content: from datetime import datetime
  import warnings
  
  import numpy as np
  import pytest
  
  from pandas.core.dtypes.generic import ABCDateOffset
  
  import pandas as pd
  from pandas import (
      DatetimeIndex,
      Index,
      PeriodIndex,
      Series,
      Timestamp,
      bdate_range,
      date_range,
  )
  from pandas.tests.test_base import Ops
  import pandas.util.testing as tm
  
  from pandas.tseries.offsets import BDay, BMonthEnd, CDay, Day, Hour
  
  START, END = datetime(2009, 1, 1), datetime(2010, 1, 1)
  
  
  class TestDatetimeIndexOps(Ops):
      def setup_method(self, method):
          super().setup_method(method)
          mask = lambda x: (isinstance(x, DatetimeIndex) or isinstance(x, PeriodIndex))
          self.is_valid_objs = [o for o in self.objs if mask(o)]
          self.not_valid_objs = [o for o in self.objs if not mask(o)]
  
      def test_ops_properties(self):
          f = lambda x: isinstance(x, DatetimeIndex)
          self.check_ops_properties(DatetimeIndex._field_ops, f)
          self.check_ops_properties(DatetimeIndex._object_ops, f)
          self.check_ops_properties(DatetimeIndex._bool_ops, f)
  
      def test_ops_properties_basic(self):
  
          # sanity check that the behavior didn't change
          # GH#7206
          msg = "'Series' object has no attribute '{}'"
          for op in ["year", "day", "second", "weekday"]:
              with pytest.raises(AttributeError, match=msg.format(op)):
                  getattr(self.dt_series, op)
  
          # attribute access should still work!
          s = Series(dict(year=2000, month=1, day=10))
          assert s.year == 2000
          assert s.month == 1
          assert s.day == 10
          msg = "'Series' object has no attribute 'weekday'"
          with pytest.raises(AttributeError, match=msg):
              s.weekday
  
      def test_repeat_range(self, tz_naive_fixture):
          tz = tz_naive_fixture
          rng = date_range("1/1/2000", "1/1/2001")
  
          result = rng.repeat(5)
          assert result.freq is None
          assert len(result) == 5 * len(rng)
  
          index = pd.date_range("2001-01-01", periods=2, freq="D", tz=tz)
          exp = pd.DatetimeIndex(
              ["2001-01-01", "2001-01-01", "2001-01-02", "2001-01-02"], tz=tz
          )
          for res in [index.repeat(2), np.repeat(index, 2)]:
              tm.assert_index_equal(res, exp)
              assert res.freq is None
  
          index = pd.date_range("2001-01-01", periods=2, freq="2D", tz=tz)
          exp = pd.DatetimeIndex(
              ["2001-01-01", "2001-01-01", "2001-01-03", "2001-01-03"], tz=tz
          )
          for res in [index.repeat(2), np.repeat(index, 2)]:
              tm.assert_index_equal(res, exp)
              assert res.freq is None
  
          index = pd.DatetimeIndex(["2001-01-01", "NaT", "2003-01-01"], tz=tz)
          exp = pd.DatetimeIndex(
              [
                  "2001-01-01",
                  "2001-01-01",
                  "2001-01-01",
                  "NaT",
                  "NaT",
                  "NaT",
                  "2003-01-01",
                  "2003-01-01",
                  "2003-01-01",
              ],
              tz=tz,
          )
          for res in [index.repeat(3), np.repeat(index, 3)]:
              tm.assert_index_equal(res, exp)
              assert res.freq is None
  
      def test_repeat(self, tz_naive_fixture):
          tz = tz_naive_fixture
          reps = 2
          msg = "the 'axis' parameter is not supported"
  
          rng = pd.date_range(start="2016-01-01", periods=2, freq="30Min", tz=tz)
  
          expected_rng = DatetimeIndex(
              [
                  Timestamp("2016-01-01 00:00:00", tz=tz, freq="30T"),
                  Timestamp("2016-01-01 00:00:00", tz=tz, freq="30T"),
                  Timestamp("2016-01-01 00:30:00", tz=tz, freq="30T"),
                  Timestamp("2016-01-01 00:30:00", tz=tz, freq="30T"),
              ]
          )
  
