrame(data)
        tm.assert_frame_equal(result, expected)

    def test_constructor_list_of_dataclasses_error_thrown(self):
        # GH21910
        Point = make_dataclass("Point", [("x", int), ("y", int)])

        # expect TypeError
        msg = "asdict() should be called on dataclass instances"
        with pytest.raises(TypeError, match=re.escape(msg)):
            DataFrame([Point(0, 0), {"x": 1, "y": 0}])

    def test_constructor_list_of_dict_order(self):
        # GH10056
        data = [
            {"First": 1, "Second": 4, "Third": 7, "Fourth": 10},
            {"Second": 5, "First": 2, "Fourth": 11, "Third": 8},
            {"Second": 6, "First": 3, "Fourth": 12, "Third": 9, "YYY": 14, "XXX": 13},
        ]
        expected = DataFrame(
            {
                "First": [1, 2, 3],
                "Second": [4, 5, 6],
                "Third": [7, 8, 9],
                "Fourth": [10, 11, 12],
                "YYY": [None, None, 14],
                "XXX": [None, None, 13],
            }
        )
        result = DataFrame(data)
        tm.assert_frame_equal(result, expected)

    def test_constructor_Series_named(self):
        a = Series([1, 2, 3], index=["a", "b", "c"], name="x")
        df = DataFrame(a)
        assert df.columns[0] == "x"
        tm.assert_index_equal(df.index, a.index)

        # ndarray like
        arr = np.random.randn(10)
        s = Series(arr, name="x")
        df = DataFrame(s)
        expected = DataFrame({"x": s})
        tm.assert_frame_equal(df, expected)

        s = Series(arr, index=range(3, 13))
        df = DataFrame(s)
        expected = DataFrame({0: s})
        tm.assert_frame_equal(df, expected)

        msg = r"Shape of passed values is \(10, 1\), indices imply \(10, 2\)"
        with pytest.raises(ValueError, match=msg):
            DataFrame(s, columns=[1, 2])

        # #2234
        a = Series([], name="x", dtype=object)
        df = DataFrame(a)
        assert df.columns[0] == "x"

        # series with name and w/o
        s1 = Series(arr, name="x")
        df = DataFrame([s1, arr]).T
        expected = DataFrame({"x": s1, "Unnamed 0": arr}, columns=["x", "Unnamed 0"])
        tm.assert_frame_equal(df, expected)

        # this is a bit non-intuitive here; the series collapse down to arrays
        df = DataFrame([arr, s1]).T
        expected = DataFrame({1: s1, 0: arr}, columns=[0, 1])
        tm.assert_frame_equal(df, expected)

    def test_constructor_Series_named_and_columns(self):
        # GH 9232 validation

        s0 = Series(range(5), name=0)
        s1 = Series(range(5), name=1)

        # matching name and column gives standard frame
        tm.assert_frame_equal(DataFrame(s0, columns=[0]), s0.to_frame())
        tm.assert_frame_equal(DataFrame(s1, columns=[1]), s1.to_frame())

        # non-matching produces empty frame
        assert DataFrame(s0, columns=[1]).empty
        assert DataFrame(s1, columns=[0]).empty

    def test_constructor_Series_differently_indexed(self):
        # name
        s1 = Series([1, 2, 3], index=["a", "b", "c"], name="x")

        # no name
        s2 = Series([1, 2, 3], index=["a", "b", "c"])

        other_index = Index(["a", "b"])

        df1 = DataFrame(s1, index=other_index)
        exp1 = DataFrame(s1.reindex(other_index))
        assert df1.columns[0] == "x"
        tm.assert_frame_equal(df1, exp1)

        df2 = DataFrame(s2, index=other_index)
        exp2 = DataFrame(s2.reindex(other_index))
        assert df2.columns[0] == 0
        tm.assert_index_equal(df2.index, other_index)
        tm.assert_frame_equal(df2, exp2)

    @pytest.mark.parametrize(
        "name_in1,name_in2,name_in3,name_out",
        [
            ("idx", "idx", "idx", "idx"),
            ("idx", "idx", None, None),
            ("idx", None, None, None),
            ("idx1", "idx2", None, None),
            ("idx1", "idx1", "idx2", None),
            ("idx1", "idx2", "idx3", None),
            (None, None, None, None),
        ],
    )
    def test_constructor_index_names(self, name_in1, name_in2, name_in3, name_out):
        # GH13475
        indices = [
            Index(["a", "b", "c"], name=name_in1),
            Index(["b", "c", "d"], name=name_in2),
            Index(["c", "d", "e"], name=name_in3),
        ]
        series = {
            c: Series([0, 1, 2], index=i) for i, c in zip(indices, ["x", "y", "z"])
        }
        result = DataFrame(series)

        exp_ind = Index(["a", "b", "c", "d", "e"], name=name_out)
        expected = DataFrame(
            {
                "x": [0, 1, 2, np.nan, np.nan],
                "y": [np.nan, 0, 1, 2, np.nan],
                "z": [np.nan, np.nan, 0, 1, 2],
            },
            index=exp_ind,
        )

        tm.assert_frame_equal(result, expected)

    def test_constructor_manager_resize(self, float_frame):
        index = list(float_frame.index[:5])
        columns = list(float_frame.columns[:3])

        result = DataFrame(float_frame._mgr, index=index, columns=columns)
        tm.assert_index_equal(result.index, Index(index))
        tm.assert_index_equal(result.columns, Index(columns))

    def test_constructor_mix_series_nonseries(self, float_frame):
        df = DataFrame(
            {"A": float_frame["A"], "B": list(float_frame["B"])}, columns=["A", "B"]
        )
        tm.assert_frame_equal(df, float_frame.loc[:, ["A", "B"]])

        msg = "does not match index length"
        with pytest.raises(ValueError, match=msg):
            DataFrame({"A": float_frame["A"], "B": list(float_frame["B"])[:-2]})

    def test_constructor_miscast_na_int_dtype(self):
        msg = r"Cannot convert non-finite values \(NA or inf\) to integer"

        with pytest.raises(IntCastingNaNError, match=msg):
            DataFrame([[np.nan, 1], [1, 0]], dtype=np.int64)

    def test_constructor_column_duplicates(self):
        # it works! #2079
        df = DataFrame([[8, 5]], columns=["a", "a"])
        edf = DataFrame([[8, 5]])
        edf.columns = ["a", "a"]

        tm.assert_frame_equal(df, edf)

        idf = DataFrame.from_records([(8, 5)], columns=["a", "a"])

        tm.assert_frame_equal(idf, edf)

    def test_constructor_empty_with_string_dtype(self):
        # GH 9428
        expected = DataFrame(index=[0, 1], columns=[0, 1], dtype=object)

        df = DataFrame(index=[0, 1], columns=[0, 1], dtype=str)
        tm.assert_frame_equal(df, expected)
        df = DataFrame(index=[0, 1], columns=[0, 1], dtype=np.str_)
        tm.assert_frame_equal(df, expected)
        df = DataFrame(index=[0, 1], columns=[0, 1], dtype=np.unicode_)
        tm.assert_frame_equal(df, expected)
        df = DataFrame(index=[0, 1], columns=[0, 1], dtype="U5")
        tm.assert_frame_equal(df, expected)

    def test_constructor_empty_with_string_extension(self, nullable_string_dtype):
        # GH 34915
        expected = DataFrame(columns=["c1"], dtype=nullable_string_dtype)
        df = DataFrame(columns=["c1"], dtype=nullable_string_dtype)
        tm.assert_frame_equal(df, expected)

