test_datetime64.py

# -*- coding: utf-8 -*-
# Arithmetic tests for DataFrame/Series/Index/Array classes that should
# behave identically.
# Specifically for datetime64 and datetime64tz dtypes
from datetime import datetime, timedelta
from itertools import product, starmap
import operator
import warnings

import numpy as np
import pytest
import pytz

from pandas._libs.tslibs.conversion import localize_pydatetime
from pandas._libs.tslibs.offsets import shift_months
from pandas.compat.numpy import np_datetime64_compat
from pandas.errors import NullFrequencyError, PerformanceWarning

import pandas as pd
from pandas import (
    DatetimeIndex, NaT, Period, Series, Timedelta, TimedeltaIndex, Timestamp,
    date_range)
from pandas.core.indexes.datetimes import _to_M8
import pandas.util.testing as tm


def assert_all(obj):
    """
    Test helper to call call obj.all() the appropriate number of times on
    a Series or DataFrame.
    """
    if isinstance(obj, pd.DataFrame):
        assert obj.all().all()
    else:
        assert obj.all()


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

class TestDatetime64DataFrameComparison(object):
    @pytest.mark.parametrize('timestamps', [
        [pd.Timestamp('2012-01-01 13:00:00+00:00')] * 2,
        [pd.Timestamp('2012-01-01 13:00:00')] * 2])
    def test_tz_aware_scalar_comparison(self, timestamps):
        # GH#15966
        df = pd.DataFrame({'test': timestamps})
        expected = pd.DataFrame({'test': [False, False]})
        tm.assert_frame_equal(df == -1, expected)

    def test_dt64_nat_comparison(self):
        # GH#22242, GH#22163 DataFrame considered NaT == ts incorrectly
        ts = pd.Timestamp.now()
        df = pd.DataFrame([ts, pd.NaT])
        expected = pd.DataFrame([True, False])

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


class TestDatetime64SeriesComparison(object):
    # TODO: moved from tests.series.test_operators; needs cleanup

    @pytest.mark.parametrize('pair', [
        ([pd.Timestamp('2011-01-01'), NaT, pd.Timestamp('2011-01-03')],
         [NaT, NaT, pd.Timestamp('2011-01-03')]),

        ([pd.Timedelta('1 days'), NaT, pd.Timedelta('3 days')],
         [NaT, NaT, pd.Timedelta('3 days')]),

        ([pd.Period('2011-01', freq='M'), NaT,
          pd.Period('2011-03', freq='M')],
         [NaT, NaT, pd.Period('2011-03', freq='M')]),

    ])
    @pytest.mark.parametrize('reverse', [True, False])
    @pytest.mark.parametrize('box', [Series, pd.Index])
    @pytest.mark.parametrize('dtype', [None, object])
    def test_nat_comparisons(self, dtype, box, reverse, pair):
        l, r = pair
        if reverse:
            # add lhs / rhs switched data
            l, r = r, l

        left = Series(l, dtype=dtype)
        right = box(r, dtype=dtype)
        # Series, Index

        expected = Series([False, False, True])
        tm.assert_series_equal(left == right, expected)

        expected = Series([True, True, False])
        tm.assert_series_equal(left != right, expected)

        expected = Series([False, False, False])
        tm.assert_series_equal(left < right, expected)

        expected = Series([False, False, False])
        tm.assert_series_equal(left > right, expected)

        expected = Series([False, False, True])
        tm.assert_series_equal(left >= right, expected)

        expected = Series([False, False, True])
        tm.assert_series_equal(left <= right, expected)

    def test_comparison_invalid(self, box_with_array):
        # GH#4968
        # invalid date/int comparisons
        xbox = box_with_array if box_with_array is not pd.Index else np.ndarray

        ser = Series(range(5))
        ser2 = Series(pd.date_range('20010101', periods=5))

        ser = tm.box_expected(ser, box_with_array)
        ser2 = tm.box_expected(ser2, box_with_array)

        for (x, y) in [(ser, ser2), (ser2, ser)]:

            result = x == y
            expected = tm.box_expected([False] * 5, xbox)
            tm.assert_equal(result, expected)

            result = x != y
            expected = tm.box_expected([True] * 5, xbox)
            tm.assert_equal(result, expected)
            msg = 'Invalid comparison between'
            with pytest.raises(TypeError, match=msg):
                x >= y
            with pytest.raises(TypeError, match=msg):
                x > y
            with pytest.raises(TypeError, match=msg):
                x < y
            with pytest.raises(TypeError, match=msg):
                x <= y

    @pytest.mark.parametrize('data', [
        [Timestamp('2011-01-01'), NaT, Timestamp('2011-01-03')],
        [Timedelta('1 days'), NaT, Timedelta('3 days')],
        [Period('2011-01', freq='M'), NaT, Period('2011-03', freq='M')]
    ])
    @pytest.mark.parametrize('dtype', [None, object])
    def test_nat_comparisons_scalar(self, dtype, data, box_with_array):
        if box_with_array is tm.to_array and dtype is object:
            # dont bother testing ndarray comparison methods as this fails
            #  on older numpys (since they check object identity)
            return

        xbox = box_with_array if box_with_array is not pd.Index else np.ndarray

        left = Series(data, dtype=dtype)
        left = tm.box_expected(left, box_with_array)

        expected = [False, False, False]
        expected = tm.box_expected(expected, xbox)
        tm.assert_equal(left == NaT, expected)
        tm.assert_equal(NaT == left, expected)

        expected = [True, True, True]
        expected = tm.box_expected(expected, xbox)
        tm.assert_equal(left != NaT, expected)
        tm.assert_equal(NaT != left, expected)

        expected = [False, False, False]
        expected = tm.box_expected(expected, xbox)
        tm.assert_equal(left < NaT, expected)
        tm.assert_equal(NaT > left, expected)
        tm.assert_equal(left <= NaT, expected)
        tm.assert_equal(NaT >= left, expected)

        tm.assert_equal(left > NaT, expected)
        tm.assert_equal(NaT < left, expected)
        tm.assert_equal(left >= NaT, expected)
        tm.assert_equal(NaT <= left, expected)

    def test_series_comparison_scalars(self):
        series = Series(date_range('1/1/2000', periods=10))

        val = datetime(2000, 1, 4)
        result = series > val
        expected = Series([x > val for x in series])
        tm.assert_series_equal(result, expected)

        val = series[5]
        result = series > val
        expected = Series([x > val for x in series])
        tm.assert_series_equal(result, expected)

    def test_dt64_ser_cmp_date_warning(self):
        # https://github.com/pandas-dev/pandas/issues/21359
        # Remove this test and enble invalid test below
        ser = pd.Series(pd.date_range('20010101', periods=10), name='dates')
        date = ser.iloc[0].to_pydatetime().date()

        with tm.assert_produces_warning(FutureWarning) as m:
            result = ser == date
        expected = pd.Series([True] + [False] * 9, name='dates')
        tm.assert_series_equal(result, expected)
        assert "Comparing Series of datetimes " in str(m[0].message)
        assert "will not compare equal" in str(m[0].message)

        with tm.assert_produces_warning(FutureWarning) as m:
            result = ser != date
        tm.assert_series_equal(result, ~expected)
        assert "will not compare equal" in str(m[0].message)

        with tm.assert_produces_warning(FutureWarning) as m:
            result = ser <= date
        tm.assert_series_equal(result, expected)
        assert "a TypeError will be raised" in str(m[0].message)

        with tm.assert_produces_warning(FutureWarning) as m:
            result = ser < date
        tm.assert_series_equal(result, pd.Series([False] * 10, name='dates'))
        assert "a TypeError will be raised" in str(m[0].message)

        with tm.assert_produces_warning(FutureWarning) as m:
            result = ser >= date
        tm.assert_series_equal(result, pd.Series([True] * 10, name='dates'))
        assert "a TypeError will be raised" in str(m[0].message)

        with tm.assert_produces_warning(FutureWarning) as m:
            result = ser > date
        tm.assert_series_equal(result, pd.Series([False] + [True] * 9,
                                                 name='dates'))
        assert "a TypeError will be raised" in str(m[0].message)

    @pytest.mark.skip(reason="GH#21359")
    def test_dt64ser_cmp_date_invalid(self, box_with_array):
        # GH#19800 datetime.date comparison raises to
        # match DatetimeIndex/Timestamp.  This also matches the behavior
        # of stdlib datetime.datetime

        ser = pd.date_range('20010101', periods=10)
        date = ser.iloc[0].to_pydatetime().date()

        ser = tm.box_expected(ser, box_with_array)
        assert not (ser == date).any()
        assert (ser != date).all()
        with pytest.raises(TypeError):
            ser > date
        with pytest.raises(TypeError):
            ser < date
        with pytest.raises(TypeError):
            ser >= date
        with pytest.raises(TypeError):
            ser <= date

    @pytest.mark.parametrize("left,right", [
        ("lt", "gt"),
        ("le", "ge"),
        ("eq", "eq"),
        ("ne", "ne"),
    ])
    def test_timestamp_compare_series(self, left, right):
        # see gh-4982
        # Make sure we can compare Timestamps on the right AND left hand side.
        ser = pd.Series(pd.date_range("20010101", periods=10), name="dates")
        s_nat = ser.copy(deep=True)

        ser[0] = pd.Timestamp("nat")
        ser[3] = pd.Timestamp("nat")

        left_f = getattr(operator, left)
        right_f = getattr(operator, right)

        # No NaT
        expected = left_f(ser, pd.Timestamp("20010109"))
        result = right_f(pd.Timestamp("20010109"), ser)
        tm.assert_series_equal(result, expected)

        # NaT
        expected = left_f(ser, pd.Timestamp("nat"))
        result = right_f(pd.Timestamp("nat"), ser)
        tm.assert_series_equal(result, expected)

        # Compare to Timestamp with series containing NaT
        expected = left_f(s_nat, pd.Timestamp("20010109"))
        result = right_f(pd.Timestamp("20010109"), s_nat)
        tm.assert_series_equal(result, expected)

        # Compare to NaT with series containing NaT
        expected = left_f(s_nat, pd.Timestamp("nat"))
        result = right_f(pd.Timestamp("nat"), s_nat)
        tm.assert_series_equal(result, expected)

    def test_dt64arr_timestamp_equality(self, box_with_array):
        # GH#11034
        xbox = box_with_array if box_with_array is not pd.Index else np.ndarray

        ser = pd.Series([pd.Timestamp('2000-01-29 01:59:00'), 'NaT'])
        ser = tm.box_expected(ser, box_with_array)

        result = ser != ser
        expected = tm.box_expected([False, True], xbox)
        tm.assert_equal(result, expected)

        result = ser != ser[0]
        expected = tm.box_expected([False, True], xbox)
        tm.assert_equal(result, expected)

        result = ser != ser[1]
        expected = tm.box_expected([True, True], xbox)
        tm.assert_equal(result, expected)

        result = ser == ser
        expected = tm.box_expected([True, False], xbox)
        tm.assert_equal(result, expected)

        result = ser == ser[0]
        expected = tm.box_expected([True, False], xbox)
        tm.assert_equal(result, expected)

        result = ser == ser[1]
        expected = tm.box_expected([False, False], xbox)
        tm.assert_equal(result, expected)

    @pytest.mark.parametrize('op', [operator.eq, operator.ne,
                                    operator.gt, operator.ge,
                                    operator.lt, operator.le])
    def test_comparison_tzawareness_compat(self, op):
        # GH#18162
        dr = pd.date_range('2016-01-01', periods=6)
        dz = dr.tz_localize('US/Pacific')