          res = rng.repeat(reps)
          tm.assert_index_equal(res, expected_rng)
          assert res.freq is None
  
          tm.assert_index_equal(np.repeat(rng, reps), expected_rng)
          with pytest.raises(ValueError, match=msg):
              np.repeat(rng, reps, axis=1)
  
      def test_resolution(self, tz_naive_fixture):
          tz = tz_naive_fixture
          for freq, expected in zip(
              ["A", "Q", "M", "D", "H", "T", "S", "L", "U"],
              [
                  "day",
                  "day",
                  "day",
                  "day",
                  "hour",
                  "minute",
                  "second",
                  "millisecond",
                  "microsecond",
              ],
          ):
              idx = pd.date_range(start="2013-04-01", periods=30, freq=freq, tz=tz)
              assert idx.resolution == expected
  
      def test_value_counts_unique(self, tz_naive_fixture):
          tz = tz_naive_fixture
          # GH 7735
          idx = pd.date_range("2011-01-01 09:00", freq="H", periods=10)
          # create repeated values, 'n'th element is repeated by n+1 times
          idx = DatetimeIndex(np.repeat(idx.values, range(1, len(idx) + 1)), tz=tz)
  
          exp_idx = pd.date_range("2011-01-01 18:00", freq="-1H", periods=10, tz=tz)
          expected = Series(range(10, 0, -1), index=exp_idx, dtype="int64")
  
          for obj in [idx, Series(idx)]:
              tm.assert_series_equal(obj.value_counts(), expected)
  
          expected = pd.date_range("2011-01-01 09:00", freq="H", periods=10, tz=tz)
          tm.assert_index_equal(idx.unique(), expected)
  
          idx = DatetimeIndex(
              [
                  "2013-01-01 09:00",
                  "2013-01-01 09:00",
                  "2013-01-01 09:00",
                  "2013-01-01 08:00",
                  "2013-01-01 08:00",
                  pd.NaT,
              ],
              tz=tz,
          )
  
          exp_idx = DatetimeIndex(["2013-01-01 09:00", "2013-01-01 08:00"], tz=tz)
          expected = Series([3, 2], index=exp_idx)
  
          for obj in [idx, Series(idx)]:
              tm.assert_series_equal(obj.value_counts(), expected)
  
          exp_idx = DatetimeIndex(["2013-01-01 09:00", "2013-01-01 08:00", pd.NaT], tz=tz)
          expected = Series([3, 2, 1], index=exp_idx)
  
          for obj in [idx, Series(idx)]:
              tm.assert_series_equal(obj.value_counts(dropna=False), expected)
  
          tm.assert_index_equal(idx.unique(), exp_idx)
  
      def test_nonunique_contains(self):
          # GH 9512
          for idx in map(
              DatetimeIndex,
              (
                  [0, 1, 0],
                  [0, 0, -1],
                  [0, -1, -1],
                  ["2015", "2015", "2016"],
                  ["2015", "2015", "2014"],
              ),
          ):
              assert idx[0] in idx
  
      @pytest.mark.parametrize(
          "idx",
          [
              DatetimeIndex(
                  ["2011-01-01", "2011-01-02", "2011-01-03"], freq="D", name="idx"
              ),
              DatetimeIndex(
                  ["2011-01-01 09:00", "2011-01-01 10:00", "2011-01-01 11:00"],
                  freq="H",
                  name="tzidx",
                  tz="Asia/Tokyo",
              ),
          ],
      )
      def test_order_with_freq(self, idx):
          ordered = idx.sort_values()
          tm.assert_index_equal(ordered, idx)
          assert ordered.freq == idx.freq
  
          ordered = idx.sort_values(ascending=False)
          expected = idx[::-1]
          tm.assert_index_equal(ordered, expected)
          assert ordered.freq == expected.freq
          assert ordered.freq.n == -1
  
