projektAI/venv/Lib/site-packages/pandas/tests/frame/methods/test_shift.py

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2021-06-06 22:13:05 +02:00
import numpy as np
import pytest
import pandas as pd
from pandas import CategoricalIndex, DataFrame, Index, Series, date_range, offsets
import pandas._testing as tm
class TestDataFrameShift:
def test_shift(self, datetime_frame, int_frame):
# naive shift
shiftedFrame = datetime_frame.shift(5)
tm.assert_index_equal(shiftedFrame.index, datetime_frame.index)
shiftedSeries = datetime_frame["A"].shift(5)
tm.assert_series_equal(shiftedFrame["A"], shiftedSeries)
shiftedFrame = datetime_frame.shift(-5)
tm.assert_index_equal(shiftedFrame.index, datetime_frame.index)
shiftedSeries = datetime_frame["A"].shift(-5)
tm.assert_series_equal(shiftedFrame["A"], shiftedSeries)
# shift by 0
unshifted = datetime_frame.shift(0)
tm.assert_frame_equal(unshifted, datetime_frame)
# shift by DateOffset
shiftedFrame = datetime_frame.shift(5, freq=offsets.BDay())
assert len(shiftedFrame) == len(datetime_frame)
shiftedFrame2 = datetime_frame.shift(5, freq="B")
tm.assert_frame_equal(shiftedFrame, shiftedFrame2)
d = datetime_frame.index[0]
shifted_d = d + offsets.BDay(5)
tm.assert_series_equal(
datetime_frame.xs(d), shiftedFrame.xs(shifted_d), check_names=False
)
# shift int frame
int_shifted = int_frame.shift(1) # noqa
# Shifting with PeriodIndex
ps = tm.makePeriodFrame()
shifted = ps.shift(1)
unshifted = shifted.shift(-1)
tm.assert_index_equal(shifted.index, ps.index)
tm.assert_index_equal(unshifted.index, ps.index)
tm.assert_numpy_array_equal(
unshifted.iloc[:, 0].dropna().values, ps.iloc[:-1, 0].values
)
shifted2 = ps.shift(1, "B")
shifted3 = ps.shift(1, offsets.BDay())
tm.assert_frame_equal(shifted2, shifted3)
tm.assert_frame_equal(ps, shifted2.shift(-1, "B"))
msg = "does not match PeriodIndex freq"
with pytest.raises(ValueError, match=msg):
ps.shift(freq="D")
# shift other axis
# GH#6371
df = DataFrame(np.random.rand(10, 5))
expected = pd.concat(
[DataFrame(np.nan, index=df.index, columns=[0]), df.iloc[:, 0:-1]],
ignore_index=True,
axis=1,
)
result = df.shift(1, axis=1)
tm.assert_frame_equal(result, expected)
# shift named axis
df = DataFrame(np.random.rand(10, 5))
expected = pd.concat(
[DataFrame(np.nan, index=df.index, columns=[0]), df.iloc[:, 0:-1]],
ignore_index=True,
axis=1,
)
result = df.shift(1, axis="columns")
tm.assert_frame_equal(result, expected)
def test_shift_bool(self):
df = DataFrame({"high": [True, False], "low": [False, False]})
rs = df.shift(1)
xp = DataFrame(
np.array([[np.nan, np.nan], [True, False]], dtype=object),
columns=["high", "low"],
)
tm.assert_frame_equal(rs, xp)
def test_shift_categorical(self):
# GH#9416
s1 = Series(["a", "b", "c"], dtype="category")
s2 = Series(["A", "B", "C"], dtype="category")
df = DataFrame({"one": s1, "two": s2})
rs = df.shift(1)
xp = DataFrame({"one": s1.shift(1), "two": s2.shift(1)})
tm.assert_frame_equal(rs, xp)
def test_shift_fill_value(self):
# GH#24128
df = DataFrame(
