projektAI/venv/Lib/site-packages/pandas/tests/series/methods/test_diff.py
2021-06-06 22:13:05 +02:00

78 lines
2.3 KiB
Python

import numpy as np
import pytest
from pandas import Series, TimedeltaIndex, date_range
import pandas._testing as tm
class TestSeriesDiff:
def test_diff_np(self):
pytest.skip("skipping due to Series no longer being an ndarray")
# no longer works as the return type of np.diff is now nd.array
s = Series(np.arange(5))
r = np.diff(s)
tm.assert_series_equal(Series([np.nan, 0, 0, 0, np.nan]), r)
def test_diff_int(self):
# int dtype
a = 10000000000000000
b = a + 1
s = Series([a, b])
result = s.diff()
assert result[1] == 1
def test_diff_tz(self):
# Combined datetime diff, normal diff and boolean diff test
ts = tm.makeTimeSeries(name="ts")
ts.diff()
# neg n
result = ts.diff(-1)
expected = ts - ts.shift(-1)
tm.assert_series_equal(result, expected)
# 0
result = ts.diff(0)
expected = ts - ts
tm.assert_series_equal(result, expected)
# datetime diff (GH#3100)
s = Series(date_range("20130102", periods=5))
result = s.diff()
expected = s - s.shift(1)
tm.assert_series_equal(result, expected)
# timedelta diff
result = result - result.shift(1) # previous result
expected = expected.diff() # previously expected
tm.assert_series_equal(result, expected)
# with tz
s = Series(
date_range("2000-01-01 09:00:00", periods=5, tz="US/Eastern"), name="foo"
)
result = s.diff()
expected = Series(TimedeltaIndex(["NaT"] + ["1 days"] * 4), name="foo")
tm.assert_series_equal(result, expected)
@pytest.mark.parametrize(
"input,output,diff",
[([False, True, True, False, False], [np.nan, True, False, True, False], 1)],
)
def test_diff_bool(self, input, output, diff):
# boolean series (test for fixing #17294)
s = Series(input)
result = s.diff()
expected = Series(output)
tm.assert_series_equal(result, expected)
def test_diff_object_dtype(self):
# object series
s = Series([False, True, 5.0, np.nan, True, False])
result = s.diff()
expected = s - s.shift(1)
tm.assert_series_equal(result, expected)