        # Check that there isn't a problem aware-aware and naive-naive do not
        # raise
        naive_series = Series(dr)
        aware_series = Series(dz)
        msg = 'Cannot compare tz-naive and tz-aware'
        with pytest.raises(TypeError, match=msg):
            op(dz, naive_series)
        with pytest.raises(TypeError, match=msg):
            op(dr, aware_series)

        # TODO: implement _assert_tzawareness_compat for the reverse
        # comparison with the Series on the left-hand side


class TestDatetimeIndexComparisons(object):

    # TODO: moved from tests.indexes.test_base; parametrize and de-duplicate
    @pytest.mark.parametrize("op", [
        operator.eq, operator.ne, operator.gt, operator.lt,
        operator.ge, operator.le
    ])
    def test_comparators(self, op):
        index = tm.makeDateIndex(100)
        element = index[len(index) // 2]
        element = _to_M8(element)

        arr = np.array(index)
        arr_result = op(arr, element)
        index_result = op(index, element)

        assert isinstance(index_result, np.ndarray)
        tm.assert_numpy_array_equal(arr_result, index_result)

    @pytest.mark.parametrize('other', [datetime(2016, 1, 1),
                                       Timestamp('2016-01-01'),
                                       np.datetime64('2016-01-01')])
    def test_dti_cmp_datetimelike(self, other, tz_naive_fixture):
        tz = tz_naive_fixture
        dti = pd.date_range('2016-01-01', periods=2, tz=tz)
        if tz is not None:
            if isinstance(other, np.datetime64):
                # no tzaware version available
                return
            other = localize_pydatetime(other, dti.tzinfo)

        result = dti == other
        expected = np.array([True, False])
        tm.assert_numpy_array_equal(result, expected)

        result = dti > other
        expected = np.array([False, True])
        tm.assert_numpy_array_equal(result, expected)

        result = dti >= other
        expected = np.array([True, True])
        tm.assert_numpy_array_equal(result, expected)

        result = dti < other
        expected = np.array([False, False])
        tm.assert_numpy_array_equal(result, expected)

        result = dti <= other
        expected = np.array([True, False])
        tm.assert_numpy_array_equal(result, expected)

    def dt64arr_cmp_non_datetime(self, tz_naive_fixture, box_with_array):
        # GH#19301 by convention datetime.date is not considered comparable
        # to Timestamp or DatetimeIndex.  This may change in the future.
        tz = tz_naive_fixture
        dti = pd.date_range('2016-01-01', periods=2, tz=tz)
        dtarr = tm.box_expected(dti, box_with_array)

        other = datetime(2016, 1, 1).date()
        assert not (dtarr == other).any()
        assert (dtarr != other).all()
        with pytest.raises(TypeError):
            dtarr < other
        with pytest.raises(TypeError):
            dtarr <= other
        with pytest.raises(TypeError):
            dtarr > other
        with pytest.raises(TypeError):
            dtarr >= other

    @pytest.mark.parametrize('other', [None, np.nan, pd.NaT])
    def test_dti_eq_null_scalar(self, other, tz_naive_fixture):
        # GH#19301
        tz = tz_naive_fixture
        dti = pd.date_range('2016-01-01', periods=2, tz=tz)
        assert not (dti == other).any()

    @pytest.mark.parametrize('other', [None, np.nan, pd.NaT])
    def test_dti_ne_null_scalar(self, other, tz_naive_fixture):
        # GH#19301
        tz = tz_naive_fixture
        dti = pd.date_range('2016-01-01', periods=2, tz=tz)
        assert (dti != other).all()

    @pytest.mark.parametrize('other', [None, np.nan])
    def test_dti_cmp_null_scalar_inequality(self, tz_naive_fixture, other,
                                            box_with_array):
        # GH#19301
        tz = tz_naive_fixture
        dti = pd.date_range('2016-01-01', periods=2, tz=tz)
        # FIXME: ValueError with transpose
        dtarr = tm.box_expected(dti, box_with_array, transpose=False)
        msg = 'Invalid comparison between'
        with pytest.raises(TypeError, match=msg):
            dtarr < other
        with pytest.raises(TypeError, match=msg):
            dtarr <= other
        with pytest.raises(TypeError, match=msg):
            dtarr > other
        with pytest.raises(TypeError, match=msg):
            dtarr >= other

    @pytest.mark.parametrize('dtype', [None, object])
    def test_dti_cmp_nat(self, dtype, box_with_array):
        if box_with_array is tm.to_array and dtype is object:
            # dont bother testing ndarray comparison methods as this fails
            #  on older numpys (since they check object identity)
            return

        xbox = box_with_array if box_with_array is not pd.Index else np.ndarray

        left = pd.DatetimeIndex([pd.Timestamp('2011-01-01'), pd.NaT,
                                 pd.Timestamp('2011-01-03')])
        right = pd.DatetimeIndex([pd.NaT, pd.NaT, pd.Timestamp('2011-01-03')])

        left = tm.box_expected(left, box_with_array)
        right = tm.box_expected(right, box_with_array)

        lhs, rhs = left, right
        if dtype is object:
            lhs, rhs = left.astype(object), right.astype(object)

        result = rhs == lhs
        expected = np.array([False, False, True])
        expected = tm.box_expected(expected, xbox)
        tm.assert_equal(result, expected)

        result = lhs != rhs
        expected = np.array([True, True, False])
        expected = tm.box_expected(expected, xbox)
        tm.assert_equal(result, expected)

        expected = np.array([False, False, False])
        expected = tm.box_expected(expected, xbox)
        tm.assert_equal(lhs == pd.NaT, expected)
        tm.assert_equal(pd.NaT == rhs, expected)

        expected = np.array([True, True, True])
        expected = tm.box_expected(expected, xbox)
        tm.assert_equal(lhs != pd.NaT, expected)
        tm.assert_equal(pd.NaT != lhs, expected)

        expected = np.array([False, False, False])
        expected = tm.box_expected(expected, xbox)
        tm.assert_equal(lhs < pd.NaT, expected)
        tm.assert_equal(pd.NaT > lhs, expected)

    def test_dti_cmp_nat_behaves_like_float_cmp_nan(self):
        fidx1 = pd.Index([1.0, np.nan, 3.0, np.nan, 5.0, 7.0])
        fidx2 = pd.Index([2.0, 3.0, np.nan, np.nan, 6.0, 7.0])

        didx1 = pd.DatetimeIndex(['2014-01-01', pd.NaT, '2014-03-01', pd.NaT,
                                  '2014-05-01', '2014-07-01'])
        didx2 = pd.DatetimeIndex(['2014-02-01', '2014-03-01', pd.NaT, pd.NaT,
                                  '2014-06-01', '2014-07-01'])
        darr = np.array([np_datetime64_compat('2014-02-01 00:00Z'),
                         np_datetime64_compat('2014-03-01 00:00Z'),
                         np_datetime64_compat('nat'), np.datetime64('nat'),
                         np_datetime64_compat('2014-06-01 00:00Z'),
                         np_datetime64_compat('2014-07-01 00:00Z')])

        cases = [(fidx1, fidx2), (didx1, didx2), (didx1, darr)]

        # Check pd.NaT is handles as the same as np.nan
        with tm.assert_produces_warning(None):
            for idx1, idx2 in cases:

                result = idx1 < idx2
                expected = np.array([True, False, False, False, True, False])
                tm.assert_numpy_array_equal(result, expected)

                result = idx2 > idx1
                expected = np.array([True, False, False, False, True, False])
                tm.assert_numpy_array_equal(result, expected)

                result = idx1 <= idx2
                expected = np.array([True, False, False, False, True, True])
                tm.assert_numpy_array_equal(result, expected)

                result = idx2 >= idx1
                expected = np.array([True, False, False, False, True, True])
                tm.assert_numpy_array_equal(result, expected)

                result = idx1 == idx2
                expected = np.array([False, False, False, False, False, True])
                tm.assert_numpy_array_equal(result, expected)

                result = idx1 != idx2
                expected = np.array([True, True, True, True, True, False])
                tm.assert_numpy_array_equal(result, expected)

        with tm.assert_produces_warning(None):
            for idx1, val in [(fidx1, np.nan), (didx1, pd.NaT)]:
                result = idx1 < val
                expected = np.array([False, False, False, False, False, False])
                tm.assert_numpy_array_equal(result, expected)
                result = idx1 > val
                tm.assert_numpy_array_equal(result, expected)

                result = idx1 <= val
                tm.assert_numpy_array_equal(result, expected)
                result = idx1 >= val
                tm.assert_numpy_array_equal(result, expected)

                result = idx1 == val
                tm.assert_numpy_array_equal(result, expected)

                result = idx1 != val
                expected = np.array([True, True, True, True, True, True])
                tm.assert_numpy_array_equal(result, expected)

        # Check pd.NaT is handles as the same as np.nan
        with tm.assert_produces_warning(None):
            for idx1, val in [(fidx1, 3), (didx1, datetime(2014, 3, 1))]:
                result = idx1 < val
                expected = np.array([True, False, False, False, False, False])
                tm.assert_numpy_array_equal(result, expected)
                result = idx1 > val
                expected = np.array([False, False, False, False, True, True])
                tm.assert_numpy_array_equal(result, expected)

                result = idx1 <= val
                expected = np.array([True, False, True, False, False, False])
                tm.assert_numpy_array_equal(result, expected)
                result = idx1 >= val
                expected = np.array([False, False, True, False, True, True])
                tm.assert_numpy_array_equal(result, expected)

                result = idx1 == val
                expected = np.array([False, False, True, False, False, False])
                tm.assert_numpy_array_equal(result, expected)

                result = idx1 != val
                expected = np.array([True, True, False, True, True, True])
                tm.assert_numpy_array_equal(result, expected)

    @pytest.mark.parametrize('op', [operator.eq, operator.ne,
                                    operator.gt, operator.ge,
                                    operator.lt, operator.le])
    def test_comparison_tzawareness_compat(self, op, box_with_array):
        # GH#18162
        dr = pd.date_range('2016-01-01', periods=6)
        dz = dr.tz_localize('US/Pacific')

        # FIXME: ValueError with transpose
        dr = tm.box_expected(dr, box_with_array, transpose=False)
        dz = tm.box_expected(dz, box_with_array, transpose=False)

        msg = 'Cannot compare tz-naive and tz-aware'
        with pytest.raises(TypeError, match=msg):
            op(dr, dz)
        if box_with_array is not pd.DataFrame:
            # DataFrame op is invalid until transpose bug is fixed
            with pytest.raises(TypeError, match=msg):
                op(dr, list(dz))
            with pytest.raises(TypeError, match=msg):
                op(dr, np.array(list(dz), dtype=object))

        with pytest.raises(TypeError, match=msg):
            op(dz, dr)
        if box_with_array is not pd.DataFrame:
            # DataFrame op is invalid until transpose bug is fixed
            with pytest.raises(TypeError, match=msg):
                op(dz, list(dr))
            with pytest.raises(TypeError, match=msg):
                op(dz, np.array(list(dr), dtype=object))

        # Check that there isn't a problem aware-aware and naive-naive do not
        # raise
        assert_all(dr == dr)
        assert_all(dz == dz)
        if box_with_array is not pd.DataFrame:
            # DataFrame doesn't align the lists correctly unless we transpose,
            #  which we cannot do at the moment
            assert (dr == list(dr)).all()
            assert (dz == list(dz)).all()

        # Check comparisons against scalar Timestamps
        ts = pd.Timestamp('2000-03-14 01:59')
        ts_tz = pd.Timestamp('2000-03-14 01:59', tz='Europe/Amsterdam')

        assert_all(dr > ts)
        with pytest.raises(TypeError, match=msg):
            op(dr, ts_tz)

        assert_all(dz > ts_tz)
        with pytest.raises(TypeError, match=msg):
            op(dz, ts)