    def test_constructor_single_value(self):
        # expecting single value upcasting here
        df = DataFrame(0.0, index=[1, 2, 3], columns=["a", "b", "c"])
        tm.assert_frame_equal(
            df, DataFrame(np.zeros(df.shape).astype("float64"), df.index, df.columns)
        )

        df = DataFrame(0, index=[1, 2, 3], columns=["a", "b", "c"])
        tm.assert_frame_equal(
            df, DataFrame(np.zeros(df.shape).astype("int64"), df.index, df.columns)
        )

        df = DataFrame("a", index=[1, 2], columns=["a", "c"])
        tm.assert_frame_equal(
            df,
            DataFrame(
                np.array([["a", "a"], ["a", "a"]], dtype=object),
                index=[1, 2],
                columns=["a", "c"],
            ),
        )

        msg = "DataFrame constructor not properly called!"
        with pytest.raises(ValueError, match=msg):
            DataFrame("a", [1, 2])
        with pytest.raises(ValueError, match=msg):
            DataFrame("a", columns=["a", "c"])

        msg = "incompatible data and dtype"
        with pytest.raises(TypeError, match=msg):
            DataFrame("a", [1, 2], ["a", "c"], float)

    def test_constructor_with_datetimes(self):
        intname = np.dtype(np.int_).name
        floatname = np.dtype(np.float_).name
        datetime64name = np.dtype("M8[ns]").name
        objectname = np.dtype(np.object_).name

        # single item
        df = DataFrame(
            {
                "A": 1,
                "B": "foo",
                "C": "bar",
                "D": Timestamp("20010101"),
                "E": datetime(2001, 1, 2, 0, 0),
            },
            index=np.arange(10),
        )
        result = df.dtypes
        expected = Series(
            [np.dtype("int64")]
            + [np.dtype(objectname)] * 2
            + [np.dtype(datetime64name)] * 2,
            index=list("ABCDE"),
        )
        tm.assert_series_equal(result, expected)

        # check with ndarray construction ndim==0 (e.g. we are passing a ndim 0
        # ndarray with a dtype specified)
        df = DataFrame(
            {
                "a": 1.0,
                "b": 2,
                "c": "foo",
                floatname: np.array(1.0, dtype=floatname),
                intname: np.array(1, dtype=intname),
            },
            index=np.arange(10),
        )
        result = df.dtypes
        expected = Series(
            [np.dtype("float64")]
            + [np.dtype("int64")]
            + [np.dtype("object")]
            + [np.dtype("float64")]
            + [np.dtype(intname)],
            index=["a", "b", "c", floatname, intname],
        )
        tm.assert_series_equal(result, expected)

        # check with ndarray construction ndim>0
        df = DataFrame(
            {
                "a": 1.0,
                "b": 2,
                "c": "foo",
                floatname: np.array([1.0] * 10, dtype=floatname),
                intname: np.array([1] * 10, dtype=intname),
            },
            index=np.arange(10),
        )
        result = df.dtypes
        expected = Series(
            [np.dtype("float64")]
            + [np.dtype("int64")]
            + [np.dtype("object")]
            + [np.dtype("float64")]
            + [np.dtype(intname)],
            index=["a", "b", "c", floatname, intname],
        )
        tm.assert_series_equal(result, expected)

    def test_constructor_with_datetimes1(self):

        # GH 2809
        ind = date_range(start="2000-01-01", freq="D", periods=10)
        datetimes = [ts.to_pydatetime() for ts in ind]
        datetime_s = Series(datetimes)
        assert datetime_s.dtype == "M8[ns]"

    def test_constructor_with_datetimes2(self):
        # GH 2810
        ind = date_range(start="2000-01-01", freq="D", periods=10)
        datetimes = [ts.to_pydatetime() for ts in ind]
        dates = [ts.date() for ts in ind]
        df = DataFrame(datetimes, columns=["datetimes"])
        df["dates"] = dates
        result = df.dtypes
        expected = Series(
            [np.dtype("datetime64[ns]"), np.dtype("object")],
            index=["datetimes", "dates"],
        )
        tm.assert_series_equal(result, expected)

    def test_constructor_with_datetimes3(self):
        # GH 7594
        # don't coerce tz-aware
        tz = pytz.timezone("US/Eastern")
        dt = tz.localize(datetime(2012, 1, 1))

        df = DataFrame({"End Date": dt}, index=[0])
        assert df.iat[0, 0] == dt
        tm.assert_series_equal(
            df.dtypes, Series({"End Date": "datetime64[ns, US/Eastern]"})
        )

        df = DataFrame([{"End Date": dt}])
        assert df.iat[0, 0] == dt
        tm.assert_series_equal(
            df.dtypes, Series({"End Date": "datetime64[ns, US/Eastern]"})
        )

    def test_constructor_with_datetimes4(self):
        # tz-aware (UTC and other tz's)
        # GH 8411
        dr = date_range("20130101", periods=3)
        df = DataFrame({"value": dr})
        assert df.iat[0, 0].tz is None
        dr = date_range("20130101", periods=3, tz="UTC")
        df = DataFrame({"value": dr})
        assert str(df.iat[0, 0].tz) == "UTC"
        dr = date_range("20130101", periods=3, tz="US/Eastern")
        df = DataFrame({"value": dr})
        assert str(df.iat[0, 0].tz) == "US/Eastern"

    def test_constructor_with_datetimes5(self):
        # GH 7822
        # preserver an index with a tz on dict construction
        i = date_range("1/1/2011", periods=5, freq="10s", tz="US/Eastern")

        expected = DataFrame({"a": i.to_series().reset_index(drop=True)})
        df = DataFrame()
        df["a"] = i
        tm.assert_frame_equal(df, expected)

        df = DataFrame({"a": i})
        tm.assert_frame_equal(df, expected)

    def test_constructor_with_datetimes6(self):
        # multiples
        i = date_range("1/1/2011", periods=5, freq="10s", tz="US/Eastern")
        i_no_tz = date_range("1/1/2011", periods=5, freq="10s")
        df = DataFrame({"a": i, "b": i_no_tz})
        expected = DataFrame({"a": i.to_series().reset_index(drop=True), "b": i_no_tz})
        tm.assert_frame_equal(df, expected)

    @pytest.mark.parametrize(
        "arr",
        [
            np.array([None, None, None, None, datetime.now(), None]),
            np.array([None, None, datetime.now(), None]),
            [[np.datetime64("NaT")], [None]],
            [[np.datetime64("NaT")], [pd.NaT]],
            [[None], [np.datetime64("NaT")]],
            [[None], [pd.NaT]],
            [[pd.NaT], [np.datetime64("NaT")]],
            [[pd.NaT], [None]],
        ],
    )
    def test_constructor_datetimes_with_nulls(self, arr):
        # gh-15869, GH#11220
        result = DataFrame(arr).dtypes
        expected = Series([np.dtype("datetime64[ns]")])
        tm.assert_series_equal(result, expected)

    @pytest.mark.parametrize("order", ["K", "A", "C", "F"])
    @pytest.mark.parametrize(
        "unit",
        ["M", "D", "h", "m", "s", "ms", "us", "ns"],
    )
    def test_constructor_datetimes_non_ns(self, order, unit):
        dtype = f"datetime64[{unit}]"
        na = np.array(
            [
                ["2015-01-01", "2015-01-02", "2015-01-03"],
                ["2017-01-01", "2017-01-02", "2017-02-03"],
            ],
            dtype=dtype,
            order=order,
        )
        df = DataFrame(na)
        expected = DataFrame(na.astype("M8[ns]"))
        if unit in ["M", "D", "h", "m"]:
            with pytest.raises(TypeError, match="Cannot cast"):
                expected.astype(dtype)