          ordered, indexer = idx.sort_values(return_indexer=True)
          tm.assert_index_equal(ordered, idx)
          tm.assert_numpy_array_equal(indexer, np.array([0, 1, 2]), check_dtype=False)
          assert ordered.freq == idx.freq
  
          ordered, indexer = idx.sort_values(return_indexer=True, ascending=False)
          expected = idx[::-1]
          tm.assert_index_equal(ordered, expected)
          tm.assert_numpy_array_equal(indexer, np.array([2, 1, 0]), check_dtype=False)
          assert ordered.freq == expected.freq
          assert ordered.freq.n == -1
  
      @pytest.mark.parametrize(
          "index_dates,expected_dates",
          [
              (
                  ["2011-01-01", "2011-01-03", "2011-01-05", "2011-01-02", "2011-01-01"],
                  ["2011-01-01", "2011-01-01", "2011-01-02", "2011-01-03", "2011-01-05"],
              ),
              (
                  ["2011-01-01", "2011-01-03", "2011-01-05", "2011-01-02", "2011-01-01"],
                  ["2011-01-01", "2011-01-01", "2011-01-02", "2011-01-03", "2011-01-05"],
              ),
              (
                  [pd.NaT, "2011-01-03", "2011-01-05", "2011-01-02", pd.NaT],
                  [pd.NaT, pd.NaT, "2011-01-02", "2011-01-03", "2011-01-05"],
              ),
          ],
      )
      def test_order_without_freq(self, index_dates, expected_dates, tz_naive_fixture):
          tz = tz_naive_fixture
  
          # without freq
          index = DatetimeIndex(index_dates, tz=tz, name="idx")
          expected = DatetimeIndex(expected_dates, tz=tz, name="idx")
  
          ordered = index.sort_values()
          tm.assert_index_equal(ordered, expected)
          assert ordered.freq is None
  
          ordered = index.sort_values(ascending=False)
          tm.assert_index_equal(ordered, expected[::-1])
          assert ordered.freq is None
  
          ordered, indexer = index.sort_values(return_indexer=True)
          tm.assert_index_equal(ordered, expected)
  
          exp = np.array([0, 4, 3, 1, 2])
          tm.assert_numpy_array_equal(indexer, exp, check_dtype=False)
          assert ordered.freq is None
  
          ordered, indexer = index.sort_values(return_indexer=True, ascending=False)
          tm.assert_index_equal(ordered, expected[::-1])
  
          exp = np.array([2, 1, 3, 4, 0])
          tm.assert_numpy_array_equal(indexer, exp, check_dtype=False)
          assert ordered.freq is None
  
      def test_drop_duplicates_metadata(self):
          # GH 10115
          idx = pd.date_range("2011-01-01", "2011-01-31", freq="D", name="idx")
          result = idx.drop_duplicates()
          tm.assert_index_equal(idx, result)
          assert idx.freq == result.freq
  
          idx_dup = idx.append(idx)
          assert idx_dup.freq is None  # freq is reset
          result = idx_dup.drop_duplicates()
          tm.assert_index_equal(idx, result)
          assert result.freq is None
  
      def test_drop_duplicates(self):
          # to check Index/Series compat
          base = pd.date_range("2011-01-01", "2011-01-31", freq="D", name="idx")
          idx = base.append(base[:5])
  
          res = idx.drop_duplicates()
          tm.assert_index_equal(res, base)
          res = Series(idx).drop_duplicates()
          tm.assert_series_equal(res, Series(base))
  
          res = idx.drop_duplicates(keep="last")
          exp = base[5:].append(base[:5])
          tm.assert_index_equal(res, exp)
          res = Series(idx).drop_duplicates(keep="last")
          tm.assert_series_equal(res, Series(exp, index=np.arange(5, 36)))
  
          res = idx.drop_duplicates(keep=False)
          tm.assert_index_equal(res, base[5:])
          res = Series(idx).drop_duplicates(keep=False)
          tm.assert_series_equal(res, Series(base[5:], index=np.arange(5, 31)))
  