        # GH#12601: Check comparison against Timestamps and DatetimeIndex
        with pytest.raises(TypeError, match=msg):
            op(ts, dz)

    @pytest.mark.parametrize('op', [operator.eq, operator.ne,
                                    operator.gt, operator.ge,
                                    operator.lt, operator.le])
    @pytest.mark.parametrize('other', [datetime(2016, 1, 1),
                                       Timestamp('2016-01-01'),
                                       np.datetime64('2016-01-01')])
    def test_scalar_comparison_tzawareness(self, op, other, tz_aware_fixture,
                                           box_with_array):
        tz = tz_aware_fixture
        dti = pd.date_range('2016-01-01', periods=2, tz=tz)

        # FIXME: ValueError with transpose
        dtarr = tm.box_expected(dti, box_with_array, transpose=False)
        msg = 'Cannot compare tz-naive and tz-aware'
        with pytest.raises(TypeError, match=msg):
            op(dtarr, other)
        with pytest.raises(TypeError, match=msg):
            op(other, dtarr)

    @pytest.mark.parametrize('op', [operator.eq, operator.ne,
                                    operator.gt, operator.ge,
                                    operator.lt, operator.le])
    def test_nat_comparison_tzawareness(self, op):
        # GH#19276
        # tzaware DatetimeIndex should not raise when compared to NaT
        dti = pd.DatetimeIndex(['2014-01-01', pd.NaT, '2014-03-01', pd.NaT,
                                '2014-05-01', '2014-07-01'])
        expected = np.array([op == operator.ne] * len(dti))
        result = op(dti, pd.NaT)
        tm.assert_numpy_array_equal(result, expected)

        result = op(dti.tz_localize('US/Pacific'), pd.NaT)
        tm.assert_numpy_array_equal(result, expected)

    def test_dti_cmp_str(self, tz_naive_fixture):
        # GH#22074
        # regardless of tz, we expect these comparisons are valid
        tz = tz_naive_fixture
        rng = date_range('1/1/2000', periods=10, tz=tz)
        other = '1/1/2000'

        result = rng == other
        expected = np.array([True] + [False] * 9)
        tm.assert_numpy_array_equal(result, expected)

        result = rng != other
        expected = np.array([False] + [True] * 9)
        tm.assert_numpy_array_equal(result, expected)

        result = rng < other
        expected = np.array([False] * 10)
        tm.assert_numpy_array_equal(result, expected)

        result = rng <= other
        expected = np.array([True] + [False] * 9)
        tm.assert_numpy_array_equal(result, expected)

        result = rng > other
        expected = np.array([False] + [True] * 9)
        tm.assert_numpy_array_equal(result, expected)

        result = rng >= other
        expected = np.array([True] * 10)
        tm.assert_numpy_array_equal(result, expected)

    @pytest.mark.parametrize('other', ['foo', 99, 4.0,
                                       object(), timedelta(days=2)])
    def test_dt64arr_cmp_scalar_invalid(self, other, tz_naive_fixture,
                                        box_with_array):
        # GH#22074
        tz = tz_naive_fixture
        xbox = box_with_array if box_with_array is not pd.Index else np.ndarray

        rng = date_range('1/1/2000', periods=10, tz=tz)
        # FIXME: ValueError with transpose
        rng = tm.box_expected(rng, box_with_array, transpose=False)

        result = rng == other
        expected = np.array([False] * 10)
        expected = tm.box_expected(expected, xbox, transpose=False)
        tm.assert_equal(result, expected)

        result = rng != other
        expected = np.array([True] * 10)
        expected = tm.box_expected(expected, xbox, transpose=False)
        tm.assert_equal(result, expected)
        msg = 'Invalid comparison between'
        with pytest.raises(TypeError, match=msg):
            rng < other
        with pytest.raises(TypeError, match=msg):
            rng <= other
        with pytest.raises(TypeError, match=msg):
            rng > other
        with pytest.raises(TypeError, match=msg):
            rng >= other

    def test_dti_cmp_list(self):
        rng = date_range('1/1/2000', periods=10)

        result = rng == list(rng)
        expected = rng == rng
        tm.assert_numpy_array_equal(result, expected)

    @pytest.mark.parametrize('other', [
        pd.timedelta_range('1D', periods=10),
        pd.timedelta_range('1D', periods=10).to_series(),
        pd.timedelta_range('1D', periods=10).asi8.view('m8[ns]')
    ], ids=lambda x: type(x).__name__)
    def test_dti_cmp_tdi_tzawareness(self, other):
        # GH#22074
        # reversion test that we _don't_ call _assert_tzawareness_compat
        # when comparing against TimedeltaIndex
        dti = date_range('2000-01-01', periods=10, tz='Asia/Tokyo')

        result = dti == other
        expected = np.array([False] * 10)
        tm.assert_numpy_array_equal(result, expected)

        result = dti != other
        expected = np.array([True] * 10)
        tm.assert_numpy_array_equal(result, expected)
        msg = 'Invalid comparison between'
        with pytest.raises(TypeError, match=msg):
            dti < other
        with pytest.raises(TypeError, match=msg):
            dti <= other
        with pytest.raises(TypeError, match=msg):
            dti > other
        with pytest.raises(TypeError, match=msg):
            dti >= other

    def test_dti_cmp_object_dtype(self):
        # GH#22074
        dti = date_range('2000-01-01', periods=10, tz='Asia/Tokyo')

        other = dti.astype('O')

        result = dti == other
        expected = np.array([True] * 10)
        tm.assert_numpy_array_equal(result, expected)

        other = dti.tz_localize(None)
        msg = 'Cannot compare tz-naive and tz-aware'
        with pytest.raises(TypeError, match=msg):
            # tzawareness failure
            dti != other

        other = np.array(list(dti[:5]) + [Timedelta(days=1)] * 5)
        result = dti == other
        expected = np.array([True] * 5 + [False] * 5)
        tm.assert_numpy_array_equal(result, expected)
        msg = "Cannot compare type"
        with pytest.raises(TypeError, match=msg):
            dti >= other


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

class TestDatetime64Arithmetic(object):
    # This class is intended for "finished" tests that are fully parametrized
    #  over DataFrame/Series/Index/DatetimeArray

    # -------------------------------------------------------------
    # Addition/Subtraction of timedelta-like

    def test_dt64arr_add_timedeltalike_scalar(self, tz_naive_fixture,
                                              two_hours, box_with_array):
        # GH#22005, GH#22163 check DataFrame doesn't raise TypeError
        tz = tz_naive_fixture

        rng = pd.date_range('2000-01-01', '2000-02-01', tz=tz)
        expected = pd.date_range('2000-01-01 02:00',
                                 '2000-02-01 02:00', tz=tz)

        # FIXME: calling with transpose=True raises ValueError
        rng = tm.box_expected(rng, box_with_array, transpose=False)
        expected = tm.box_expected(expected, box_with_array, transpose=False)

        result = rng + two_hours
        tm.assert_equal(result, expected)

    def test_dt64arr_iadd_timedeltalike_scalar(self, tz_naive_fixture,
                                               two_hours, box_with_array):
        tz = tz_naive_fixture

        rng = pd.date_range('2000-01-01', '2000-02-01', tz=tz)
        expected = pd.date_range('2000-01-01 02:00',
                                 '2000-02-01 02:00', tz=tz)

        # FIXME: calling with transpose=True raises ValueError
        rng = tm.box_expected(rng, box_with_array, transpose=False)
        expected = tm.box_expected(expected, box_with_array, transpose=False)

        rng += two_hours
        tm.assert_equal(rng, expected)

    def test_dt64arr_sub_timedeltalike_scalar(self, tz_naive_fixture,
                                              two_hours, box_with_array):
        tz = tz_naive_fixture

        rng = pd.date_range('2000-01-01', '2000-02-01', tz=tz)
        expected = pd.date_range('1999-12-31 22:00',
                                 '2000-01-31 22:00', tz=tz)

        # FIXME: calling with transpose=True raises ValueError
        rng = tm.box_expected(rng, box_with_array, transpose=False)
        expected = tm.box_expected(expected, box_with_array, transpose=False)

        result = rng - two_hours
        tm.assert_equal(result, expected)

    def test_dt64arr_isub_timedeltalike_scalar(self, tz_naive_fixture,
                                               two_hours, box_with_array):
        tz = tz_naive_fixture

        rng = pd.date_range('2000-01-01', '2000-02-01', tz=tz)
        expected = pd.date_range('1999-12-31 22:00',
                                 '2000-01-31 22:00', tz=tz)

        # FIXME: calling with transpose=True raises ValueError
        rng = tm.box_expected(rng, box_with_array, transpose=False)
        expected = tm.box_expected(expected, box_with_array, transpose=False)

        rng -= two_hours
        tm.assert_equal(rng, expected)

    def test_dt64arr_add_td64_scalar(self, box_with_array):
        # scalar timedeltas/np.timedelta64 objects
        # operate with np.timedelta64 correctly
        ser = Series([Timestamp('20130101 9:01'), Timestamp('20130101 9:02')])

        expected = Series([Timestamp('20130101 9:01:01'),
                           Timestamp('20130101 9:02:01')])

        dtarr = tm.box_expected(ser, box_with_array)
        expected = tm.box_expected(expected, box_with_array)

        result = dtarr + np.timedelta64(1, 's')
        tm.assert_equal(result, expected)
        result = np.timedelta64(1, 's') + dtarr
        tm.assert_equal(result, expected)

        expected = Series([Timestamp('20130101 9:01:00.005'),
                           Timestamp('20130101 9:02:00.005')])
        expected = tm.box_expected(expected, box_with_array)

        result = dtarr + np.timedelta64(5, 'ms')
        tm.assert_equal(result, expected)
        result = np.timedelta64(5, 'ms') + dtarr
        tm.assert_equal(result, expected)

    def test_dt64arr_add_sub_td64_nat(self, box_with_array, tz_naive_fixture):
        # GH#23320 special handling for timedelta64("NaT")
        tz = tz_naive_fixture

        dti = pd.date_range("1994-04-01", periods=9, tz=tz, freq="QS")
        other = np.timedelta64("NaT")
        expected = pd.DatetimeIndex(["NaT"] * 9, tz=tz)

        # FIXME: fails with transpose=True due to tz-aware DataFrame
        #  transpose bug
        obj = tm.box_expected(dti, box_with_array, transpose=False)
        expected = tm.box_expected(expected, box_with_array, transpose=False)

        result = obj + other
        tm.assert_equal(result, expected)
        result = other + obj
        tm.assert_equal(result, expected)
        result = obj - other
        tm.assert_equal(result, expected)
        msg = 'cannot subtract'
        with pytest.raises(TypeError, match=msg):
            other - obj

    def test_dt64arr_add_sub_td64ndarray(self, tz_naive_fixture,
                                         box_with_array):
        if box_with_array is pd.DataFrame:
            pytest.xfail("FIXME: ValueError with transpose; "
                         "alignment error without")

        tz = tz_naive_fixture
        dti = pd.date_range('2016-01-01', periods=3, tz=tz)
        tdi = pd.TimedeltaIndex(['-1 Day', '-1 Day', '-1 Day'])
        tdarr = tdi.values

        expected = pd.date_range('2015-12-31', periods=3, tz=tz)

        dtarr = tm.box_expected(dti, box_with_array)
        expected = tm.box_expected(expected, box_with_array)

        result = dtarr + tdarr
        tm.assert_equal(result, expected)
        result = tdarr + dtarr
        tm.assert_equal(result, expected)

        expected = pd.date_range('2016-01-02', periods=3, tz=tz)
        expected = tm.box_expected(expected, box_with_array)

        result = dtarr - tdarr
        tm.assert_equal(result, expected)
        msg = 'cannot subtract'
        with pytest.raises(TypeError, match=msg):
            tdarr - dtarr