            # instead the constructor casts to the closest supported reso, i.e. "s"
            expected = expected.astype("datetime64[s]")
        else:
            expected = expected.astype(dtype=dtype)

        tm.assert_frame_equal(df, expected)

    @pytest.mark.parametrize("order", ["K", "A", "C", "F"])
    @pytest.mark.parametrize(
        "unit",
        [
            "D",
            "h",
            "m",
            "s",
            "ms",
            "us",
            "ns",
        ],
    )
    def test_constructor_timedelta_non_ns(self, order, unit):
        dtype = f"timedelta64[{unit}]"
        na = np.array(
            [
                [np.timedelta64(1, "D"), np.timedelta64(2, "D")],
                [np.timedelta64(4, "D"), np.timedelta64(5, "D")],
            ],
            dtype=dtype,
            order=order,
        )
        df = DataFrame(na)
        if unit in ["D", "h", "m"]:
            # we get the nearest supported unit, i.e. "s"
            exp_unit = "s"
        else:
            exp_unit = unit
        exp_dtype = np.dtype(f"m8[{exp_unit}]")
        expected = DataFrame(
            [
                [Timedelta(1, "D"), Timedelta(2, "D")],
                [Timedelta(4, "D"), Timedelta(5, "D")],
            ],
            dtype=exp_dtype,
        )
        # TODO(2.0): ideally we should get the same 'expected' without passing
        #  dtype=exp_dtype.
        tm.assert_frame_equal(df, expected)

    def test_constructor_for_list_with_dtypes(self):
        # test list of lists/ndarrays
        df = DataFrame([np.arange(5) for x in range(5)])
        result = df.dtypes
        expected = Series([np.dtype("int")] * 5)
        tm.assert_series_equal(result, expected)

        df = DataFrame([np.array(np.arange(5), dtype="int32") for x in range(5)])
        result = df.dtypes
        expected = Series([np.dtype("int32")] * 5)
        tm.assert_series_equal(result, expected)

        # overflow issue? (we always expected int64 upcasting here)
        df = DataFrame({"a": [2**31, 2**31 + 1]})
        assert df.dtypes.iloc[0] == np.dtype("int64")

        # GH #2751 (construction with no index specified), make sure we cast to
        # platform values
        df = DataFrame([1, 2])
        assert df.dtypes.iloc[0] == np.dtype("int64")

        df = DataFrame([1.0, 2.0])
        assert df.dtypes.iloc[0] == np.dtype("float64")

        df = DataFrame({"a": [1, 2]})
        assert df.dtypes.iloc[0] == np.dtype("int64")

        df = DataFrame({"a": [1.0, 2.0]})
        assert df.dtypes.iloc[0] == np.dtype("float64")

        df = DataFrame({"a": 1}, index=range(3))
        assert df.dtypes.iloc[0] == np.dtype("int64")

        df = DataFrame({"a": 1.0}, index=range(3))
        assert df.dtypes.iloc[0] == np.dtype("float64")

        # with object list
        df = DataFrame(
            {
                "a": [1, 2, 4, 7],
                "b": [1.2, 2.3, 5.1, 6.3],
                "c": list("abcd"),
                "d": [datetime(2000, 1, 1) for i in range(4)],
                "e": [1.0, 2, 4.0, 7],
            }
        )
        result = df.dtypes
        expected = Series(
            [
                np.dtype("int64"),
                np.dtype("float64"),
                np.dtype("object"),
                np.dtype("datetime64[ns]"),
                np.dtype("float64"),
            ],
            index=list("abcde"),
        )
        tm.assert_series_equal(result, expected)

    def test_constructor_frame_copy(self, float_frame):
        cop = DataFrame(float_frame, copy=True)
        cop["A"] = 5
        assert (cop["A"] == 5).all()
        assert not (float_frame["A"] == 5).all()

    def test_constructor_ndarray_copy(self, float_frame, using_array_manager):
        if not using_array_manager:
            df = DataFrame(float_frame.values)

            float_frame.values[5] = 5
            assert (df.values[5] == 5).all()

            df = DataFrame(float_frame.values, copy=True)
            float_frame.values[6] = 6
            assert not (df.values[6] == 6).all()
        else:
            arr = float_frame.values.copy()
            # default: copy to ensure contiguous arrays
            df = DataFrame(arr)
            assert df._mgr.arrays[0].flags.c_contiguous
            arr[0, 0] = 100
            assert df.iloc[0, 0] != 100

            # manually specify copy=False
            df = DataFrame(arr, copy=False)
            assert not df._mgr.arrays[0].flags.c_contiguous
            arr[0, 0] = 1000
            assert df.iloc[0, 0] == 1000

    def test_constructor_series_copy(self, float_frame):
        series = float_frame._series

        df = DataFrame({"A": series["A"]}, copy=True)
        # TODO can be replaced with `df.loc[:, "A"] = 5` after deprecation about
        # inplace mutation is enforced
        df.loc[df.index[0] : df.index[-1], "A"] = 5

        assert not (series["A"] == 5).all()

    @pytest.mark.parametrize(
        "df",
        [
            DataFrame([[1, 2, 3], [4, 5, 6]], index=[1, np.nan]),
            DataFrame([[1, 2, 3], [4, 5, 6]], columns=[1.1, 2.2, np.nan]),
            DataFrame([[0, 1, 2, 3], [4, 5, 6, 7]], columns=[np.nan, 1.1, 2.2, np.nan]),
            DataFrame(
                [[0.0, 1, 2, 3.0], [4, 5, 6, 7]], columns=[np.nan, 1.1, 2.2, np.nan]
            ),
            DataFrame([[0.0, 1, 2, 3.0], [4, 5, 6, 7]], columns=[np.nan, 1, 2, 2]),
        ],
    )
    def test_constructor_with_nas(self, df):
        # GH 5016
        # na's in indices
        # GH 21428 (non-unique columns)

        for i in range(len(df.columns)):
            df.iloc[:, i]

        indexer = np.arange(len(df.columns))[isna(df.columns)]

        # No NaN found -> error
        if len(indexer) == 0:
            with pytest.raises(KeyError, match="^nan$"):
                df.loc[:, np.nan]
        # single nan should result in Series
        elif len(indexer) == 1:
            tm.assert_series_equal(df.iloc[:, indexer[0]], df.loc[:, np.nan])
        # multiple nans should result in DataFrame
        else:
            tm.assert_frame_equal(df.iloc[:, indexer], df.loc[:, np.nan])

    def test_constructor_lists_to_object_dtype(self):
        # from #1074
        d = DataFrame({"a": [np.nan, False]})
        assert d["a"].dtype == np.object_
        assert not d["a"][1]

    def test_constructor_ndarray_categorical_dtype(self):
        cat = Categorical(["A", "B", "C"])
        arr = np.array(cat).reshape(-1, 1)
        arr = np.broadcast_to(arr, (3, 4))

        result = DataFrame(arr, dtype=cat.dtype)

        expected = DataFrame({0: cat, 1: cat, 2: cat, 3: cat})
        tm.assert_frame_equal(result, expected)

    def test_constructor_categorical(self):

        # GH8626

        # dict creation
        df = DataFrame({"A": list("abc")}, dtype="category")
        expected = Series(list("abc"), dtype="category", name="A")
        tm.assert_series_equal(df["A"], expected)

        # to_frame
        s = Series(list("abc"), dtype="category")
        result = s.to_frame()
        expected = Series(list("abc"), dtype="category", name=0)
        tm.assert_series_equal(result[0], expected)
        result = s.to_frame(name="foo")
        expected = Series(list("abc"), dtype="category", name="foo")
        tm.assert_series_equal(result["foo"], expected)