[1, 2, 3, 4, 5], index=date_range("1/1/2000", periods=5, freq="H")
)
exp = DataFrame(
[0, 1, 2, 3, 4], index=date_range("1/1/2000", periods=5, freq="H")
)
result = df.shift(1, fill_value=0)
tm.assert_frame_equal(result, exp)
exp = DataFrame(
[0, 0, 1, 2, 3], index=date_range("1/1/2000", periods=5, freq="H")
)
result = df.shift(2, fill_value=0)
tm.assert_frame_equal(result, exp)
def test_shift_empty(self):
# Regression test for GH#8019
df = DataFrame({"foo": []})
rs = df.shift(-1)
tm.assert_frame_equal(df, rs)
def test_shift_duplicate_columns(self):
# GH#9092; verify that position-based shifting works
# in the presence of duplicate columns
column_lists = [list(range(5)), [1] * 5, [1, 1, 2, 2, 1]]
data = np.random.randn(20, 5)
shifted = []
for columns in column_lists:
df = DataFrame(data.copy(), columns=columns)
for s in range(5):
df.iloc[:, s] = df.iloc[:, s].shift(s + 1)
df.columns = range(5)
shifted.append(df)
# sanity check the base case
nulls = shifted[0].isna().sum()
tm.assert_series_equal(nulls, Series(range(1, 6), dtype="int64"))
# check all answers are the same
tm.assert_frame_equal(shifted[0], shifted[1])
tm.assert_frame_equal(shifted[0], shifted[2])
def test_shift_axis1_multiple_blocks(self):
# GH#35488
df1 = DataFrame(np.random.randint(1000, size=(5, 3)))
df2 = DataFrame(np.random.randint(1000, size=(5, 2)))
df3 = pd.concat([df1, df2], axis=1)
assert len(df3._mgr.blocks) == 2
result = df3.shift(2, axis=1)
expected = df3.take([-1, -1, 0, 1, 2], axis=1)
expected.iloc[:, :2] = np.nan
expected.columns = df3.columns
tm.assert_frame_equal(result, expected)
# Case with periods < 0
# rebuild df3 because `take` call above consolidated
df3 = pd.concat([df1, df2], axis=1)
assert len(df3._mgr.blocks) == 2
result = df3.shift(-2, axis=1)
expected = df3.take([2, 3, 4, -1, -1], axis=1)
expected.iloc[:, -2:] = np.nan
expected.columns = df3.columns
tm.assert_frame_equal(result, expected)
@pytest.mark.filterwarnings("ignore:tshift is deprecated:FutureWarning")
def test_tshift(self, datetime_frame):
# TODO: remove this test when tshift deprecation is enforced
# PeriodIndex
ps = tm.makePeriodFrame()
shifted = ps.tshift(1)
unshifted = shifted.tshift(-1)
tm.assert_frame_equal(unshifted, ps)
shifted2 = ps.tshift(freq="B")
tm.assert_frame_equal(shifted, shifted2)
shifted3 = ps.tshift(freq=offsets.BDay())
tm.assert_frame_equal(shifted, shifted3)
msg = "Given freq M does not match PeriodIndex freq B"
with pytest.raises(ValueError, match=msg):
ps.tshift(freq="M")
# DatetimeIndex
shifted = datetime_frame.tshift(1)
unshifted = shifted.tshift(-1)
tm.assert_frame_equal(datetime_frame, unshifted)
shifted2 = datetime_frame.tshift(freq=datetime_frame.index.freq)
tm.assert_frame_equal(shifted, shifted2)
inferred_ts = DataFrame(
datetime_frame.values,
Index(np.asarray(datetime_frame.index)),
columns=datetime_frame.columns,
)
shifted = inferred_ts.tshift(1)
expected = datetime_frame.tshift(1)
expected.index = expected.index._with_freq(None)
tm.assert_frame_equal(shifted, expected)
unshifted = shifted.tshift(-1)