    # -----------------------------------------------------------------
    # Subtraction of datetime-like scalars

    @pytest.mark.parametrize('ts', [
        pd.Timestamp('2013-01-01'),
        pd.Timestamp('2013-01-01').to_pydatetime(),
        pd.Timestamp('2013-01-01').to_datetime64()])
    def test_dt64arr_sub_dtscalar(self, box_with_array, ts):
        # GH#8554, GH#22163 DataFrame op should _not_ return dt64 dtype
        idx = pd.date_range('2013-01-01', periods=3)
        idx = tm.box_expected(idx, box_with_array)

        expected = pd.TimedeltaIndex(['0 Days', '1 Day', '2 Days'])
        expected = tm.box_expected(expected, box_with_array)

        result = idx - ts
        tm.assert_equal(result, expected)

    def test_dt64arr_sub_datetime64_not_ns(self, box_with_array):
        # GH#7996, GH#22163 ensure non-nano datetime64 is converted to nano
        #  for DataFrame operation
        dt64 = np.datetime64('2013-01-01')
        assert dt64.dtype == 'datetime64[D]'

        dti = pd.date_range('20130101', periods=3)
        dtarr = tm.box_expected(dti, box_with_array)

        expected = pd.TimedeltaIndex(['0 Days', '1 Day', '2 Days'])
        expected = tm.box_expected(expected, box_with_array)

        result = dtarr - dt64
        tm.assert_equal(result, expected)

        result = dt64 - dtarr
        tm.assert_equal(result, -expected)

    def test_dt64arr_sub_timestamp(self, box_with_array):
        ser = pd.date_range('2014-03-17', periods=2, freq='D',
                            tz='US/Eastern')
        ts = ser[0]

        # FIXME: transpose raises ValueError
        ser = tm.box_expected(ser, box_with_array, transpose=False)

        delta_series = pd.Series([np.timedelta64(0, 'D'),
                                  np.timedelta64(1, 'D')])
        expected = tm.box_expected(delta_series, box_with_array,
                                   transpose=False)

        tm.assert_equal(ser - ts, expected)
        tm.assert_equal(ts - ser, -expected)

    def test_dt64arr_sub_NaT(self, box_with_array):
        # GH#18808
        dti = pd.DatetimeIndex([pd.NaT, pd.Timestamp('19900315')])
        ser = tm.box_expected(dti, box_with_array, transpose=False)

        result = ser - pd.NaT
        expected = pd.Series([pd.NaT, pd.NaT], dtype='timedelta64[ns]')
        # FIXME: raises ValueError with transpose
        expected = tm.box_expected(expected, box_with_array, transpose=False)
        tm.assert_equal(result, expected)

        dti_tz = dti.tz_localize('Asia/Tokyo')
        ser_tz = tm.box_expected(dti_tz, box_with_array, transpose=False)

        result = ser_tz - pd.NaT
        expected = pd.Series([pd.NaT, pd.NaT], dtype='timedelta64[ns]')
        expected = tm.box_expected(expected, box_with_array, transpose=False)
        tm.assert_equal(result, expected)

    # -------------------------------------------------------------
    # Subtraction of datetime-like array-like

    def test_dt64arr_naive_sub_dt64ndarray(self, box_with_array):
        dti = pd.date_range('2016-01-01', periods=3, tz=None)
        dt64vals = dti.values

        dtarr = tm.box_expected(dti, box_with_array)

        expected = dtarr - dtarr
        result = dtarr - dt64vals
        tm.assert_equal(result, expected)
        result = dt64vals - dtarr
        tm.assert_equal(result, expected)

    def test_dt64arr_aware_sub_dt64ndarray_raises(self, tz_aware_fixture,
                                                  box_with_array):
        if box_with_array is pd.DataFrame:
            pytest.xfail("FIXME: ValueError with transpose; "
                         "alignment error without")

        tz = tz_aware_fixture
        dti = pd.date_range('2016-01-01', periods=3, tz=tz)
        dt64vals = dti.values

        dtarr = tm.box_expected(dti, box_with_array)
        msg = 'DatetimeArray subtraction must have the same timezones or'
        with pytest.raises(TypeError, match=msg):
            dtarr - dt64vals
        with pytest.raises(TypeError, match=msg):
            dt64vals - dtarr

    # -------------------------------------------------------------
    # Addition of datetime-like others (invalid)

    def test_dt64arr_add_dt64ndarray_raises(self, tz_naive_fixture,
                                            box_with_array):
        if box_with_array is pd.DataFrame:
            pytest.xfail("FIXME: ValueError with transpose; "
                         "alignment error without")

        tz = tz_naive_fixture
        dti = pd.date_range('2016-01-01', periods=3, tz=tz)
        dt64vals = dti.values

        dtarr = tm.box_expected(dti, box_with_array)
        msg = 'cannot add'
        with pytest.raises(TypeError, match=msg):
            dtarr + dt64vals
        with pytest.raises(TypeError, match=msg):
            dt64vals + dtarr

    def test_dt64arr_add_timestamp_raises(self, box_with_array):
        # GH#22163 ensure DataFrame doesn't cast Timestamp to i8
        idx = DatetimeIndex(['2011-01-01', '2011-01-02'])
        idx = tm.box_expected(idx, box_with_array)
        msg = 'cannot add'
        with pytest.raises(TypeError, match=msg):
            idx + Timestamp('2011-01-01')
        with pytest.raises(TypeError, match=msg):
            Timestamp('2011-01-01') + idx

    # -------------------------------------------------------------
    # Other Invalid Addition/Subtraction

    @pytest.mark.parametrize('other', [3.14, np.array([2.0, 3.0])])
    def test_dt64arr_add_sub_float(self, other, box_with_array):
        dti = DatetimeIndex(['2011-01-01', '2011-01-02'], freq='D')
        dtarr = tm.box_expected(dti, box_with_array)
        msg = '|'.join(['unsupported operand type', 'cannot (add|subtract)'])
        with pytest.raises(TypeError, match=msg):
            dtarr + other
        with pytest.raises(TypeError, match=msg):
            other + dtarr
        with pytest.raises(TypeError, match=msg):
            dtarr - other
        with pytest.raises(TypeError, match=msg):
            other - dtarr

    @pytest.mark.parametrize('pi_freq', ['D', 'W', 'Q', 'H'])
    @pytest.mark.parametrize('dti_freq', [None, 'D'])
    def test_dt64arr_add_sub_parr(self, dti_freq, pi_freq,
                                  box_with_array, box_with_array2):
        # GH#20049 subtracting PeriodIndex should raise TypeError
        dti = pd.DatetimeIndex(['2011-01-01', '2011-01-02'], freq=dti_freq)
        pi = dti.to_period(pi_freq)

        dtarr = tm.box_expected(dti, box_with_array)
        parr = tm.box_expected(pi, box_with_array2)
        msg = '|'.join(['cannot (add|subtract)', 'unsupported operand',
                        'descriptor.*requires', 'ufunc.*cannot use operands'])
        with pytest.raises(TypeError, match=msg):
            dtarr + parr
        with pytest.raises(TypeError, match=msg):
            parr + dtarr
        with pytest.raises(TypeError, match=msg):
            dtarr - parr
        with pytest.raises(TypeError, match=msg):
            parr - dtarr

    @pytest.mark.parametrize('dti_freq', [None, 'D'])
    def test_dt64arr_add_sub_period_scalar(self, dti_freq, box_with_array):
        # GH#13078
        # not supported, check TypeError
        per = pd.Period('2011-01-01', freq='D')

        idx = pd.DatetimeIndex(['2011-01-01', '2011-01-02'], freq=dti_freq)
        dtarr = tm.box_expected(idx, box_with_array)
        msg = '|'.join(['unsupported operand type', 'cannot (add|subtract)'])
        with pytest.raises(TypeError, match=msg):
            dtarr + per
        with pytest.raises(TypeError, match=msg):
            per + dtarr
        with pytest.raises(TypeError, match=msg):
            dtarr - per
        with pytest.raises(TypeError, match=msg):
            per - dtarr


class TestDatetime64DateOffsetArithmetic(object):

    # -------------------------------------------------------------
    # Tick DateOffsets

    # TODO: parametrize over timezone?
    def test_dt64arr_series_add_tick_DateOffset(self, box_with_array):
        # GH#4532
        # operate with pd.offsets
        ser = Series([Timestamp('20130101 9:01'), Timestamp('20130101 9:02')])
        expected = Series([Timestamp('20130101 9:01:05'),
                           Timestamp('20130101 9:02:05')])

        ser = tm.box_expected(ser, box_with_array)
        expected = tm.box_expected(expected, box_with_array)

        result = ser + pd.offsets.Second(5)
        tm.assert_equal(result, expected)

        result2 = pd.offsets.Second(5) + ser
        tm.assert_equal(result2, expected)

    def test_dt64arr_series_sub_tick_DateOffset(self, box_with_array):
        # GH#4532
        # operate with pd.offsets
        ser = Series([Timestamp('20130101 9:01'), Timestamp('20130101 9:02')])
        expected = Series([Timestamp('20130101 9:00:55'),
                           Timestamp('20130101 9:01:55')])

        ser = tm.box_expected(ser, box_with_array)
        expected = tm.box_expected(expected, box_with_array)

        result = ser - pd.offsets.Second(5)
        tm.assert_equal(result, expected)

        result2 = -pd.offsets.Second(5) + ser
        tm.assert_equal(result2, expected)
        msg = "bad operand type for unary"
        with pytest.raises(TypeError, match=msg):
            pd.offsets.Second(5) - ser

    @pytest.mark.parametrize('cls_name', ['Day', 'Hour', 'Minute', 'Second',
                                          'Milli', 'Micro', 'Nano'])
    def test_dt64arr_add_sub_tick_DateOffset_smoke(self, cls_name,
                                                   box_with_array):
        # GH#4532
        # smoke tests for valid DateOffsets
        ser = Series([Timestamp('20130101 9:01'), Timestamp('20130101 9:02')])
        ser = tm.box_expected(ser, box_with_array)

        offset_cls = getattr(pd.offsets, cls_name)
        ser + offset_cls(5)
        offset_cls(5) + ser
        ser - offset_cls(5)

    def test_dti_add_tick_tzaware(self, tz_aware_fixture, box_with_array):
        # GH#21610, GH#22163 ensure DataFrame doesn't return object-dtype
        tz = tz_aware_fixture
        if tz == 'US/Pacific':
            dates = date_range('2012-11-01', periods=3, tz=tz)
            offset = dates + pd.offsets.Hour(5)
            assert dates[0] + pd.offsets.Hour(5) == offset[0]

        dates = date_range('2010-11-01 00:00',
                           periods=3, tz=tz, freq='H')
        expected = DatetimeIndex(['2010-11-01 05:00', '2010-11-01 06:00',
                                  '2010-11-01 07:00'], freq='H', tz=tz)

        # FIXME: these raise ValueError with transpose=True
        dates = tm.box_expected(dates, box_with_array, transpose=False)
        expected = tm.box_expected(expected, box_with_array, transpose=False)

        # TODO: parametrize over the scalar being added?  radd?  sub?
        offset = dates + pd.offsets.Hour(5)
        tm.assert_equal(offset, expected)
        offset = dates + np.timedelta64(5, 'h')
        tm.assert_equal(offset, expected)
        offset = dates + timedelta(hours=5)
        tm.assert_equal(offset, expected)