        # list-like creation
        df = DataFrame(list("abc"), dtype="category")
        expected = Series(list("abc"), dtype="category", name=0)
        tm.assert_series_equal(df[0], expected)

    def test_construct_from_1item_list_of_categorical(self):
        # pre-2.0 this behaved as DataFrame({0: cat}), in 2.0 we remove
        #  Categorical special case
        # ndim != 1
        cat = Categorical(list("abc"))
        df = DataFrame([cat])
        expected = DataFrame([cat.astype(object)])
        tm.assert_frame_equal(df, expected)

    def test_construct_from_list_of_categoricals(self):
        # pre-2.0 this behaved as DataFrame({0: cat}), in 2.0 we remove
        #  Categorical special case

        df = DataFrame([Categorical(list("abc")), Categorical(list("abd"))])
        expected = DataFrame([["a", "b", "c"], ["a", "b", "d"]])
        tm.assert_frame_equal(df, expected)

    def test_from_nested_listlike_mixed_types(self):
        # pre-2.0 this behaved as DataFrame({0: cat}), in 2.0 we remove
        #  Categorical special case
        # mixed
        df = DataFrame([Categorical(list("abc")), list("def")])
        expected = DataFrame([["a", "b", "c"], ["d", "e", "f"]])
        tm.assert_frame_equal(df, expected)

    def test_construct_from_listlikes_mismatched_lengths(self):
        df = DataFrame([Categorical(list("abc")), Categorical(list("abdefg"))])
        expected = DataFrame([list("abc"), list("abdefg")])
        tm.assert_frame_equal(df, expected)

    def test_constructor_categorical_series(self):

        items = [1, 2, 3, 1]
        exp = Series(items).astype("category")
        res = Series(items, dtype="category")
        tm.assert_series_equal(res, exp)

        items = ["a", "b", "c", "a"]
        exp = Series(items).astype("category")
        res = Series(items, dtype="category")
        tm.assert_series_equal(res, exp)

        # insert into frame with different index
        # GH 8076
        index = date_range("20000101", periods=3)
        expected = Series(
            Categorical(values=[np.nan, np.nan, np.nan], categories=["a", "b", "c"])
        )
        expected.index = index

        expected = DataFrame({"x": expected})
        df = DataFrame({"x": Series(["a", "b", "c"], dtype="category")}, index=index)
        tm.assert_frame_equal(df, expected)

    @pytest.mark.parametrize(
        "dtype",
        tm.ALL_NUMERIC_DTYPES
        + tm.DATETIME64_DTYPES
        + tm.TIMEDELTA64_DTYPES
        + tm.BOOL_DTYPES,
    )
    def test_check_dtype_empty_numeric_column(self, dtype):
        # GH24386: Ensure dtypes are set correctly for an empty DataFrame.
        # Empty DataFrame is generated via dictionary data with non-overlapping columns.
        data = DataFrame({"a": [1, 2]}, columns=["b"], dtype=dtype)

        assert data.b.dtype == dtype

    @pytest.mark.parametrize(
        "dtype", tm.STRING_DTYPES + tm.BYTES_DTYPES + tm.OBJECT_DTYPES
    )
    def test_check_dtype_empty_string_column(self, request, dtype, using_array_manager):
        # GH24386: Ensure dtypes are set correctly for an empty DataFrame.
        # Empty DataFrame is generated via dictionary data with non-overlapping columns.
        data = DataFrame({"a": [1, 2]}, columns=["b"], dtype=dtype)

        if using_array_manager and dtype in tm.BYTES_DTYPES:
            # TODO(ArrayManager) astype to bytes dtypes does not yet give object dtype
            td.mark_array_manager_not_yet_implemented(request)

        assert data.b.dtype.name == "object"

    def test_to_frame_with_falsey_names(self):
        # GH 16114
        result = Series(name=0, dtype=object).to_frame().dtypes
        expected = Series({0: object})
        tm.assert_series_equal(result, expected)

        result = DataFrame(Series(name=0, dtype=object)).dtypes
        tm.assert_series_equal(result, expected)

    @pytest.mark.arm_slow
    @pytest.mark.parametrize("dtype", [None, "uint8", "category"])
    def test_constructor_range_dtype(self, dtype):
        expected = DataFrame({"A": [0, 1, 2, 3, 4]}, dtype=dtype or "int64")

        # GH 26342
        result = DataFrame(range(5), columns=["A"], dtype=dtype)
        tm.assert_frame_equal(result, expected)

        # GH 16804
        result = DataFrame({"A": range(5)}, dtype=dtype)
        tm.assert_frame_equal(result, expected)

    def test_frame_from_list_subclass(self):
        # GH21226
        class List(list):
            pass

        expected = DataFrame([[1, 2, 3], [4, 5, 6]])
        result = DataFrame(List([List([1, 2, 3]), List([4, 5, 6])]))
        tm.assert_frame_equal(result, expected)

    @pytest.mark.parametrize(
        "extension_arr",
        [
            Categorical(list("aabbc")),
            SparseArray([1, np.nan, np.nan, np.nan]),
            IntervalArray([Interval(0, 1), Interval(1, 5)]),
            PeriodArray(pd.period_range(start="1/1/2017", end="1/1/2018", freq="M")),
        ],
    )
    def test_constructor_with_extension_array(self, extension_arr):
        # GH11363
        expected = DataFrame(Series(extension_arr))
        result = DataFrame(extension_arr)
        tm.assert_frame_equal(result, expected)

    def test_datetime_date_tuple_columns_from_dict(self):
        # GH 10863
        v = date.today()
        tup = v, v
        result = DataFrame({tup: Series(range(3), index=range(3))}, columns=[tup])
        expected = DataFrame([0, 1, 2], columns=Index(Series([tup])))
        tm.assert_frame_equal(result, expected)

    def test_construct_with_two_categoricalindex_series(self):
        # GH 14600
        s1 = Series([39, 6, 4], index=CategoricalIndex(["female", "male", "unknown"]))
        s2 = Series(
            [2, 152, 2, 242, 150],
            index=CategoricalIndex(["f", "female", "m", "male", "unknown"]),
        )
        result = DataFrame([s1, s2])
        expected = DataFrame(
            np.array([[39, 6, 4, np.nan, np.nan], [152.0, 242.0, 150.0, 2.0, 2.0]]),
            columns=["female", "male", "unknown", "f", "m"],
        )
        tm.assert_frame_equal(result, expected)

    def test_constructor_series_nonexact_categoricalindex(self):
        # GH 42424
        ser = Series(range(0, 100))
        ser1 = cut(ser, 10).value_counts().head(5)
        ser2 = cut(ser, 10).value_counts().tail(5)
        result = DataFrame({"1": ser1, "2": ser2})
        index = CategoricalIndex(
            [
                Interval(-0.099, 9.9, closed="right"),
                Interval(9.9, 19.8, closed="right"),
                Interval(19.8, 29.7, closed="right"),
                Interval(29.7, 39.6, closed="right"),
                Interval(39.6, 49.5, closed="right"),
                Interval(49.5, 59.4, closed="right"),
                Interval(59.4, 69.3, closed="right"),
                Interval(69.3, 79.2, closed="right"),
                Interval(79.2, 89.1, closed="right"),
                Interval(89.1, 99, closed="right"),
            ],
            ordered=True,
        )
        expected = DataFrame(
            {"1": [10] * 5 + [np.nan] * 5, "2": [np.nan] * 5 + [10] * 5}, index=index
        )
        tm.assert_frame_equal(expected, result)