      @pytest.mark.parametrize(
          "freq",
          [
              "A",
              "2A",
              "-2A",
              "Q",
              "-1Q",
              "M",
              "-1M",
              "D",
              "3D",
              "-3D",
              "W",
              "-1W",
              "H",
              "2H",
              "-2H",
              "T",
              "2T",
              "S",
              "-3S",
          ],
      )
      def test_infer_freq(self, freq):
          # GH 11018
          idx = pd.date_range("2011-01-01 09:00:00", freq=freq, periods=10)
          result = pd.DatetimeIndex(idx.asi8, freq="infer")
          tm.assert_index_equal(idx, result)
          assert result.freq == freq
  
      def test_nat(self, tz_naive_fixture):
          tz = tz_naive_fixture
          assert pd.DatetimeIndex._na_value is pd.NaT
          assert pd.DatetimeIndex([])._na_value is pd.NaT
  
          idx = pd.DatetimeIndex(["2011-01-01", "2011-01-02"], tz=tz)
          assert idx._can_hold_na
  
          tm.assert_numpy_array_equal(idx._isnan, np.array([False, False]))
          assert idx.hasnans is False
          tm.assert_numpy_array_equal(idx._nan_idxs, np.array([], dtype=np.intp))
  
          idx = pd.DatetimeIndex(["2011-01-01", "NaT"], tz=tz)
          assert idx._can_hold_na
  
          tm.assert_numpy_array_equal(idx._isnan, np.array([False, True]))
          assert idx.hasnans is True
          tm.assert_numpy_array_equal(idx._nan_idxs, np.array([1], dtype=np.intp))
  
      def test_equals(self):
          # GH 13107
          idx = pd.DatetimeIndex(["2011-01-01", "2011-01-02", "NaT"])
          assert idx.equals(idx)
          assert idx.equals(idx.copy())
          assert idx.equals(idx.astype(object))
          assert idx.astype(object).equals(idx)
          assert idx.astype(object).equals(idx.astype(object))
          assert not idx.equals(list(idx))
          assert not idx.equals(pd.Series(idx))
  
          idx2 = pd.DatetimeIndex(["2011-01-01", "2011-01-02", "NaT"], tz="US/Pacific")
          assert not idx.equals(idx2)
          assert not idx.equals(idx2.copy())
          assert not idx.equals(idx2.astype(object))
          assert not idx.astype(object).equals(idx2)
          assert not idx.equals(list(idx2))
          assert not idx.equals(pd.Series(idx2))
  
          # same internal, different tz
          idx3 = pd.DatetimeIndex._simple_new(idx.asi8, tz="US/Pacific")
          tm.assert_numpy_array_equal(idx.asi8, idx3.asi8)
          assert not idx.equals(idx3)
          assert not idx.equals(idx3.copy())
          assert not idx.equals(idx3.astype(object))
          assert not idx.astype(object).equals(idx3)
          assert not idx.equals(list(idx3))
          assert not idx.equals(pd.Series(idx3))
  
      @pytest.mark.parametrize("values", [["20180101", "20180103", "20180105"], []])
      @pytest.mark.parametrize("freq", ["2D", Day(2), "2B", BDay(2), "48H", Hour(48)])
      @pytest.mark.parametrize("tz", [None, "US/Eastern"])
      def test_freq_setter(self, values, freq, tz):
          # GH 20678
          idx = DatetimeIndex(values, tz=tz)
  
          # can set to an offset, converting from string if necessary
          idx.freq = freq
          assert idx.freq == freq
          assert isinstance(idx.freq, ABCDateOffset)
  
          # can reset to None
          idx.freq = None
          assert idx.freq is None
  
      def test_freq_setter_errors(self):
          # GH 20678
          idx = DatetimeIndex(["20180101", "20180103", "20180105"])
  
          # setting with an incompatible freq
          msg = (
              "Inferred frequency 2D from passed values does not conform to "
              "passed frequency 5D"
          )
          with pytest.raises(ValueError, match=msg):
              idx.freq = "5D"
  