    # -------------------------------------------------------------
    # RelativeDelta DateOffsets

    def test_dt64arr_add_sub_relativedelta_offsets(self, box_with_array):
        # GH#10699
        vec = DatetimeIndex([Timestamp('2000-01-05 00:15:00'),
                             Timestamp('2000-01-31 00:23:00'),
                             Timestamp('2000-01-01'),
                             Timestamp('2000-03-31'),
                             Timestamp('2000-02-29'),
                             Timestamp('2000-12-31'),
                             Timestamp('2000-05-15'),
                             Timestamp('2001-06-15')])
        vec = tm.box_expected(vec, box_with_array)
        vec_items = vec.squeeze() if box_with_array is pd.DataFrame else vec

        # DateOffset relativedelta fastpath
        relative_kwargs = [('years', 2), ('months', 5), ('days', 3),
                           ('hours', 5), ('minutes', 10), ('seconds', 2),
                           ('microseconds', 5)]
        for i, kwd in enumerate(relative_kwargs):
            off = pd.DateOffset(**dict([kwd]))

            expected = DatetimeIndex([x + off for x in vec_items])
            expected = tm.box_expected(expected, box_with_array)
            tm.assert_equal(expected, vec + off)

            expected = DatetimeIndex([x - off for x in vec_items])
            expected = tm.box_expected(expected, box_with_array)
            tm.assert_equal(expected, vec - off)

            off = pd.DateOffset(**dict(relative_kwargs[:i + 1]))

            expected = DatetimeIndex([x + off for x in vec_items])
            expected = tm.box_expected(expected, box_with_array)
            tm.assert_equal(expected, vec + off)

            expected = DatetimeIndex([x - off for x in vec_items])
            expected = tm.box_expected(expected, box_with_array)
            tm.assert_equal(expected, vec - off)
            msg = "bad operand type for unary"
            with pytest.raises(TypeError, match=msg):
                off - vec

    # -------------------------------------------------------------
    # Non-Tick, Non-RelativeDelta DateOffsets

    # TODO: redundant with test_dt64arr_add_sub_DateOffset?  that includes
    #  tz-aware cases which this does not
    @pytest.mark.parametrize('cls_and_kwargs', [
        'YearBegin', ('YearBegin', {'month': 5}),
        'YearEnd', ('YearEnd', {'month': 5}),
        'MonthBegin', 'MonthEnd',
        'SemiMonthEnd', 'SemiMonthBegin',
        'Week', ('Week', {'weekday': 3}),
        'Week', ('Week', {'weekday': 6}),
        'BusinessDay', 'BDay', 'QuarterEnd', 'QuarterBegin',
        'CustomBusinessDay', 'CDay', 'CBMonthEnd',
        'CBMonthBegin', 'BMonthBegin', 'BMonthEnd',
        'BusinessHour', 'BYearBegin', 'BYearEnd',
        'BQuarterBegin', ('LastWeekOfMonth', {'weekday': 2}),
        ('FY5253Quarter', {'qtr_with_extra_week': 1,
                           'startingMonth': 1,
                           'weekday': 2,
                           'variation': 'nearest'}),
        ('FY5253', {'weekday': 0, 'startingMonth': 2, 'variation': 'nearest'}),
        ('WeekOfMonth', {'weekday': 2, 'week': 2}),
        'Easter', ('DateOffset', {'day': 4}),
        ('DateOffset', {'month': 5})])
    @pytest.mark.parametrize('normalize', [True, False])
    @pytest.mark.parametrize('n', [0, 5])
    def test_dt64arr_add_sub_DateOffsets(self, box_with_array,
                                         n, normalize, cls_and_kwargs):
        # GH#10699
        # assert vectorized operation matches pointwise operations

        if isinstance(cls_and_kwargs, tuple):
            # If cls_name param is a tuple, then 2nd entry is kwargs for
            # the offset constructor
            cls_name, kwargs = cls_and_kwargs
        else:
            cls_name = cls_and_kwargs
            kwargs = {}

        if n == 0 and cls_name in ['WeekOfMonth', 'LastWeekOfMonth',
                                   'FY5253Quarter', 'FY5253']:
            # passing n = 0 is invalid for these offset classes
            return

        vec = DatetimeIndex([Timestamp('2000-01-05 00:15:00'),
                             Timestamp('2000-01-31 00:23:00'),
                             Timestamp('2000-01-01'),
                             Timestamp('2000-03-31'),
                             Timestamp('2000-02-29'),
                             Timestamp('2000-12-31'),
                             Timestamp('2000-05-15'),
                             Timestamp('2001-06-15')])
        vec = tm.box_expected(vec, box_with_array)
        vec_items = vec.squeeze() if box_with_array is pd.DataFrame else vec

        offset_cls = getattr(pd.offsets, cls_name)

        with warnings.catch_warnings(record=True):
            # pandas.errors.PerformanceWarning: Non-vectorized DateOffset being
            # applied to Series or DatetimeIndex
            # we aren't testing that here, so ignore.
            warnings.simplefilter("ignore", PerformanceWarning)

            offset = offset_cls(n, normalize=normalize, **kwargs)

            expected = DatetimeIndex([x + offset for x in vec_items])
            expected = tm.box_expected(expected, box_with_array)
            tm.assert_equal(expected, vec + offset)

            expected = DatetimeIndex([x - offset for x in vec_items])
            expected = tm.box_expected(expected, box_with_array)
            tm.assert_equal(expected, vec - offset)

            expected = DatetimeIndex([offset + x for x in vec_items])
            expected = tm.box_expected(expected, box_with_array)
            tm.assert_equal(expected, offset + vec)
            msg = "bad operand type for unary"
            with pytest.raises(TypeError, match=msg):
                offset - vec

    def test_dt64arr_add_sub_DateOffset(self, box_with_array):
        # GH#10699
        s = date_range('2000-01-01', '2000-01-31', name='a')
        s = tm.box_expected(s, box_with_array)
        result = s + pd.DateOffset(years=1)
        result2 = pd.DateOffset(years=1) + s
        exp = date_range('2001-01-01', '2001-01-31', name='a')
        exp = tm.box_expected(exp, box_with_array)
        tm.assert_equal(result, exp)
        tm.assert_equal(result2, exp)

        result = s - pd.DateOffset(years=1)
        exp = date_range('1999-01-01', '1999-01-31', name='a')
        exp = tm.box_expected(exp, box_with_array)
        tm.assert_equal(result, exp)

        s = DatetimeIndex([Timestamp('2000-01-15 00:15:00', tz='US/Central'),
                           Timestamp('2000-02-15', tz='US/Central')], name='a')
        # FIXME: ValueError with tzaware DataFrame transpose
        s = tm.box_expected(s, box_with_array, transpose=False)
        result = s + pd.offsets.Day()
        result2 = pd.offsets.Day() + s
        exp = DatetimeIndex([Timestamp('2000-01-16 00:15:00', tz='US/Central'),
                             Timestamp('2000-02-16', tz='US/Central')],
                            name='a')
        exp = tm.box_expected(exp, box_with_array, transpose=False)
        tm.assert_equal(result, exp)
        tm.assert_equal(result2, exp)

        s = DatetimeIndex([Timestamp('2000-01-15 00:15:00', tz='US/Central'),
                           Timestamp('2000-02-15', tz='US/Central')], name='a')
        s = tm.box_expected(s, box_with_array, transpose=False)
        result = s + pd.offsets.MonthEnd()
        result2 = pd.offsets.MonthEnd() + s
        exp = DatetimeIndex([Timestamp('2000-01-31 00:15:00', tz='US/Central'),
                             Timestamp('2000-02-29', tz='US/Central')],
                            name='a')
        exp = tm.box_expected(exp, box_with_array, transpose=False)
        tm.assert_equal(result, exp)
        tm.assert_equal(result2, exp)

    # TODO: __sub__, __rsub__
    def test_dt64arr_add_mixed_offset_array(self, box_with_array):
        # GH#10699
        # array of offsets
        s = DatetimeIndex([Timestamp('2000-1-1'), Timestamp('2000-2-1')])
        s = tm.box_expected(s, box_with_array)

        warn = None if box_with_array is pd.DataFrame else PerformanceWarning
        with tm.assert_produces_warning(warn,
                                        clear=[pd.core.arrays.datetimelike]):
            other = pd.Index([pd.offsets.DateOffset(years=1),
                              pd.offsets.MonthEnd()])
            other = tm.box_expected(other, box_with_array)
            result = s + other
            exp = DatetimeIndex([Timestamp('2001-1-1'),
                                 Timestamp('2000-2-29')])
            exp = tm.box_expected(exp, box_with_array)
            tm.assert_equal(result, exp)

            # same offset
            other = pd.Index([pd.offsets.DateOffset(years=1),
                              pd.offsets.DateOffset(years=1)])
            other = tm.box_expected(other, box_with_array)
            result = s + other
            exp = DatetimeIndex([Timestamp('2001-1-1'),
                                 Timestamp('2001-2-1')])
            exp = tm.box_expected(exp, box_with_array)
            tm.assert_equal(result, exp)

    # TODO: overlap with test_dt64arr_add_mixed_offset_array?
    def test_dt64arr_add_sub_offset_ndarray(self, tz_naive_fixture,
                                            box_with_array):
        # GH#18849
        if box_with_array is pd.DataFrame:
            pytest.xfail("FIXME: ValueError with transpose; "
                         "alignment error without")

        tz = tz_naive_fixture
        dti = pd.date_range('2017-01-01', periods=2, tz=tz)
        dtarr = tm.box_expected(dti, box_with_array)

        other = np.array([pd.offsets.MonthEnd(), pd.offsets.Day(n=2)])

        warn = None if box_with_array is pd.DataFrame else PerformanceWarning
        with tm.assert_produces_warning(warn,
                                        clear=[pd.core.arrays.datetimelike]):
            res = dtarr + other
        expected = DatetimeIndex([dti[n] + other[n] for n in range(len(dti))],
                                 name=dti.name, freq='infer')
        expected = tm.box_expected(expected, box_with_array)
        tm.assert_equal(res, expected)

        with tm.assert_produces_warning(warn,
                                        clear=[pd.core.arrays.datetimelike]):
            res2 = other + dtarr
        tm.assert_equal(res2, expected)

        with tm.assert_produces_warning(warn,
                                        clear=[pd.core.arrays.datetimelike]):
            res = dtarr - other
        expected = DatetimeIndex([dti[n] - other[n] for n in range(len(dti))],
                                 name=dti.name, freq='infer')
        expected = tm.box_expected(expected, box_with_array)
        tm.assert_equal(res, expected)


class TestDatetime64OverflowHandling(object):
    # TODO: box + de-duplicate

    def test_dt64_overflow_masking(self, box_with_array):
        # GH#25317
        left = Series([Timestamp('1969-12-31')])
        right = Series([NaT])

        left = tm.box_expected(left, box_with_array)
        right = tm.box_expected(right, box_with_array)

        expected = TimedeltaIndex([NaT])
        expected = tm.box_expected(expected, box_with_array)

        result = left - right
        tm.assert_equal(result, expected)

    def test_dt64_series_arith_overflow(self):
        # GH#12534, fixed by GH#19024
        dt = pd.Timestamp('1700-01-31')
        td = pd.Timedelta('20000 Days')
        dti = pd.date_range('1949-09-30', freq='100Y', periods=4)
        ser = pd.Series(dti)
        msg = 'Overflow in int64 addition'
        with pytest.raises(OverflowError, match=msg):
            ser - dt
        with pytest.raises(OverflowError, match=msg):
            dt - ser
        with pytest.raises(OverflowError, match=msg):
            ser + td
        with pytest.raises(OverflowError, match=msg):
            td + ser

        ser.iloc[-1] = pd.NaT
        expected = pd.Series(['2004-10-03', '2104-10-04', '2204-10-04', 'NaT'],
                             dtype='datetime64[ns]')
        res = ser + td
        tm.assert_series_equal(res, expected)
        res = td + ser
        tm.assert_series_equal(res, expected)