    def test_from_M8_structured(self):
        dates = [(datetime(2012, 9, 9, 0, 0), datetime(2012, 9, 8, 15, 10))]
        arr = np.array(dates, dtype=[("Date", "M8[us]"), ("Forecasting", "M8[us]")])
        df = DataFrame(arr)

        assert df["Date"][0] == dates[0][0]
        assert df["Forecasting"][0] == dates[0][1]

        s = Series(arr["Date"])
        assert isinstance(s[0], Timestamp)
        assert s[0] == dates[0][0]

    def test_from_datetime_subclass(self):
        # GH21142 Verify whether Datetime subclasses are also of dtype datetime
        class DatetimeSubclass(datetime):
            pass

        data = DataFrame({"datetime": [DatetimeSubclass(2020, 1, 1, 1, 1)]})
        assert data.datetime.dtype == "datetime64[ns]"

    def test_with_mismatched_index_length_raises(self):
        # GH#33437
        dti = date_range("2016-01-01", periods=3, tz="US/Pacific")
        msg = "Shape of passed values|Passed arrays should have the same length"
        with pytest.raises(ValueError, match=msg):
            DataFrame(dti, index=range(4))

    def test_frame_ctor_datetime64_column(self):
        rng = date_range("1/1/2000 00:00:00", "1/1/2000 1:59:50", freq="10s")
        dates = np.asarray(rng)

        df = DataFrame({"A": np.random.randn(len(rng)), "B": dates})
        assert np.issubdtype(df["B"].dtype, np.dtype("M8[ns]"))

    def test_dataframe_constructor_infer_multiindex(self):
        index_lists = [["a", "a", "b", "b"], ["x", "y", "x", "y"]]

        multi = DataFrame(
            np.random.randn(4, 4),
            index=[np.array(x) for x in index_lists],
        )
        assert isinstance(multi.index, MultiIndex)
        assert not isinstance(multi.columns, MultiIndex)

        multi = DataFrame(np.random.randn(4, 4), columns=index_lists)
        assert isinstance(multi.columns, MultiIndex)

    @pytest.mark.parametrize(
        "input_vals",
        [
            ([1, 2]),
            (["1", "2"]),
            (list(date_range("1/1/2011", periods=2, freq="H"))),
            (list(date_range("1/1/2011", periods=2, freq="H", tz="US/Eastern"))),
            ([Interval(left=0, right=5)]),
        ],
    )
    def test_constructor_list_str(self, input_vals, string_dtype):
        # GH#16605
        # Ensure that data elements are converted to strings when
        # dtype is str, 'str', or 'U'

        result = DataFrame({"A": input_vals}, dtype=string_dtype)
        expected = DataFrame({"A": input_vals}).astype({"A": string_dtype})
        tm.assert_frame_equal(result, expected)

    def test_constructor_list_str_na(self, string_dtype):

        result = DataFrame({"A": [1.0, 2.0, None]}, dtype=string_dtype)
        expected = DataFrame({"A": ["1.0", "2.0", None]}, dtype=object)
        tm.assert_frame_equal(result, expected)

    @pytest.mark.parametrize("copy", [False, True])
    def test_dict_nocopy(
        self,
        request,
        copy,
        any_numeric_ea_dtype,
        any_numpy_dtype,
        using_array_manager,
        using_copy_on_write,
    ):
        if (
            using_array_manager
            and not copy
            and any_numpy_dtype not in tm.STRING_DTYPES + tm.BYTES_DTYPES
        ):
            # TODO(ArrayManager) properly honor copy keyword for dict input
            td.mark_array_manager_not_yet_implemented(request)

        a = np.array([1, 2], dtype=any_numpy_dtype)
        b = np.array([3, 4], dtype=any_numpy_dtype)
        if b.dtype.kind in ["S", "U"]:
            # These get cast, making the checks below more cumbersome
            return

        c = pd.array([1, 2], dtype=any_numeric_ea_dtype)
        c_orig = c.copy()
        df = DataFrame({"a": a, "b": b, "c": c}, copy=copy)

        def get_base(obj):
            if isinstance(obj, np.ndarray):
                return obj.base
            elif isinstance(obj.dtype, np.dtype):
                # i.e. DatetimeArray, TimedeltaArray
                return obj._ndarray.base
            else:
                raise TypeError

        def check_views(c_only: bool = False):
            # written to work for either BlockManager or ArrayManager

            # Check that the underlying data behind df["c"] is still `c`
            #  after setting with iloc.  Since we don't know which entry in
            #  df._mgr.arrays corresponds to df["c"], we just check that exactly
            #  one of these arrays is `c`.  GH#38939
            assert sum(x is c for x in df._mgr.arrays) == 1
            if c_only:
                # If we ever stop consolidating in setitem_with_indexer,
                #  this will become unnecessary.
                return

            assert (
                sum(
                    get_base(x) is a
                    for x in df._mgr.arrays
                    if isinstance(x.dtype, np.dtype)
                )
                == 1
            )
            assert (
                sum(
                    get_base(x) is b
                    for x in df._mgr.arrays
                    if isinstance(x.dtype, np.dtype)
                )
                == 1
            )

        if not copy:
            # constructor preserves views
            check_views()

        # TODO: most of the rest of this test belongs in indexing tests
        df.iloc[0, 0] = 0
        df.iloc[0, 1] = 0
        if not copy:
            check_views(True)

        # FIXME(GH#35417): until GH#35417, iloc.setitem into EA values does not preserve
        #  view, so we have to check in the other direction
        df.iloc[:, 2] = pd.array([45, 46], dtype=c.dtype)
        assert df.dtypes.iloc[2] == c.dtype
        if not copy and not using_copy_on_write:
            check_views(True)

        if copy:
            if a.dtype.kind == "M":
                assert a[0] == a.dtype.type(1, "ns")
                assert b[0] == b.dtype.type(3, "ns")
            else:
                assert a[0] == a.dtype.type(1)
                assert b[0] == b.dtype.type(3)
            # FIXME(GH#35417): enable after GH#35417
            assert c[0] == c_orig[0]  # i.e. df.iloc[0, 2]=45 did *not* update c
        elif not using_copy_on_write:
            # TODO: we can call check_views if we stop consolidating
            #  in setitem_with_indexer
            assert c[0] == 45  # i.e. df.iloc[0, 2]=45 *did* update c
            # TODO: we can check b[0] == 0 if we stop consolidating in
            #  setitem_with_indexer (except for datetimelike?)

    def test_from_series_with_name_with_columns(self):
        # GH 7893
        result = DataFrame(Series(1, name="foo"), columns=["bar"])
        expected = DataFrame(columns=["bar"])
        tm.assert_frame_equal(result, expected)

    def test_nested_list_columns(self):
        # GH 14467
        result = DataFrame(
            [[1, 2, 3], [4, 5, 6]], columns=[["A", "A", "A"], ["a", "b", "c"]]
        )
        expected = DataFrame(
            [[1, 2, 3], [4, 5, 6]],
            columns=MultiIndex.from_tuples([("A", "a"), ("A", "b"), ("A", "c")]),
        )
        tm.assert_frame_equal(result, expected)

    def test_from_2d_object_array_of_periods_or_intervals(self):
        # Period analogue to GH#26825
        pi = pd.period_range("2016-04-05", periods=3)
        data = pi._data.astype(object).reshape(1, -1)
        df = DataFrame(data)
        assert df.shape == (1, 3)
        assert (df.dtypes == pi.dtype).all()
        assert (df == pi).all().all()

        ii = pd.IntervalIndex.from_breaks([3, 4, 5, 6])
        data2 = ii._data.astype(object).reshape(1, -1)
        df2 = DataFrame(data2)
        assert df2.shape == (1, 3)
        assert (df2.dtypes == ii.dtype).all()
        assert (df2 == ii).all().all()