          # setting with non-freq string
          with pytest.raises(ValueError, match="Invalid frequency"):
              idx.freq = "foo"
  
      def test_offset_deprecated(self):
          # GH 20716
          idx = pd.DatetimeIndex(["20180101", "20180102"])
  
          # getter deprecated
          with tm.assert_produces_warning(FutureWarning):
              idx.offset
  
          # setter deprecated
          with tm.assert_produces_warning(FutureWarning):
              idx.offset = BDay()
  
  
  class TestBusinessDatetimeIndex:
      def setup_method(self, method):
          self.rng = bdate_range(START, END)
  
      def test_comparison(self):
          d = self.rng[10]
  
          comp = self.rng > d
          assert comp[11]
          assert not comp[9]
  
      def test_pickle_unpickle(self):
          unpickled = tm.round_trip_pickle(self.rng)
          assert unpickled.freq is not None
  
      def test_copy(self):
          cp = self.rng.copy()
          repr(cp)
          tm.assert_index_equal(cp, self.rng)
  
      def test_shift(self):
          shifted = self.rng.shift(5)
          assert shifted[0] == self.rng[5]
          assert shifted.freq == self.rng.freq
  
          shifted = self.rng.shift(-5)
          assert shifted[5] == self.rng[0]
          assert shifted.freq == self.rng.freq
  
          shifted = self.rng.shift(0)
          assert shifted[0] == self.rng[0]
          assert shifted.freq == self.rng.freq
  
          rng = date_range(START, END, freq=BMonthEnd())
          shifted = rng.shift(1, freq=BDay())
          assert shifted[0] == rng[0] + BDay()
  
      def test_equals(self):
          assert not self.rng.equals(list(self.rng))
  
      def test_identical(self):
          t1 = self.rng.copy()
          t2 = self.rng.copy()
          assert t1.identical(t2)
  
          # name
          t1 = t1.rename("foo")
          assert t1.equals(t2)
          assert not t1.identical(t2)
          t2 = t2.rename("foo")
          assert t1.identical(t2)
  
          # freq
          t2v = Index(t2.values)
          assert t1.equals(t2v)
          assert not t1.identical(t2v)
  
  
  class TestCustomDatetimeIndex:
      def setup_method(self, method):
          self.rng = bdate_range(START, END, freq="C")
  
      def test_comparison(self):
          d = self.rng[10]
  
          comp = self.rng > d
          assert comp[11]
          assert not comp[9]
  
      def test_copy(self):
          cp = self.rng.copy()
          repr(cp)
          tm.assert_index_equal(cp, self.rng)
  
      def test_shift(self):
  
          shifted = self.rng.shift(5)
          assert shifted[0] == self.rng[5]
          assert shifted.freq == self.rng.freq
  
          shifted = self.rng.shift(-5)
          assert shifted[5] == self.rng[0]
          assert shifted.freq == self.rng.freq
  
          shifted = self.rng.shift(0)
          assert shifted[0] == self.rng[0]
          assert shifted.freq == self.rng.freq
  
          with warnings.catch_warnings(record=True):
              warnings.simplefilter("ignore", pd.errors.PerformanceWarning)
              rng = date_range(START, END, freq=BMonthEnd())
              shifted = rng.shift(1, freq=CDay())
              assert shifted[0] == rng[0] + CDay()
  
      def test_shift_periods(self):
          # GH#22458 : argument 'n' was deprecated in favor of 'periods'
          idx = pd.date_range(start=START, end=END, periods=3)
          tm.assert_index_equal(idx.shift(periods=0), idx)
          tm.assert_index_equal(idx.shift(0), idx)
          with tm.assert_produces_warning(FutureWarning, check_stacklevel=True):
              tm.assert_index_equal(idx.shift(n=0), idx)
  
      def test_pickle_unpickle(self):
          unpickled = tm.round_trip_pickle(self.rng)
          assert unpickled.freq is not None
  
      def test_equals(self):
          assert not self.rng.equals(list(self.rng))
  