        ser.iloc[1:] = pd.NaT
        expected = pd.Series(['91279 Days', 'NaT', 'NaT', 'NaT'],
                             dtype='timedelta64[ns]')
        res = ser - dt
        tm.assert_series_equal(res, expected)
        res = dt - ser
        tm.assert_series_equal(res, -expected)

    def test_datetimeindex_sub_timestamp_overflow(self):
        dtimax = pd.to_datetime(['now', pd.Timestamp.max])
        dtimin = pd.to_datetime(['now', pd.Timestamp.min])

        tsneg = Timestamp('1950-01-01')
        ts_neg_variants = [tsneg,
                           tsneg.to_pydatetime(),
                           tsneg.to_datetime64().astype('datetime64[ns]'),
                           tsneg.to_datetime64().astype('datetime64[D]')]

        tspos = Timestamp('1980-01-01')
        ts_pos_variants = [tspos,
                           tspos.to_pydatetime(),
                           tspos.to_datetime64().astype('datetime64[ns]'),
                           tspos.to_datetime64().astype('datetime64[D]')]
        msg = 'Overflow in int64 addition'
        for variant in ts_neg_variants:
            with pytest.raises(OverflowError, match=msg):
                dtimax - variant

        expected = pd.Timestamp.max.value - tspos.value
        for variant in ts_pos_variants:
            res = dtimax - variant
            assert res[1].value == expected

        expected = pd.Timestamp.min.value - tsneg.value
        for variant in ts_neg_variants:
            res = dtimin - variant
            assert res[1].value == expected

        for variant in ts_pos_variants:
            with pytest.raises(OverflowError, match=msg):
                dtimin - variant

    def test_datetimeindex_sub_datetimeindex_overflow(self):
        # GH#22492, GH#22508
        dtimax = pd.to_datetime(['now', pd.Timestamp.max])
        dtimin = pd.to_datetime(['now', pd.Timestamp.min])

        ts_neg = pd.to_datetime(['1950-01-01', '1950-01-01'])
        ts_pos = pd.to_datetime(['1980-01-01', '1980-01-01'])

        # General tests
        expected = pd.Timestamp.max.value - ts_pos[1].value
        result = dtimax - ts_pos
        assert result[1].value == expected

        expected = pd.Timestamp.min.value - ts_neg[1].value
        result = dtimin - ts_neg
        assert result[1].value == expected
        msg = 'Overflow in int64 addition'
        with pytest.raises(OverflowError, match=msg):
            dtimax - ts_neg

        with pytest.raises(OverflowError, match=msg):
            dtimin - ts_pos

        # Edge cases
        tmin = pd.to_datetime([pd.Timestamp.min])
        t1 = tmin + pd.Timedelta.max + pd.Timedelta('1us')
        with pytest.raises(OverflowError, match=msg):
            t1 - tmin

        tmax = pd.to_datetime([pd.Timestamp.max])
        t2 = tmax + pd.Timedelta.min - pd.Timedelta('1us')
        with pytest.raises(OverflowError, match=msg):
            tmax - t2


class TestTimestampSeriesArithmetic(object):

    def test_empty_series_add_sub(self):
        # GH#13844
        a = Series(dtype='M8[ns]')
        b = Series(dtype='m8[ns]')
        tm.assert_series_equal(a, a + b)
        tm.assert_series_equal(a, a - b)
        tm.assert_series_equal(a, b + a)
        msg = 'cannot subtract'
        with pytest.raises(TypeError, match=msg):
            b - a

    def test_operators_datetimelike(self):

        # ## timedelta64 ###
        td1 = Series([timedelta(minutes=5, seconds=3)] * 3)
        td1.iloc[2] = np.nan

        # ## datetime64 ###
        dt1 = Series([pd.Timestamp('20111230'), pd.Timestamp('20120101'),
                      pd.Timestamp('20120103')])
        dt1.iloc[2] = np.nan
        dt2 = Series([pd.Timestamp('20111231'), pd.Timestamp('20120102'),
                      pd.Timestamp('20120104')])
        dt1 - dt2
        dt2 - dt1

        # ## datetime64 with timetimedelta ###
        dt1 + td1
        td1 + dt1
        dt1 - td1
        # TODO: Decide if this ought to work.
        # td1 - dt1

        # ## timetimedelta with datetime64 ###
        td1 + dt1
        dt1 + td1

    def test_dt64ser_sub_datetime_dtype(self):
        ts = Timestamp(datetime(1993, 1, 7, 13, 30, 00))
        dt = datetime(1993, 6, 22, 13, 30)
        ser = Series([ts])
        result = pd.to_timedelta(np.abs(ser - dt))
        assert result.dtype == 'timedelta64[ns]'

    # -------------------------------------------------------------
    # TODO: This next block of tests came from tests.series.test_operators,
    # needs to be de-duplicated and parametrized over `box` classes

    def test_operators_datetimelike_invalid(self, all_arithmetic_operators):
        # these are all TypeEror ops
        op_str = all_arithmetic_operators

        def check(get_ser, test_ser):

            # check that we are getting a TypeError
            # with 'operate' (from core/ops.py) for the ops that are not
            # defined
            op = getattr(get_ser, op_str, None)
            # Previously, _validate_for_numeric_binop in core/indexes/base.py
            # did this for us.
            with pytest.raises(TypeError,
                               match='operate|[cC]annot|unsupported operand'):
                op(test_ser)

        # ## timedelta64 ###
        td1 = Series([timedelta(minutes=5, seconds=3)] * 3)
        td1.iloc[2] = np.nan

        # ## datetime64 ###
        dt1 = Series([Timestamp('20111230'), Timestamp('20120101'),
                      Timestamp('20120103')])
        dt1.iloc[2] = np.nan
        dt2 = Series([Timestamp('20111231'), Timestamp('20120102'),
                      Timestamp('20120104')])
        if op_str not in ['__sub__', '__rsub__']:
            check(dt1, dt2)

        # ## datetime64 with timetimedelta ###
        # TODO(jreback) __rsub__ should raise?
        if op_str not in ['__add__', '__radd__', '__sub__']:
            check(dt1, td1)

        # 8260, 10763
        # datetime64 with tz
        tz = 'US/Eastern'
        dt1 = Series(date_range('2000-01-01 09:00:00', periods=5,
                                tz=tz), name='foo')
        dt2 = dt1.copy()
        dt2.iloc[2] = np.nan
        td1 = Series(pd.timedelta_range('1 days 1 min', periods=5, freq='H'))
        td2 = td1.copy()
        td2.iloc[1] = np.nan

        if op_str not in ['__add__', '__radd__', '__sub__', '__rsub__']:
            check(dt2, td2)

    def test_sub_single_tz(self):
        # GH#12290
        s1 = Series([pd.Timestamp('2016-02-10', tz='America/Sao_Paulo')])
        s2 = Series([pd.Timestamp('2016-02-08', tz='America/Sao_Paulo')])
        result = s1 - s2
        expected = Series([Timedelta('2days')])
        tm.assert_series_equal(result, expected)
        result = s2 - s1
        expected = Series([Timedelta('-2days')])
        tm.assert_series_equal(result, expected)

    def test_dt64tz_series_sub_dtitz(self):
        # GH#19071 subtracting tzaware DatetimeIndex from tzaware Series
        # (with same tz) raises, fixed by #19024
        dti = pd.date_range('1999-09-30', periods=10, tz='US/Pacific')
        ser = pd.Series(dti)
        expected = pd.Series(pd.TimedeltaIndex(['0days'] * 10))

        res = dti - ser
        tm.assert_series_equal(res, expected)
        res = ser - dti
        tm.assert_series_equal(res, expected)

    def test_sub_datetime_compat(self):
        # see GH#14088
        s = Series([datetime(2016, 8, 23, 12, tzinfo=pytz.utc), pd.NaT])
        dt = datetime(2016, 8, 22, 12, tzinfo=pytz.utc)
        exp = Series([Timedelta('1 days'), pd.NaT])
        tm.assert_series_equal(s - dt, exp)
        tm.assert_series_equal(s - Timestamp(dt), exp)

    def test_dt64_series_add_mixed_tick_DateOffset(self):
        # GH#4532
        # operate with pd.offsets
        s = Series([Timestamp('20130101 9:01'), Timestamp('20130101 9:02')])

        result = s + pd.offsets.Milli(5)
        result2 = pd.offsets.Milli(5) + s
        expected = Series([Timestamp('20130101 9:01:00.005'),
                           Timestamp('20130101 9:02:00.005')])
        tm.assert_series_equal(result, expected)
        tm.assert_series_equal(result2, expected)

        result = s + pd.offsets.Minute(5) + pd.offsets.Milli(5)
        expected = Series([Timestamp('20130101 9:06:00.005'),
                           Timestamp('20130101 9:07:00.005')])
        tm.assert_series_equal(result, expected)

    def test_datetime64_ops_nat(self):
        # GH#11349
        datetime_series = Series([NaT, Timestamp('19900315')])
        nat_series_dtype_timestamp = Series([NaT, NaT], dtype='datetime64[ns]')
        single_nat_dtype_datetime = Series([NaT], dtype='datetime64[ns]')

        # subtraction
        tm.assert_series_equal(-NaT + datetime_series,
                               nat_series_dtype_timestamp)
        msg = 'Unary negative expects'
        with pytest.raises(TypeError, match=msg):
            -single_nat_dtype_datetime + datetime_series

        tm.assert_series_equal(-NaT + nat_series_dtype_timestamp,
                               nat_series_dtype_timestamp)
        with pytest.raises(TypeError, match=msg):
            -single_nat_dtype_datetime + nat_series_dtype_timestamp

        # addition
        tm.assert_series_equal(nat_series_dtype_timestamp + NaT,
                               nat_series_dtype_timestamp)
        tm.assert_series_equal(NaT + nat_series_dtype_timestamp,
                               nat_series_dtype_timestamp)

        tm.assert_series_equal(nat_series_dtype_timestamp + NaT,
                               nat_series_dtype_timestamp)
        tm.assert_series_equal(NaT + nat_series_dtype_timestamp,
                               nat_series_dtype_timestamp)

    # -------------------------------------------------------------
    # Invalid Operations
    # TODO: this block also needs to be de-duplicated and parametrized

    @pytest.mark.parametrize('dt64_series', [
        Series([Timestamp('19900315'), Timestamp('19900315')]),
        Series([pd.NaT, Timestamp('19900315')]),
        Series([pd.NaT, pd.NaT], dtype='datetime64[ns]')])
    @pytest.mark.parametrize('one', [1, 1.0, np.array(1)])
    def test_dt64_mul_div_numeric_invalid(self, one, dt64_series):
        # multiplication
        msg = 'cannot perform .* with this index type'
        with pytest.raises(TypeError, match=msg):
            dt64_series * one
        with pytest.raises(TypeError, match=msg):
            one * dt64_series

        # division
        with pytest.raises(TypeError, match=msg):
            dt64_series / one
        with pytest.raises(TypeError, match=msg):
            one / dt64_series

    @pytest.mark.parametrize('op', ['__add__', '__radd__',
                                    '__sub__', '__rsub__'])
    @pytest.mark.parametrize('tz', [None, 'Asia/Tokyo'])
    def test_dt64_series_add_intlike(self, tz, op):
        # GH#19123
        dti = pd.DatetimeIndex(['2016-01-02', '2016-02-03', 'NaT'], tz=tz)
        ser = Series(dti)

        other = Series([20, 30, 40], dtype='uint8')

        method = getattr(ser, op)
        msg = '|'.join(['incompatible type for a .* operation',
                        'cannot evaluate a numeric op',
                        'ufunc .* cannot use operands',
                        'cannot (add|subtract)'])
        with pytest.raises(TypeError, match=msg):
            method(1)
        with pytest.raises(TypeError, match=msg):
            method(other)
        with pytest.raises(TypeError, match=msg):
            method(other.values)
        with pytest.raises(TypeError, match=msg):
            method(pd.Index(other))