        # mixed
        data3 = np.r_[data, data2, data, data2].T
        df3 = DataFrame(data3)
        expected = DataFrame({0: pi, 1: ii, 2: pi, 3: ii})
        tm.assert_frame_equal(df3, expected)

    @pytest.mark.parametrize(
        "col_a, col_b",
        [
            ([[1], [2]], np.array([[1], [2]])),
            (np.array([[1], [2]]), [[1], [2]]),
            (np.array([[1], [2]]), np.array([[1], [2]])),
        ],
    )
    def test_error_from_2darray(self, col_a, col_b):
        msg = "Per-column arrays must each be 1-dimensional"
        with pytest.raises(ValueError, match=msg):
            DataFrame({"a": col_a, "b": col_b})

    def test_from_dict_with_missing_copy_false(self):
        # GH#45369 filled columns should not be views of one another
        df = DataFrame(index=[1, 2, 3], columns=["a", "b", "c"], copy=False)
        assert not np.shares_memory(df["a"]._values, df["b"]._values)

        df.iloc[0, 0] = 0
        expected = DataFrame(
            {
                "a": [0, np.nan, np.nan],
                "b": [np.nan, np.nan, np.nan],
                "c": [np.nan, np.nan, np.nan],
            },
            index=[1, 2, 3],
            dtype=object,
        )
        tm.assert_frame_equal(df, expected)

    def test_construction_empty_array_multi_column_raises(self):
        # GH#46822
        msg = "Empty data passed with indices specified."
        with pytest.raises(ValueError, match=msg):
            DataFrame(data=np.array([]), columns=["a", "b"])


class TestDataFrameConstructorIndexInference:
    def test_frame_from_dict_of_series_overlapping_monthly_period_indexes(self):
        rng1 = pd.period_range("1/1/1999", "1/1/2012", freq="M")
        s1 = Series(np.random.randn(len(rng1)), rng1)

        rng2 = pd.period_range("1/1/1980", "12/1/2001", freq="M")
        s2 = Series(np.random.randn(len(rng2)), rng2)
        df = DataFrame({"s1": s1, "s2": s2})

        exp = pd.period_range("1/1/1980", "1/1/2012", freq="M")
        tm.assert_index_equal(df.index, exp)

    def test_frame_from_dict_with_mixed_tzaware_indexes(self):
        # GH#44091
        dti = date_range("2016-01-01", periods=3)

        ser1 = Series(range(3), index=dti)
        ser2 = Series(range(3), index=dti.tz_localize("UTC"))
        ser3 = Series(range(3), index=dti.tz_localize("US/Central"))
        ser4 = Series(range(3))

        # no tz-naive, but we do have mixed tzs and a non-DTI
        df1 = DataFrame({"A": ser2, "B": ser3, "C": ser4})
        exp_index = Index(
            list(ser2.index) + list(ser3.index) + list(ser4.index), dtype=object
        )
        tm.assert_index_equal(df1.index, exp_index)

        df2 = DataFrame({"A": ser2, "C": ser4, "B": ser3})
        exp_index3 = Index(
            list(ser2.index) + list(ser4.index) + list(ser3.index), dtype=object
        )
        tm.assert_index_equal(df2.index, exp_index3)

        df3 = DataFrame({"B": ser3, "A": ser2, "C": ser4})
        exp_index3 = Index(
            list(ser3.index) + list(ser2.index) + list(ser4.index), dtype=object
        )
        tm.assert_index_equal(df3.index, exp_index3)

        df4 = DataFrame({"C": ser4, "B": ser3, "A": ser2})
        exp_index4 = Index(
            list(ser4.index) + list(ser3.index) + list(ser2.index), dtype=object
        )
        tm.assert_index_equal(df4.index, exp_index4)

        # TODO: not clear if these raising is desired (no extant tests),
        #  but this is de facto behavior 2021-12-22
        msg = "Cannot join tz-naive with tz-aware DatetimeIndex"
        with pytest.raises(TypeError, match=msg):
            DataFrame({"A": ser2, "B": ser3, "C": ser4, "D": ser1})
        with pytest.raises(TypeError, match=msg):
            DataFrame({"A": ser2, "B": ser3, "D": ser1})
        with pytest.raises(TypeError, match=msg):
            DataFrame({"D": ser1, "A": ser2, "B": ser3})


class TestDataFrameConstructorWithDtypeCoercion:
    def test_floating_values_integer_dtype(self):
        # GH#40110 make DataFrame behavior with arraylike floating data and
        #  inty dtype match Series behavior

        arr = np.random.randn(10, 5)

        # GH#49599 in 2.0 we raise instead of either
        #  a) silently ignoring dtype and returningfloat (the old Series behavior) or
        #  b) rounding (the old DataFrame behavior)
        msg = "Trying to coerce float values to integers"
        with pytest.raises(ValueError, match=msg):
            DataFrame(arr, dtype="i8")

        df = DataFrame(arr.round(), dtype="i8")
        assert (df.dtypes == "i8").all()

        # with NaNs, we go through a different path with a different warning
        arr[0, 0] = np.nan
        msg = r"Cannot convert non-finite values \(NA or inf\) to integer"
        with pytest.raises(IntCastingNaNError, match=msg):
            DataFrame(arr, dtype="i8")
        with pytest.raises(IntCastingNaNError, match=msg):
            Series(arr[0], dtype="i8")
        # The future (raising) behavior matches what we would get via astype:
        msg = r"Cannot convert non-finite values \(NA or inf\) to integer"
        with pytest.raises(IntCastingNaNError, match=msg):
            DataFrame(arr).astype("i8")
        with pytest.raises(IntCastingNaNError, match=msg):
            Series(arr[0]).astype("i8")


class TestDataFrameConstructorWithDatetimeTZ:
    @pytest.mark.parametrize("tz", ["US/Eastern", "dateutil/US/Eastern"])
    def test_construction_preserves_tzaware_dtypes(self, tz):
        # after GH#7822
        # these retain the timezones on dict construction
        dr = date_range("2011/1/1", "2012/1/1", freq="W-FRI")
        dr_tz = dr.tz_localize(tz)
        df = DataFrame({"A": "foo", "B": dr_tz}, index=dr)
        tz_expected = DatetimeTZDtype("ns", dr_tz.tzinfo)
        assert df["B"].dtype == tz_expected

        # GH#2810 (with timezones)
        datetimes_naive = [ts.to_pydatetime() for ts in dr]
        datetimes_with_tz = [ts.to_pydatetime() for ts in dr_tz]
        df = DataFrame({"dr": dr})
        df["dr_tz"] = dr_tz
        df["datetimes_naive"] = datetimes_naive
        df["datetimes_with_tz"] = datetimes_with_tz
        result = df.dtypes
        expected = Series(
            [
                np.dtype("datetime64[ns]"),
                DatetimeTZDtype(tz=tz),
                np.dtype("datetime64[ns]"),
                DatetimeTZDtype(tz=tz),
            ],
            index=["dr", "dr_tz", "datetimes_naive", "datetimes_with_tz"],
        )
        tm.assert_series_equal(result, expected)