tm.assert_frame_equal(unshifted, inferred_ts)
no_freq = datetime_frame.iloc[[0, 5, 7], :]
msg = "Freq was not set in the index hence cannot be inferred"
with pytest.raises(ValueError, match=msg):
no_freq.tshift()
def test_tshift_deprecated(self, datetime_frame):
# GH#11631
with tm.assert_produces_warning(FutureWarning):
datetime_frame.tshift()
def test_period_index_frame_shift_with_freq(self):
ps = tm.makePeriodFrame()
shifted = ps.shift(1, freq="infer")
unshifted = shifted.shift(-1, freq="infer")
tm.assert_frame_equal(unshifted, ps)
shifted2 = ps.shift(freq="B")
tm.assert_frame_equal(shifted, shifted2)
shifted3 = ps.shift(freq=offsets.BDay())
tm.assert_frame_equal(shifted, shifted3)
def test_datetime_frame_shift_with_freq(self, datetime_frame):
shifted = datetime_frame.shift(1, freq="infer")
unshifted = shifted.shift(-1, freq="infer")
tm.assert_frame_equal(datetime_frame, unshifted)
shifted2 = datetime_frame.shift(freq=datetime_frame.index.freq)
tm.assert_frame_equal(shifted, shifted2)
inferred_ts = DataFrame(
datetime_frame.values,
Index(np.asarray(datetime_frame.index)),
columns=datetime_frame.columns,
)
shifted = inferred_ts.shift(1, freq="infer")
expected = datetime_frame.shift(1, freq="infer")
expected.index = expected.index._with_freq(None)
tm.assert_frame_equal(shifted, expected)
unshifted = shifted.shift(-1, freq="infer")
tm.assert_frame_equal(unshifted, inferred_ts)
def test_period_index_frame_shift_with_freq_error(self):
ps = tm.makePeriodFrame()
msg = "Given freq M does not match PeriodIndex freq B"
with pytest.raises(ValueError, match=msg):
ps.shift(freq="M")
def test_datetime_frame_shift_with_freq_error(self, datetime_frame):
no_freq = datetime_frame.iloc[[0, 5, 7], :]
msg = "Freq was not set in the index hence cannot be inferred"
with pytest.raises(ValueError, match=msg):
no_freq.shift(freq="infer")
def test_shift_dt64values_int_fill_deprecated(self):
# GH#31971
ser = Series([pd.Timestamp("2020-01-01"), pd.Timestamp("2020-01-02")])
df = ser.to_frame()
with tm.assert_produces_warning(FutureWarning):
result = df.shift(1, fill_value=0)
expected = Series([pd.Timestamp(0), ser[0]]).to_frame()
tm.assert_frame_equal(result, expected)
# axis = 1
df2 = DataFrame({"A": ser, "B": ser})
df2._consolidate_inplace()
with tm.assert_produces_warning(FutureWarning):
result = df2.shift(1, axis=1, fill_value=0)
expected = DataFrame({"A": [pd.Timestamp(0), pd.Timestamp(0)], "B": df2["A"]})
tm.assert_frame_equal(result, expected)
def test_shift_axis1_categorical_columns(self):
# GH#38434
ci = CategoricalIndex(["a", "b", "c"])
df = DataFrame(
{"a": [1, 3], "b": [2, 4], "c": [5, 6]}, index=ci[:-1], columns=ci
)
result = df.shift(axis=1)
expected = DataFrame(
{"a": [np.nan, np.nan], "b": [1, 3], "c": [2, 4]}, index=ci[:-1], columns=ci
)
tm.assert_frame_equal(result, expected)
# periods != 1
result = df.shift(2, axis=1)
expected = DataFrame(
{"a": [np.nan, np.nan], "b": [np.nan, np.nan], "c": [1, 3]},
index=ci[:-1],
columns=ci,
)
tm.assert_frame_equal(result, expected)