    # -------------------------------------------------------------
    # Timezone-Centric Tests

    def test_operators_datetimelike_with_timezones(self):
        tz = 'US/Eastern'
        dt1 = Series(date_range('2000-01-01 09:00:00', periods=5,
                                tz=tz), name='foo')
        dt2 = dt1.copy()
        dt2.iloc[2] = np.nan

        td1 = Series(pd.timedelta_range('1 days 1 min', periods=5, freq='H'))
        td2 = td1.copy()
        td2.iloc[1] = np.nan

        result = dt1 + td1[0]
        exp = (dt1.dt.tz_localize(None) + td1[0]).dt.tz_localize(tz)
        tm.assert_series_equal(result, exp)

        result = dt2 + td2[0]
        exp = (dt2.dt.tz_localize(None) + td2[0]).dt.tz_localize(tz)
        tm.assert_series_equal(result, exp)

        # odd numpy behavior with scalar timedeltas
        result = td1[0] + dt1
        exp = (dt1.dt.tz_localize(None) + td1[0]).dt.tz_localize(tz)
        tm.assert_series_equal(result, exp)

        result = td2[0] + dt2
        exp = (dt2.dt.tz_localize(None) + td2[0]).dt.tz_localize(tz)
        tm.assert_series_equal(result, exp)

        result = dt1 - td1[0]
        exp = (dt1.dt.tz_localize(None) - td1[0]).dt.tz_localize(tz)
        tm.assert_series_equal(result, exp)
        msg = "bad operand type for unary"
        with pytest.raises(TypeError, match=msg):
            td1[0] - dt1

        result = dt2 - td2[0]
        exp = (dt2.dt.tz_localize(None) - td2[0]).dt.tz_localize(tz)
        tm.assert_series_equal(result, exp)
        with pytest.raises(TypeError, match=msg):
            td2[0] - dt2

        result = dt1 + td1
        exp = (dt1.dt.tz_localize(None) + td1).dt.tz_localize(tz)
        tm.assert_series_equal(result, exp)

        result = dt2 + td2
        exp = (dt2.dt.tz_localize(None) + td2).dt.tz_localize(tz)
        tm.assert_series_equal(result, exp)

        result = dt1 - td1
        exp = (dt1.dt.tz_localize(None) - td1).dt.tz_localize(tz)
        tm.assert_series_equal(result, exp)

        result = dt2 - td2
        exp = (dt2.dt.tz_localize(None) - td2).dt.tz_localize(tz)
        tm.assert_series_equal(result, exp)
        msg = 'cannot (add|subtract)'
        with pytest.raises(TypeError, match=msg):
            td1 - dt1
        with pytest.raises(TypeError, match=msg):
            td2 - dt2


class TestDatetimeIndexArithmetic(object):

    # -------------------------------------------------------------
    # Binary operations DatetimeIndex and int

    def test_dti_add_int(self, tz_naive_fixture, one):
        # Variants of `one` for #19012
        tz = tz_naive_fixture
        rng = pd.date_range('2000-01-01 09:00', freq='H',
                            periods=10, tz=tz)
        with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
            result = rng + one
        expected = pd.date_range('2000-01-01 10:00', freq='H',
                                 periods=10, tz=tz)
        tm.assert_index_equal(result, expected)

    def test_dti_iadd_int(self, tz_naive_fixture, one):
        tz = tz_naive_fixture
        rng = pd.date_range('2000-01-01 09:00', freq='H',
                            periods=10, tz=tz)
        expected = pd.date_range('2000-01-01 10:00', freq='H',
                                 periods=10, tz=tz)
        with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
            rng += one
        tm.assert_index_equal(rng, expected)

    def test_dti_sub_int(self, tz_naive_fixture, one):
        tz = tz_naive_fixture
        rng = pd.date_range('2000-01-01 09:00', freq='H',
                            periods=10, tz=tz)
        with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
            result = rng - one
        expected = pd.date_range('2000-01-01 08:00', freq='H',
                                 periods=10, tz=tz)
        tm.assert_index_equal(result, expected)

    def test_dti_isub_int(self, tz_naive_fixture, one):
        tz = tz_naive_fixture
        rng = pd.date_range('2000-01-01 09:00', freq='H',
                            periods=10, tz=tz)
        expected = pd.date_range('2000-01-01 08:00', freq='H',
                                 periods=10, tz=tz)
        with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
            rng -= one
        tm.assert_index_equal(rng, expected)

    # -------------------------------------------------------------
    # __add__/__sub__ with integer arrays

    @pytest.mark.parametrize('freq', ['H', 'D'])
    @pytest.mark.parametrize('int_holder', [np.array, pd.Index])
    def test_dti_add_intarray_tick(self, int_holder, freq):
        # GH#19959
        dti = pd.date_range('2016-01-01', periods=2, freq=freq)
        other = int_holder([4, -1])

        with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
            expected = DatetimeIndex([dti[n] + other[n]
                                      for n in range(len(dti))])
            result = dti + other
        tm.assert_index_equal(result, expected)

        with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
            result = other + dti
        tm.assert_index_equal(result, expected)

    @pytest.mark.parametrize('freq', ['W', 'M', 'MS', 'Q'])
    @pytest.mark.parametrize('int_holder', [np.array, pd.Index])
    def test_dti_add_intarray_non_tick(self, int_holder, freq):
        # GH#19959
        dti = pd.date_range('2016-01-01', periods=2, freq=freq)
        other = int_holder([4, -1])

        with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
            expected = DatetimeIndex([dti[n] + other[n]
                                      for n in range(len(dti))])

        # tm.assert_produces_warning does not handle cases where we expect
        # two warnings, in this case PerformanceWarning and FutureWarning.
        # Until that is fixed, we don't catch either
        with warnings.catch_warnings():
            warnings.simplefilter("ignore")
            result = dti + other
        tm.assert_index_equal(result, expected)

        with warnings.catch_warnings():
            warnings.simplefilter("ignore")
            result = other + dti
        tm.assert_index_equal(result, expected)

    @pytest.mark.parametrize('int_holder', [np.array, pd.Index])
    def test_dti_add_intarray_no_freq(self, int_holder):
        # GH#19959
        dti = pd.DatetimeIndex(['2016-01-01', 'NaT', '2017-04-05 06:07:08'])
        other = int_holder([9, 4, -1])
        nfmsg = 'Cannot shift with no freq'
        tmsg = 'cannot subtract DatetimeArray from'
        with pytest.raises(NullFrequencyError, match=nfmsg):
            dti + other
        with pytest.raises(NullFrequencyError, match=nfmsg):
            other + dti
        with pytest.raises(NullFrequencyError, match=nfmsg):
            dti - other
        with pytest.raises(TypeError, match=tmsg):
            other - dti

    # -------------------------------------------------------------
    # Binary operations DatetimeIndex and TimedeltaIndex/array

    def test_dti_add_tdi(self, tz_naive_fixture):
        # GH#17558
        tz = tz_naive_fixture
        dti = DatetimeIndex([Timestamp('2017-01-01', tz=tz)] * 10)
        tdi = pd.timedelta_range('0 days', periods=10)
        expected = pd.date_range('2017-01-01', periods=10, tz=tz)

        # add with TimdeltaIndex
        result = dti + tdi
        tm.assert_index_equal(result, expected)

        result = tdi + dti
        tm.assert_index_equal(result, expected)

        # add with timedelta64 array
        result = dti + tdi.values
        tm.assert_index_equal(result, expected)

        result = tdi.values + dti
        tm.assert_index_equal(result, expected)

    def test_dti_iadd_tdi(self, tz_naive_fixture):
        # GH#17558
        tz = tz_naive_fixture
        dti = DatetimeIndex([Timestamp('2017-01-01', tz=tz)] * 10)
        tdi = pd.timedelta_range('0 days', periods=10)
        expected = pd.date_range('2017-01-01', periods=10, tz=tz)

        # iadd with TimdeltaIndex
        result = DatetimeIndex([Timestamp('2017-01-01', tz=tz)] * 10)
        result += tdi
        tm.assert_index_equal(result, expected)

        result = pd.timedelta_range('0 days', periods=10)
        result += dti
        tm.assert_index_equal(result, expected)

        # iadd with timedelta64 array
        result = DatetimeIndex([Timestamp('2017-01-01', tz=tz)] * 10)
        result += tdi.values
        tm.assert_index_equal(result, expected)

        result = pd.timedelta_range('0 days', periods=10)
        result += dti
        tm.assert_index_equal(result, expected)

    def test_dti_sub_tdi(self, tz_naive_fixture):
        # GH#17558
        tz = tz_naive_fixture
        dti = DatetimeIndex([Timestamp('2017-01-01', tz=tz)] * 10)
        tdi = pd.timedelta_range('0 days', periods=10)
        expected = pd.date_range('2017-01-01', periods=10, tz=tz, freq='-1D')

        # sub with TimedeltaIndex
        result = dti - tdi
        tm.assert_index_equal(result, expected)

        msg = 'cannot subtract .*TimedeltaArray'
        with pytest.raises(TypeError, match=msg):
            tdi - dti

        # sub with timedelta64 array
        result = dti - tdi.values
        tm.assert_index_equal(result, expected)

        msg = 'cannot subtract DatetimeArray from'
        with pytest.raises(TypeError, match=msg):
            tdi.values - dti

    def test_dti_isub_tdi(self, tz_naive_fixture):
        # GH#17558
        tz = tz_naive_fixture
        dti = DatetimeIndex([Timestamp('2017-01-01', tz=tz)] * 10)
        tdi = pd.timedelta_range('0 days', periods=10)
        expected = pd.date_range('2017-01-01', periods=10, tz=tz, freq='-1D')

        # isub with TimedeltaIndex
        result = DatetimeIndex([Timestamp('2017-01-01', tz=tz)] * 10)
        result -= tdi
        tm.assert_index_equal(result, expected)

        msg = 'cannot subtract .* from a TimedeltaArray'
        with pytest.raises(TypeError, match=msg):
            tdi -= dti

        # isub with timedelta64 array
        result = DatetimeIndex([Timestamp('2017-01-01', tz=tz)] * 10)
        result -= tdi.values
        tm.assert_index_equal(result, expected)

        msg = '|'.join(['cannot perform __neg__ with this index type:',
                        'ufunc subtract cannot use operands with types',
                        'cannot subtract DatetimeArray from'])
        with pytest.raises(TypeError, match=msg):
            tdi.values -= dti

    # -------------------------------------------------------------
    # Binary Operations DatetimeIndex and datetime-like
    # TODO: A couple other tests belong in this section.  Move them in
    # A PR where there isn't already a giant diff.

