Inzynierka/Lib/site-packages/pandas/tests/apply/test_frame_transform.py
2023-06-02 12:51:02 +02:00

243 lines
7.3 KiB
Python

import numpy as np
import pytest
from pandas import (
DataFrame,
MultiIndex,
Series,
)
import pandas._testing as tm
from pandas.tests.apply.common import frame_transform_kernels
from pandas.tests.frame.common import zip_frames
def unpack_obj(obj, klass, axis):
"""
Helper to ensure we have the right type of object for a test parametrized
over frame_or_series.
"""
if klass is not DataFrame:
obj = obj["A"]
if axis != 0:
pytest.skip(f"Test is only for DataFrame with axis={axis}")
return obj
def test_transform_ufunc(axis, float_frame, frame_or_series):
# GH 35964
obj = unpack_obj(float_frame, frame_or_series, axis)
with np.errstate(all="ignore"):
f_sqrt = np.sqrt(obj)
# ufunc
result = obj.transform(np.sqrt, axis=axis)
expected = f_sqrt
tm.assert_equal(result, expected)
@pytest.mark.parametrize(
"ops, names",
[
([np.sqrt], ["sqrt"]),
([np.abs, np.sqrt], ["absolute", "sqrt"]),
(np.array([np.sqrt]), ["sqrt"]),
(np.array([np.abs, np.sqrt]), ["absolute", "sqrt"]),
],
)
def test_transform_listlike(axis, float_frame, ops, names):
# GH 35964
other_axis = 1 if axis in {0, "index"} else 0
with np.errstate(all="ignore"):
expected = zip_frames([op(float_frame) for op in ops], axis=other_axis)
if axis in {0, "index"}:
expected.columns = MultiIndex.from_product([float_frame.columns, names])
else:
expected.index = MultiIndex.from_product([float_frame.index, names])
result = float_frame.transform(ops, axis=axis)
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize("ops", [[], np.array([])])
def test_transform_empty_listlike(float_frame, ops, frame_or_series):
obj = unpack_obj(float_frame, frame_or_series, 0)
with pytest.raises(ValueError, match="No transform functions were provided"):
obj.transform(ops)
@pytest.mark.parametrize("box", [dict, Series])
def test_transform_dictlike(axis, float_frame, box):
# GH 35964
if axis in (0, "index"):
e = float_frame.columns[0]
expected = float_frame[[e]].transform(np.abs)
else:
e = float_frame.index[0]
expected = float_frame.iloc[[0]].transform(np.abs)
result = float_frame.transform(box({e: np.abs}), axis=axis)
tm.assert_frame_equal(result, expected)
def test_transform_dictlike_mixed():
# GH 40018 - mix of lists and non-lists in values of a dictionary
df = DataFrame({"a": [1, 2], "b": [1, 4], "c": [1, 4]})
result = df.transform({"b": ["sqrt", "abs"], "c": "sqrt"})
expected = DataFrame(
[[1.0, 1, 1.0], [2.0, 4, 2.0]],
columns=MultiIndex([("b", "c"), ("sqrt", "abs")], [(0, 0, 1), (0, 1, 0)]),
)
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
"ops",
[
{},
{"A": []},
{"A": [], "B": "cumsum"},
{"A": "cumsum", "B": []},
{"A": [], "B": ["cumsum"]},
{"A": ["cumsum"], "B": []},
],
)
def test_transform_empty_dictlike(float_frame, ops, frame_or_series):
obj = unpack_obj(float_frame, frame_or_series, 0)
with pytest.raises(ValueError, match="No transform functions were provided"):
obj.transform(ops)
@pytest.mark.parametrize("use_apply", [True, False])
def test_transform_udf(axis, float_frame, use_apply, frame_or_series):
# GH 35964
obj = unpack_obj(float_frame, frame_or_series, axis)
# transform uses UDF either via apply or passing the entire DataFrame
def func(x):
# transform is using apply iff x is not a DataFrame
if use_apply == isinstance(x, frame_or_series):
# Force transform to fallback
raise ValueError
return x + 1
result = obj.transform(func, axis=axis)
expected = obj + 1
tm.assert_equal(result, expected)
wont_fail = ["ffill", "bfill", "fillna", "pad", "backfill", "shift"]
frame_kernels_raise = [x for x in frame_transform_kernels if x not in wont_fail]
@pytest.mark.parametrize("op", [*frame_kernels_raise, lambda x: x + 1])
def test_transform_bad_dtype(op, frame_or_series, request):
# GH 35964
if op == "ngroup":
request.node.add_marker(
pytest.mark.xfail(raises=ValueError, reason="ngroup not valid for NDFrame")
)
obj = DataFrame({"A": 3 * [object]}) # DataFrame that will fail on most transforms
obj = tm.get_obj(obj, frame_or_series)
error = TypeError
msg = "|".join(
[
"not supported between instances of 'type' and 'type'",
"unsupported operand type",
]
)
with pytest.raises(error, match=msg):
obj.transform(op)
with pytest.raises(error, match=msg):
obj.transform([op])
with pytest.raises(error, match=msg):
obj.transform({"A": op})
with pytest.raises(error, match=msg):
obj.transform({"A": [op]})
@pytest.mark.parametrize("op", frame_kernels_raise)
def test_transform_failure_typeerror(request, op):
# GH 35964
if op == "ngroup":
request.node.add_marker(
pytest.mark.xfail(raises=ValueError, reason="ngroup not valid for NDFrame")
)
# Using object makes most transform kernels fail
df = DataFrame({"A": 3 * [object], "B": [1, 2, 3]})
error = TypeError
msg = "|".join(
[
"not supported between instances of 'type' and 'type'",
"unsupported operand type",
]
)
with pytest.raises(error, match=msg):
df.transform([op])
with pytest.raises(error, match=msg):
df.transform({"A": op, "B": op})
with pytest.raises(error, match=msg):
df.transform({"A": [op], "B": [op]})
with pytest.raises(error, match=msg):
df.transform({"A": [op, "shift"], "B": [op]})
def test_transform_failure_valueerror():
# GH 40211
def op(x):
if np.sum(np.sum(x)) < 10:
raise ValueError
return x
df = DataFrame({"A": [1, 2, 3], "B": [400, 500, 600]})
msg = "Transform function failed"
with pytest.raises(ValueError, match=msg):
df.transform([op])
with pytest.raises(ValueError, match=msg):
df.transform({"A": op, "B": op})
with pytest.raises(ValueError, match=msg):
df.transform({"A": [op], "B": [op]})
with pytest.raises(ValueError, match=msg):
df.transform({"A": [op, "shift"], "B": [op]})
@pytest.mark.parametrize("use_apply", [True, False])
def test_transform_passes_args(use_apply, frame_or_series):
# GH 35964
# transform uses UDF either via apply or passing the entire DataFrame
expected_args = [1, 2]
expected_kwargs = {"c": 3}
def f(x, a, b, c):
# transform is using apply iff x is not a DataFrame
if use_apply == isinstance(x, frame_or_series):
# Force transform to fallback
raise ValueError
assert [a, b] == expected_args
assert c == expected_kwargs["c"]
return x
frame_or_series([1]).transform(f, 0, *expected_args, **expected_kwargs)
def test_transform_empty_dataframe():
# https://github.com/pandas-dev/pandas/issues/39636
df = DataFrame([], columns=["col1", "col2"])
result = df.transform(lambda x: x + 10)
tm.assert_frame_equal(result, df)
result = df["col1"].transform(lambda x: x + 10)
tm.assert_series_equal(result, df["col1"])