    @pytest.mark.parametrize("pydt", [True, False])
    def test_constructor_data_aware_dtype_naive(self, tz_aware_fixture, pydt):
        # GH#25843, GH#41555, GH#33401
        tz = tz_aware_fixture
        ts = Timestamp("2019", tz=tz)
        if pydt:
            ts = ts.to_pydatetime()

        msg = (
            "Cannot convert timezone-aware data to timezone-naive dtype. "
            r"Use pd.Series\(values\).dt.tz_localize\(None\) instead."
        )
        with pytest.raises(ValueError, match=msg):
            DataFrame({0: [ts]}, dtype="datetime64[ns]")

        msg2 = "Cannot unbox tzaware Timestamp to tznaive dtype"
        with pytest.raises(TypeError, match=msg2):
            DataFrame({0: ts}, index=[0], dtype="datetime64[ns]")

        with pytest.raises(ValueError, match=msg):
            DataFrame([ts], dtype="datetime64[ns]")

        with pytest.raises(ValueError, match=msg):
            DataFrame(np.array([ts], dtype=object), dtype="datetime64[ns]")

        with pytest.raises(TypeError, match=msg2):
            DataFrame(ts, index=[0], columns=[0], dtype="datetime64[ns]")

        with pytest.raises(ValueError, match=msg):
            DataFrame([Series([ts])], dtype="datetime64[ns]")

        with pytest.raises(ValueError, match=msg):
            DataFrame([[ts]], columns=[0], dtype="datetime64[ns]")

    def test_from_dict(self):

        # 8260
        # support datetime64 with tz

        idx = Index(date_range("20130101", periods=3, tz="US/Eastern"), name="foo")
        dr = date_range("20130110", periods=3)

        # construction
        df = DataFrame({"A": idx, "B": dr})
        assert df["A"].dtype, "M8[ns, US/Eastern"
        assert df["A"].name == "A"
        tm.assert_series_equal(df["A"], Series(idx, name="A"))
        tm.assert_series_equal(df["B"], Series(dr, name="B"))

    def test_from_index(self):

        # from index
        idx2 = date_range("20130101", periods=3, tz="US/Eastern", name="foo")
        df2 = DataFrame(idx2)
        tm.assert_series_equal(df2["foo"], Series(idx2, name="foo"))
        df2 = DataFrame(Series(idx2))
        tm.assert_series_equal(df2["foo"], Series(idx2, name="foo"))

        idx2 = date_range("20130101", periods=3, tz="US/Eastern")
        df2 = DataFrame(idx2)
        tm.assert_series_equal(df2[0], Series(idx2, name=0))
        df2 = DataFrame(Series(idx2))
        tm.assert_series_equal(df2[0], Series(idx2, name=0))

    def test_frame_dict_constructor_datetime64_1680(self):
        dr = date_range("1/1/2012", periods=10)
        s = Series(dr, index=dr)

        # it works!
        DataFrame({"a": "foo", "b": s}, index=dr)
        DataFrame({"a": "foo", "b": s.values}, index=dr)

    def test_frame_datetime64_mixed_index_ctor_1681(self):
        dr = date_range("2011/1/1", "2012/1/1", freq="W-FRI")
        ts = Series(dr)

        # it works!
        d = DataFrame({"A": "foo", "B": ts}, index=dr)
        assert d["B"].isna().all()

    def test_frame_timeseries_column(self):
        # GH19157
        dr = date_range(start="20130101T10:00:00", periods=3, freq="T", tz="US/Eastern")
        result = DataFrame(dr, columns=["timestamps"])
        expected = DataFrame(
            {
                "timestamps": [
                    Timestamp("20130101T10:00:00", tz="US/Eastern"),
                    Timestamp("20130101T10:01:00", tz="US/Eastern"),
                    Timestamp("20130101T10:02:00", tz="US/Eastern"),
                ]
            }
        )
        tm.assert_frame_equal(result, expected)

    def test_nested_dict_construction(self):
        # GH22227
        columns = ["Nevada", "Ohio"]
        pop = {
            "Nevada": {2001: 2.4, 2002: 2.9},
            "Ohio": {2000: 1.5, 2001: 1.7, 2002: 3.6},
        }
        result = DataFrame(pop, index=[2001, 2002, 2003], columns=columns)
        expected = DataFrame(
            [(2.4, 1.7), (2.9, 3.6), (np.nan, np.nan)],
            columns=columns,
            index=Index([2001, 2002, 2003]),
        )
        tm.assert_frame_equal(result, expected)

    def test_from_tzaware_object_array(self):
        # GH#26825 2D object array of tzaware timestamps should not raise
        dti = date_range("2016-04-05 04:30", periods=3, tz="UTC")
        data = dti._data.astype(object).reshape(1, -1)
        df = DataFrame(data)
        assert df.shape == (1, 3)
        assert (df.dtypes == dti.dtype).all()
        assert (df == dti).all().all()

    def test_from_tzaware_mixed_object_array(self):
        # GH#26825
        arr = np.array(
            [
                [
                    Timestamp("2013-01-01 00:00:00"),
                    Timestamp("2013-01-02 00:00:00"),
                    Timestamp("2013-01-03 00:00:00"),
                ],
                [
                    Timestamp("2013-01-01 00:00:00-0500", tz="US/Eastern"),
                    pd.NaT,
                    Timestamp("2013-01-03 00:00:00-0500", tz="US/Eastern"),
                ],
                [
                    Timestamp("2013-01-01 00:00:00+0100", tz="CET"),
                    pd.NaT,
                    Timestamp("2013-01-03 00:00:00+0100", tz="CET"),
                ],
            ],
            dtype=object,
        ).T
        res = DataFrame(arr, columns=["A", "B", "C"])

        expected_dtypes = [
            "datetime64[ns]",
            "datetime64[ns, US/Eastern]",
            "datetime64[ns, CET]",
        ]
        assert (res.dtypes == expected_dtypes).all()

    def test_from_2d_ndarray_with_dtype(self):
        # GH#12513
        array_dim2 = np.arange(10).reshape((5, 2))
        df = DataFrame(array_dim2, dtype="datetime64[ns, UTC]")

        expected = DataFrame(array_dim2).astype("datetime64[ns, UTC]")
        tm.assert_frame_equal(df, expected)

    @pytest.mark.parametrize("typ", [set, frozenset])
    def test_construction_from_set_raises(self, typ):
        # https://github.com/pandas-dev/pandas/issues/32582
        values = typ({1, 2, 3})
        msg = f"'{typ.__name__}' type is unordered"
        with pytest.raises(TypeError, match=msg):
            DataFrame({"a": values})

        with pytest.raises(TypeError, match=msg):
            Series(values)

    def test_construction_from_ndarray_datetimelike(self):
        # ensure the underlying arrays are properly wrapped as EA when
        # constructed from 2D ndarray
        arr = np.arange(0, 12, dtype="datetime64[ns]").reshape(4, 3)
        df = DataFrame(arr)
        assert all(isinstance(arr, DatetimeArray) for arr in df._mgr.arrays)

    def test_construction_from_ndarray_with_eadtype_mismatched_columns(self):
        arr = np.random.randn(10, 2)
        dtype = pd.array([2.0]).dtype
        msg = r"len\(arrays\) must match len\(columns\)"
        with pytest.raises(ValueError, match=msg):
            DataFrame(arr, columns=["foo"], dtype=dtype)

        arr2 = pd.array([2.0, 3.0, 4.0])
        with pytest.raises(ValueError, match=msg):
            DataFrame(arr2, columns=["foo", "bar"])

    def test_columns_indexes_raise_on_sets(self):
        # GH 47215
        data = [[1, 2, 3], [4, 5, 6]]
        with pytest.raises(ValueError, match="index cannot be a set"):
            DataFrame(data, index={"a", "b"})
        with pytest.raises(ValueError, match="columns cannot be a set"):
            DataFrame(data, columns={"a", "b", "c"})


def get1(obj):  # TODO: make a helper in tm?
    if isinstance(obj, Series):
        return obj.iloc[0]
    else:
        return obj.iloc[0, 0]


class TestFromScalar:
    @pytest.fixture(params=[list, dict, None])
    def box(self, request):
        return request.param

