projektAI/venv/Lib/site-packages/pandas/tests/groupby/test_groupby_shift_diff.py

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2021-06-06 22:13:05 +02:00
import numpy as np
import pytest
from pandas import DataFrame, NaT, Series, Timedelta, Timestamp
import pandas._testing as tm
def test_group_shift_with_null_key():
# This test is designed to replicate the segfault in issue #13813.
n_rows = 1200
# Generate a moderately large dataframe with occasional missing
# values in column `B`, and then group by [`A`, `B`]. This should
# force `-1` in `labels` array of `g.grouper.group_info` exactly
# at those places, where the group-by key is partially missing.
df = DataFrame(
[(i % 12, i % 3 if i % 3 else np.nan, i) for i in range(n_rows)],
dtype=float,
columns=["A", "B", "Z"],
index=None,
)
g = df.groupby(["A", "B"])
expected = DataFrame(
[(i + 12 if i % 3 and i < n_rows - 12 else np.nan) for i in range(n_rows)],
dtype=float,
columns=["Z"],
index=None,
)
result = g.shift(-1)
tm.assert_frame_equal(result, expected)
def test_group_shift_with_fill_value():
# GH #24128
n_rows = 24
df = DataFrame(
[(i % 12, i % 3, i) for i in range(n_rows)],
dtype=float,
columns=["A", "B", "Z"],
index=None,
)
g = df.groupby(["A", "B"])
expected = DataFrame(
[(i + 12 if i < n_rows - 12 else 0) for i in range(n_rows)],
dtype=float,
columns=["Z"],
index=None,
)
result = g.shift(-1, fill_value=0)[["Z"]]
tm.assert_frame_equal(result, expected)
def test_group_shift_lose_timezone():
# GH 30134
now_dt = Timestamp.utcnow()
df = DataFrame({"a": [1, 1], "date": now_dt})
result = df.groupby("a").shift(0).iloc[0]
expected = Series({"date": now_dt}, name=result.name)
tm.assert_series_equal(result, expected)
def test_group_diff_real(any_real_dtype):
df = DataFrame({"a": [1, 2, 3, 3, 2], "b": [1, 2, 3, 4, 5]}, dtype=any_real_dtype)
result = df.groupby("a")["b"].diff()
exp_dtype = "float"
if any_real_dtype in ["int8", "int16", "float32"]:
exp_dtype = "float32"
expected = Series([np.nan, np.nan, np.nan, 1.0, 3.0], dtype=exp_dtype, name="b")
tm.assert_series_equal(result, expected)
@pytest.mark.parametrize(
"data",
[
[
Timestamp("2013-01-01"),
Timestamp("2013-01-02"),
Timestamp("2013-01-03"),
],
[Timedelta("5 days"), Timedelta("6 days"), Timedelta("7 days")],
],
)
def test_group_diff_datetimelike(data):
df = DataFrame({"a": [1, 2, 2], "b": data})
result = df.groupby("a")["b"].diff()
expected = Series([NaT, NaT, Timedelta("1 days")], name="b")
tm.assert_series_equal(result, expected)
def test_group_diff_bool():
df = DataFrame({"a": [1, 2, 3, 3, 2], "b": [True, True, False, False, True]})
result = df.groupby("a")["b"].diff()
expected = Series([np.nan, np.nan, np.nan, False, False], name="b")
tm.assert_series_equal(result, expected)
def test_group_diff_object_raises(object_dtype):
df = DataFrame(
{"a": ["foo", "bar", "bar"], "b": ["baz", "foo", "foo"]}, dtype=object_dtype
)
with pytest.raises(TypeError, match=r"unsupported operand type\(s\) for -"):
df.groupby("a")["b"].diff()