aoc-2022/venv/Lib/site-packages/pandas/tests/frame/methods/test_transpose.py

119 lines
3.7 KiB
Python

import numpy as np
import pytest
import pandas.util._test_decorators as td
from pandas import (
DataFrame,
DatetimeIndex,
date_range,
)
import pandas._testing as tm
class TestTranspose:
def test_transpose_empty_preserves_datetimeindex(self):
# GH#41382
df = DataFrame(index=DatetimeIndex([]))
expected = DatetimeIndex([], dtype="datetime64[ns]", freq=None)
result1 = df.T.sum().index
result2 = df.sum(axis=1).index
tm.assert_index_equal(result1, expected)
tm.assert_index_equal(result2, expected)
def test_transpose_tzaware_1col_single_tz(self):
# GH#26825
dti = date_range("2016-04-05 04:30", periods=3, tz="UTC")
df = DataFrame(dti)
assert (df.dtypes == dti.dtype).all()
res = df.T
assert (res.dtypes == dti.dtype).all()
def test_transpose_tzaware_2col_single_tz(self):
# GH#26825
dti = date_range("2016-04-05 04:30", periods=3, tz="UTC")
df3 = DataFrame({"A": dti, "B": dti})
assert (df3.dtypes == dti.dtype).all()
res3 = df3.T
assert (res3.dtypes == dti.dtype).all()
def test_transpose_tzaware_2col_mixed_tz(self):
# GH#26825
dti = date_range("2016-04-05 04:30", periods=3, tz="UTC")
dti2 = dti.tz_convert("US/Pacific")
df4 = DataFrame({"A": dti, "B": dti2})
assert (df4.dtypes == [dti.dtype, dti2.dtype]).all()
assert (df4.T.dtypes == object).all()
tm.assert_frame_equal(df4.T.T, df4)
@pytest.mark.parametrize("tz", [None, "America/New_York"])
def test_transpose_preserves_dtindex_equality_with_dst(self, tz):
# GH#19970
idx = date_range("20161101", "20161130", freq="4H", tz=tz)
df = DataFrame({"a": range(len(idx)), "b": range(len(idx))}, index=idx)
result = df.T == df.T
expected = DataFrame(True, index=list("ab"), columns=idx)
tm.assert_frame_equal(result, expected)
def test_transpose_object_to_tzaware_mixed_tz(self):
# GH#26825
dti = date_range("2016-04-05 04:30", periods=3, tz="UTC")
dti2 = dti.tz_convert("US/Pacific")
# mixed all-tzaware dtypes
df2 = DataFrame([dti, dti2])
assert (df2.dtypes == object).all()
res2 = df2.T
assert (res2.dtypes == [dti.dtype, dti2.dtype]).all()
def test_transpose_uint64(self, uint64_frame):
result = uint64_frame.T
expected = DataFrame(uint64_frame.values.T)
expected.index = ["A", "B"]
tm.assert_frame_equal(result, expected)
def test_transpose_float(self, float_frame):
frame = float_frame
dft = frame.T
for idx, series in dft.items():
for col, value in series.items():
if np.isnan(value):
assert np.isnan(frame[col][idx])
else:
assert value == frame[col][idx]
# mixed type
index, data = tm.getMixedTypeDict()
mixed = DataFrame(data, index=index)
mixed_T = mixed.T
for col, s in mixed_T.items():
assert s.dtype == np.object_
@td.skip_array_manager_invalid_test
def test_transpose_get_view(self, float_frame):
dft = float_frame.T
dft.values[:, 5:10] = 5
assert (float_frame.values[5:10] == 5).all()
@td.skip_array_manager_invalid_test
def test_transpose_get_view_dt64tzget_view(self):
dti = date_range("2016-01-01", periods=6, tz="US/Pacific")
arr = dti._data.reshape(3, 2)
df = DataFrame(arr)
assert df._mgr.nblocks == 1
result = df.T
assert result._mgr.nblocks == 1
rtrip = result._mgr.blocks[0].values
assert np.shares_memory(arr._ndarray, rtrip._ndarray)