Inzynierka/Lib/site-packages/pandas/tests/indexes/datetimes/methods/test_shift.py
2023-06-02 12:51:02 +02:00

163 lines
5.3 KiB
Python

from datetime import datetime
import pytest
import pytz
from pandas.errors import NullFrequencyError
import pandas as pd
from pandas import (
DatetimeIndex,
Series,
date_range,
)
import pandas._testing as tm
START, END = datetime(2009, 1, 1), datetime(2010, 1, 1)
class TestDatetimeIndexShift:
# -------------------------------------------------------------
# DatetimeIndex.shift is used in integer addition
def test_dti_shift_tzaware(self, tz_naive_fixture):
# GH#9903
tz = tz_naive_fixture
idx = DatetimeIndex([], name="xxx", tz=tz)
tm.assert_index_equal(idx.shift(0, freq="H"), idx)
tm.assert_index_equal(idx.shift(3, freq="H"), idx)
idx = DatetimeIndex(
["2011-01-01 10:00", "2011-01-01 11:00", "2011-01-01 12:00"],
name="xxx",
tz=tz,
freq="H",
)
tm.assert_index_equal(idx.shift(0, freq="H"), idx)
exp = DatetimeIndex(
["2011-01-01 13:00", "2011-01-01 14:00", "2011-01-01 15:00"],
name="xxx",
tz=tz,
freq="H",
)
tm.assert_index_equal(idx.shift(3, freq="H"), exp)
exp = DatetimeIndex(
["2011-01-01 07:00", "2011-01-01 08:00", "2011-01-01 09:00"],
name="xxx",
tz=tz,
freq="H",
)
tm.assert_index_equal(idx.shift(-3, freq="H"), exp)
def test_dti_shift_freqs(self):
# test shift for DatetimeIndex and non DatetimeIndex
# GH#8083
drange = date_range("20130101", periods=5)
result = drange.shift(1)
expected = DatetimeIndex(
["2013-01-02", "2013-01-03", "2013-01-04", "2013-01-05", "2013-01-06"],
freq="D",
)
tm.assert_index_equal(result, expected)
result = drange.shift(-1)
expected = DatetimeIndex(
["2012-12-31", "2013-01-01", "2013-01-02", "2013-01-03", "2013-01-04"],
freq="D",
)
tm.assert_index_equal(result, expected)
result = drange.shift(3, freq="2D")
expected = DatetimeIndex(
["2013-01-07", "2013-01-08", "2013-01-09", "2013-01-10", "2013-01-11"],
freq="D",
)
tm.assert_index_equal(result, expected)
def test_dti_shift_int(self):
rng = date_range("1/1/2000", periods=20)
result = rng + 5 * rng.freq
expected = rng.shift(5)
tm.assert_index_equal(result, expected)
result = rng - 5 * rng.freq
expected = rng.shift(-5)
tm.assert_index_equal(result, expected)
def test_dti_shift_no_freq(self):
# GH#19147
dti = DatetimeIndex(["2011-01-01 10:00", "2011-01-01"], freq=None)
with pytest.raises(NullFrequencyError, match="Cannot shift with no freq"):
dti.shift(2)
@pytest.mark.parametrize("tzstr", ["US/Eastern", "dateutil/US/Eastern"])
def test_dti_shift_localized(self, tzstr):
dr = date_range("2011/1/1", "2012/1/1", freq="W-FRI")
dr_tz = dr.tz_localize(tzstr)
result = dr_tz.shift(1, "10T")
assert result.tz == dr_tz.tz
def test_dti_shift_across_dst(self):
# GH 8616
idx = date_range("2013-11-03", tz="America/Chicago", periods=7, freq="H")
s = Series(index=idx[:-1], dtype=object)
result = s.shift(freq="H")
expected = Series(index=idx[1:], dtype=object)
tm.assert_series_equal(result, expected)
@pytest.mark.parametrize(
"shift, result_time",
[
[0, "2014-11-14 00:00:00"],
[-1, "2014-11-13 23:00:00"],
[1, "2014-11-14 01:00:00"],
],
)
def test_dti_shift_near_midnight(self, shift, result_time):
# GH 8616
dt = datetime(2014, 11, 14, 0)
dt_est = pytz.timezone("EST").localize(dt)
s = Series(data=[1], index=[dt_est])
result = s.shift(shift, freq="H")
expected = Series(1, index=DatetimeIndex([result_time], tz="EST"))
tm.assert_series_equal(result, expected)
def test_shift_periods(self):
# GH#22458 : argument 'n' was deprecated in favor of 'periods'
idx = 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)
@pytest.mark.parametrize("freq", ["B", "C"])
def test_shift_bday(self, freq):
rng = date_range(START, END, freq=freq)
shifted = rng.shift(5)
assert shifted[0] == rng[5]
assert shifted.freq == rng.freq
shifted = rng.shift(-5)
assert shifted[5] == rng[0]
assert shifted.freq == rng.freq
shifted = rng.shift(0)
assert shifted[0] == rng[0]
assert shifted.freq == rng.freq
def test_shift_bmonth(self):
rng = date_range(START, END, freq=pd.offsets.BMonthEnd())
shifted = rng.shift(1, freq=pd.offsets.BDay())
assert shifted[0] == rng[0] + pd.offsets.BDay()
rng = date_range(START, END, freq=pd.offsets.BMonthEnd())
with tm.assert_produces_warning(pd.errors.PerformanceWarning):
shifted = rng.shift(1, freq=pd.offsets.CDay())
assert shifted[0] == rng[0] + pd.offsets.CDay()
def test_shift_empty(self):
# GH#14811
dti = date_range(start="2016-10-21", end="2016-10-21", freq="BM")
result = dti.shift(1)
tm.assert_index_equal(result, dti)