    @pytest.fixture
    def constructor(self, frame_or_series, box):

        extra = {"index": range(2)}
        if frame_or_series is DataFrame:
            extra["columns"] = ["A"]

        if box is None:
            return functools.partial(frame_or_series, **extra)

        elif box is dict:
            if frame_or_series is Series:
                return lambda x, **kwargs: frame_or_series(
                    {0: x, 1: x}, **extra, **kwargs
                )
            else:
                return lambda x, **kwargs: frame_or_series({"A": x}, **extra, **kwargs)
        else:
            if frame_or_series is Series:
                return lambda x, **kwargs: frame_or_series([x, x], **extra, **kwargs)
            else:
                return lambda x, **kwargs: frame_or_series(
                    {"A": [x, x]}, **extra, **kwargs
                )

    @pytest.mark.parametrize("dtype", ["M8[ns]", "m8[ns]"])
    def test_from_nat_scalar(self, dtype, constructor):
        obj = constructor(pd.NaT, dtype=dtype)
        assert np.all(obj.dtypes == dtype)
        assert np.all(obj.isna())

    def test_from_timedelta_scalar_preserves_nanos(self, constructor):
        td = Timedelta(1)

        obj = constructor(td, dtype="m8[ns]")
        assert get1(obj) == td

    def test_from_timestamp_scalar_preserves_nanos(self, constructor, fixed_now_ts):
        ts = fixed_now_ts + Timedelta(1)

        obj = constructor(ts, dtype="M8[ns]")
        assert get1(obj) == ts

    def test_from_timedelta64_scalar_object(self, constructor):

        td = Timedelta(1)
        td64 = td.to_timedelta64()

        obj = constructor(td64, dtype=object)
        assert isinstance(get1(obj), np.timedelta64)

    @pytest.mark.parametrize("cls", [np.datetime64, np.timedelta64])
    def test_from_scalar_datetimelike_mismatched(self, constructor, cls):
        scalar = cls("NaT", "ns")
        dtype = {np.datetime64: "m8[ns]", np.timedelta64: "M8[ns]"}[cls]

        if cls is np.datetime64:
            msg1 = r"dtype datetime64\[ns\] cannot be converted to timedelta64\[ns\]"
        else:
            msg1 = r"dtype timedelta64\[ns\] cannot be converted to datetime64\[ns\]"
        msg = "|".join(["Cannot cast", msg1])

        with pytest.raises(TypeError, match=msg):
            constructor(scalar, dtype=dtype)

        scalar = cls(4, "ns")
        with pytest.raises(TypeError, match=msg):
            constructor(scalar, dtype=dtype)

    @pytest.mark.xfail(
        reason="Timestamp constructor has been updated to cast dt64 to non-nano, "
        "but DatetimeArray._from_sequence has not"
    )
    @pytest.mark.parametrize("cls", [datetime, np.datetime64])
    def test_from_out_of_bounds_ns_datetime(self, constructor, cls):
        # scalar that won't fit in nanosecond dt64, but will fit in microsecond
        scalar = datetime(9999, 1, 1)
        exp_dtype = "M8[us]"  # pydatetime objects default to this reso
        if cls is np.datetime64:
            scalar = np.datetime64(scalar, "D")
            exp_dtype = "M8[s]"  # closest reso to input
        result = constructor(scalar)

        item = get1(result)
        dtype = result.dtype if isinstance(result, Series) else result.dtypes.iloc[0]

        assert type(item) is Timestamp
        assert item.asm8.dtype == exp_dtype
        assert dtype == exp_dtype

    def test_out_of_s_bounds_datetime64(self, constructor):
        scalar = np.datetime64(np.iinfo(np.int64).max, "D")
        result = constructor(scalar)
        item = get1(result)
        assert type(item) is np.datetime64
        dtype = result.dtype if isinstance(result, Series) else result.dtypes.iloc[0]
        assert dtype == object

    @pytest.mark.xfail(
        reason="TimedeltaArray constructor has been updated to cast td64 to non-nano, "
        "but TimedeltaArray._from_sequence has not"
    )
    @pytest.mark.parametrize("cls", [timedelta, np.timedelta64])
    def test_from_out_of_bounds_ns_timedelta(self, constructor, cls):
        # scalar that won't fit in nanosecond td64, but will fit in microsecond
        scalar = datetime(9999, 1, 1) - datetime(1970, 1, 1)
        exp_dtype = "m8[us]"  # smallest reso that fits
        if cls is np.timedelta64:
            scalar = np.timedelta64(scalar, "D")
            exp_dtype = "m8[s]"  # closest reso to input
        result = constructor(scalar)

        item = get1(result)
        dtype = result.dtype if isinstance(result, Series) else result.dtypes.iloc[0]

        assert type(item) is Timedelta
        assert item.asm8.dtype == exp_dtype
        assert dtype == exp_dtype

    @pytest.mark.parametrize("cls", [np.datetime64, np.timedelta64])
    def test_out_of_s_bounds_timedelta64(self, constructor, cls):
        scalar = cls(np.iinfo(np.int64).max, "D")
        result = constructor(scalar)
        item = get1(result)
        assert type(item) is cls
        dtype = result.dtype if isinstance(result, Series) else result.dtypes.iloc[0]
        assert dtype == object

    def test_tzaware_data_tznaive_dtype(self, constructor, box, frame_or_series):
        tz = "US/Eastern"
        ts = Timestamp("2019", tz=tz)

        if box is None or (frame_or_series is DataFrame and box is dict):
            msg = "Cannot unbox tzaware Timestamp to tznaive dtype"
            err = TypeError
        else:
            msg = (
                "Cannot convert timezone-aware data to timezone-naive dtype. "
                r"Use pd.Series\(values\).dt.tz_localize\(None\) instead."
            )
            err = ValueError

        with pytest.raises(err, match=msg):
            constructor(ts, dtype="M8[ns]")


# TODO: better location for this test?
class TestAllowNonNano:
    # Until 2.0, we do not preserve non-nano dt64/td64 when passed as ndarray,
    #  but do preserve it when passed as DTA/TDA

    @pytest.fixture(params=[True, False])
    def as_td(self, request):
        return request.param

    @pytest.fixture
    def arr(self, as_td):
        values = np.arange(5).astype(np.int64).view("M8[s]")
        if as_td:
            values = values - values[0]
            return TimedeltaArray._simple_new(values, dtype=values.dtype)
        else:
            return DatetimeArray._simple_new(values, dtype=values.dtype)

    def test_index_allow_non_nano(self, arr):
        idx = Index(arr)
        assert idx.dtype == arr.dtype

    def test_dti_tdi_allow_non_nano(self, arr, as_td):
        if as_td:
            idx = pd.TimedeltaIndex(arr)
        else:
            idx = DatetimeIndex(arr)
        assert idx.dtype == arr.dtype

    def test_series_allow_non_nano(self, arr):
        ser = Series(arr)
        assert ser.dtype == arr.dtype

    def test_frame_allow_non_nano(self, arr):
        df = DataFrame(arr)
        assert df.dtypes[0] == arr.dtype

    def test_frame_from_dict_allow_non_nano(self, arr):
        df = DataFrame({0: arr})
        assert df.dtypes[0] == arr.dtype