    @pytest.mark.parametrize('addend', [
        datetime(2011, 1, 1),
        DatetimeIndex(['2011-01-01', '2011-01-02']),
        DatetimeIndex(['2011-01-01', '2011-01-02']).tz_localize('US/Eastern'),
        np.datetime64('2011-01-01'),
        Timestamp('2011-01-01')
    ], ids=lambda x: type(x).__name__)
    @pytest.mark.parametrize('tz', [None, 'US/Eastern'])
    def test_add_datetimelike_and_dti(self, addend, tz):
        # GH#9631
        dti = DatetimeIndex(['2011-01-01', '2011-01-02']).tz_localize(tz)
        msg = ('cannot add DatetimeArray and {0}'
               .format(type(addend).__name__)).replace('DatetimeIndex',
                                                       'DatetimeArray')
        with pytest.raises(TypeError, match=msg):
            dti + addend
        with pytest.raises(TypeError, match=msg):
            addend + dti

    # -------------------------------------------------------------

    def test_sub_dti_dti(self):
        # previously performed setop (deprecated in 0.16.0), now changed to
        # return subtraction -> TimeDeltaIndex (GH ...)

        dti = date_range('20130101', periods=3)
        dti_tz = date_range('20130101', periods=3).tz_localize('US/Eastern')
        dti_tz2 = date_range('20130101', periods=3).tz_localize('UTC')
        expected = TimedeltaIndex([0, 0, 0])

        result = dti - dti
        tm.assert_index_equal(result, expected)

        result = dti_tz - dti_tz
        tm.assert_index_equal(result, expected)
        msg = 'DatetimeArray subtraction must have the same timezones or'
        with pytest.raises(TypeError, match=msg):
            dti_tz - dti

        with pytest.raises(TypeError, match=msg):
            dti - dti_tz

        with pytest.raises(TypeError, match=msg):
            dti_tz - dti_tz2

        # isub
        dti -= dti
        tm.assert_index_equal(dti, expected)

        # different length raises ValueError
        dti1 = date_range('20130101', periods=3)
        dti2 = date_range('20130101', periods=4)
        msg = 'cannot add indices of unequal length'
        with pytest.raises(ValueError, match=msg):
            dti1 - dti2

        # NaN propagation
        dti1 = DatetimeIndex(['2012-01-01', np.nan, '2012-01-03'])
        dti2 = DatetimeIndex(['2012-01-02', '2012-01-03', np.nan])
        expected = TimedeltaIndex(['1 days', np.nan, np.nan])
        result = dti2 - dti1
        tm.assert_index_equal(result, expected)

    # -------------------------------------------------------------------
    # TODO: Most of this block is moved from series or frame tests, needs
    # cleanup, box-parametrization, and de-duplication

    @pytest.mark.parametrize('op', [operator.add, operator.sub])
    def test_timedelta64_equal_timedelta_supported_ops(self, op):
        ser = Series([Timestamp('20130301'),
                      Timestamp('20130228 23:00:00'),
                      Timestamp('20130228 22:00:00'),
                      Timestamp('20130228 21:00:00')])

        intervals = ['D', 'h', 'm', 's', 'us']

        # TODO: unused
        # npy16_mappings = {'D': 24 * 60 * 60 * 1000000,
        #                   'h': 60 * 60 * 1000000,
        #                   'm': 60 * 1000000,
        #                   's': 1000000,
        #                   'us': 1}

        def timedelta64(*args):
            return sum(starmap(np.timedelta64, zip(args, intervals)))

        for d, h, m, s, us in product(*([range(2)] * 5)):
            nptd = timedelta64(d, h, m, s, us)
            pytd = timedelta(days=d, hours=h, minutes=m, seconds=s,
                             microseconds=us)
            lhs = op(ser, nptd)
            rhs = op(ser, pytd)

            tm.assert_series_equal(lhs, rhs)

    def test_ops_nat_mixed_datetime64_timedelta64(self):
        # GH#11349
        timedelta_series = Series([NaT, Timedelta('1s')])
        datetime_series = Series([NaT, Timestamp('19900315')])
        nat_series_dtype_timedelta = Series([NaT, NaT],
                                            dtype='timedelta64[ns]')
        nat_series_dtype_timestamp = Series([NaT, NaT], dtype='datetime64[ns]')
        single_nat_dtype_datetime = Series([NaT], dtype='datetime64[ns]')
        single_nat_dtype_timedelta = Series([NaT], dtype='timedelta64[ns]')

        # subtraction
        tm.assert_series_equal(datetime_series - single_nat_dtype_datetime,
                               nat_series_dtype_timedelta)

        tm.assert_series_equal(datetime_series - single_nat_dtype_timedelta,
                               nat_series_dtype_timestamp)
        tm.assert_series_equal(-single_nat_dtype_timedelta + datetime_series,
                               nat_series_dtype_timestamp)

        # without a Series wrapping the NaT, it is ambiguous
        # whether it is a datetime64 or timedelta64
        # defaults to interpreting it as timedelta64
        tm.assert_series_equal(nat_series_dtype_timestamp -
                               single_nat_dtype_datetime,
                               nat_series_dtype_timedelta)

        tm.assert_series_equal(nat_series_dtype_timestamp -
                               single_nat_dtype_timedelta,
                               nat_series_dtype_timestamp)
        tm.assert_series_equal(-single_nat_dtype_timedelta +
                               nat_series_dtype_timestamp,
                               nat_series_dtype_timestamp)
        msg = 'cannot subtract a datelike'
        with pytest.raises(TypeError, match=msg):
            timedelta_series - single_nat_dtype_datetime

        # addition
        tm.assert_series_equal(nat_series_dtype_timestamp +
                               single_nat_dtype_timedelta,
                               nat_series_dtype_timestamp)
        tm.assert_series_equal(single_nat_dtype_timedelta +
                               nat_series_dtype_timestamp,
                               nat_series_dtype_timestamp)

        tm.assert_series_equal(nat_series_dtype_timestamp +
                               single_nat_dtype_timedelta,
                               nat_series_dtype_timestamp)
        tm.assert_series_equal(single_nat_dtype_timedelta +
                               nat_series_dtype_timestamp,
                               nat_series_dtype_timestamp)

        tm.assert_series_equal(nat_series_dtype_timedelta +
                               single_nat_dtype_datetime,
                               nat_series_dtype_timestamp)
        tm.assert_series_equal(single_nat_dtype_datetime +
                               nat_series_dtype_timedelta,
                               nat_series_dtype_timestamp)

    def test_ufunc_coercions(self):
        idx = date_range('2011-01-01', periods=3, freq='2D', name='x')

        delta = np.timedelta64(1, 'D')
        for result in [idx + delta, np.add(idx, delta)]:
            assert isinstance(result, DatetimeIndex)
            exp = date_range('2011-01-02', periods=3, freq='2D', name='x')
            tm.assert_index_equal(result, exp)
            assert result.freq == '2D'

        for result in [idx - delta, np.subtract(idx, delta)]:
            assert isinstance(result, DatetimeIndex)
            exp = date_range('2010-12-31', periods=3, freq='2D', name='x')
            tm.assert_index_equal(result, exp)
            assert result.freq == '2D'

        delta = np.array([np.timedelta64(1, 'D'), np.timedelta64(2, 'D'),
                          np.timedelta64(3, 'D')])
        for result in [idx + delta, np.add(idx, delta)]:
            assert isinstance(result, DatetimeIndex)
            exp = DatetimeIndex(['2011-01-02', '2011-01-05', '2011-01-08'],
                                freq='3D', name='x')
            tm.assert_index_equal(result, exp)
            assert result.freq == '3D'

        for result in [idx - delta, np.subtract(idx, delta)]:
            assert isinstance(result, DatetimeIndex)
            exp = DatetimeIndex(['2010-12-31', '2011-01-01', '2011-01-02'],
                                freq='D', name='x')
            tm.assert_index_equal(result, exp)
            assert result.freq == 'D'

    @pytest.mark.parametrize('names', [('foo', None, None),
                                       ('baz', 'bar', None),
                                       ('bar', 'bar', 'bar')])
    @pytest.mark.parametrize('tz', [None, 'America/Chicago'])
    def test_dti_add_series(self, tz, names):
        # GH#13905
        index = DatetimeIndex(['2016-06-28 05:30', '2016-06-28 05:31'],
                              tz=tz, name=names[0])
        ser = Series([Timedelta(seconds=5)] * 2,
                     index=index, name=names[1])
        expected = Series(index + Timedelta(seconds=5),
                          index=index, name=names[2])

        # passing name arg isn't enough when names[2] is None
        expected.name = names[2]
        assert expected.dtype == index.dtype
        result = ser + index
        tm.assert_series_equal(result, expected)
        result2 = index + ser
        tm.assert_series_equal(result2, expected)

        expected = index + Timedelta(seconds=5)
        result3 = ser.values + index
        tm.assert_index_equal(result3, expected)
        result4 = index + ser.values
        tm.assert_index_equal(result4, expected)

    @pytest.mark.parametrize('names', [(None, None, None),
                                       ('foo', 'bar', None),
                                       ('foo', 'foo', 'foo')])
    def test_dti_add_offset_index(self, tz_naive_fixture, names):
        # GH#18849, GH#19744
        tz = tz_naive_fixture
        dti = pd.date_range('2017-01-01', periods=2, tz=tz, name=names[0])
        other = pd.Index([pd.offsets.MonthEnd(), pd.offsets.Day(n=2)],
                         name=names[1])

        with tm.assert_produces_warning(PerformanceWarning,
                                        clear=[pd.core.arrays.datetimelike]):
            res = dti + other
        expected = DatetimeIndex([dti[n] + other[n] for n in range(len(dti))],
                                 name=names[2], freq='infer')
        tm.assert_index_equal(res, expected)

        with tm.assert_produces_warning(PerformanceWarning,
                                        clear=[pd.core.arrays.datetimelike]):
            res2 = other + dti
        tm.assert_index_equal(res2, expected)

    @pytest.mark.parametrize('names', [(None, None, None),
                                       ('foo', 'bar', None),
                                       ('foo', 'foo', 'foo')])
    def test_dti_sub_offset_index(self, tz_naive_fixture, names):
        # GH#18824, GH#19744
        tz = tz_naive_fixture
        dti = pd.date_range('2017-01-01', periods=2, tz=tz, name=names[0])
        other = pd.Index([pd.offsets.MonthEnd(), pd.offsets.Day(n=2)],
                         name=names[1])

        with tm.assert_produces_warning(PerformanceWarning,
                                        clear=[pd.core.arrays.datetimelike]):
            res = dti - other
        expected = DatetimeIndex([dti[n] - other[n] for n in range(len(dti))],
                                 name=names[2], freq='infer')
        tm.assert_index_equal(res, expected)

    @pytest.mark.parametrize('names', [(None, None, None),
                                       ('foo', 'bar', None),
                                       ('foo', 'foo', 'foo')])
    def test_dti_with_offset_series(self, tz_naive_fixture, names):
        # GH#18849
        tz = tz_naive_fixture
        dti = pd.date_range('2017-01-01', periods=2, tz=tz, name=names[0])
        other = Series([pd.offsets.MonthEnd(), pd.offsets.Day(n=2)],
                       name=names[1])

        expected_add = Series([dti[n] + other[n] for n in range(len(dti))],
                              name=names[2])

        with tm.assert_produces_warning(PerformanceWarning,
                                        clear=[pd.core.arrays.datetimelike]):
            res = dti + other
        tm.assert_series_equal(res, expected_add)

        with tm.assert_produces_warning(PerformanceWarning,
                                        clear=[pd.core.arrays.datetimelike]):
            res2 = other + dti
        tm.assert_series_equal(res2, expected_add)

        expected_sub = Series([dti[n] - other[n] for n in range(len(dti))],
                              name=names[2])

        with tm.assert_produces_warning(PerformanceWarning,
                                        clear=[pd.core.arrays.datetimelike]):
            res3 = dti - other
        tm.assert_series_equal(res3, expected_sub)


@pytest.mark.parametrize('years', [-1, 0, 1])
@pytest.mark.parametrize('months', [-2, 0, 2])
def test_shift_months(years, months):
    dti = DatetimeIndex([Timestamp('2000-01-05 00:15:00'),
                         Timestamp('2000-01-31 00:23:00'),
                         Timestamp('2000-01-01'),
                         Timestamp('2000-02-29'),
                         Timestamp('2000-12-31')])
    actual = DatetimeIndex(shift_months(dti.asi8, years * 12 + months))

    raw = [x + pd.offsets.DateOffset(years=years, months=months)
           for x in dti]
    expected = DatetimeIndex(raw)
    tm.assert_index_equal(actual, expected)