import numpy as np
|
import pytest
|
|
import pandas.util._test_decorators as td
|
|
from pandas import (
|
DataFrame,
|
MultiIndex,
|
)
|
import pandas._testing as tm
|
from pandas.core.arrays import PandasArray
|
|
pytestmark = td.skip_array_manager_invalid_test
|
|
|
class TestToDictOfBlocks:
|
def test_copy_blocks(self, float_frame):
|
# GH#9607
|
df = DataFrame(float_frame, copy=True)
|
column = df.columns[0]
|
|
# use the default copy=True, change a column
|
_last_df = None
|
blocks = df._to_dict_of_blocks(copy=True)
|
for _df in blocks.values():
|
_last_df = _df
|
if column in _df:
|
_df.loc[:, column] = _df[column] + 1
|
|
# make sure we did not change the original DataFrame
|
assert _last_df is not None and not _last_df[column].equals(df[column])
|
|
def test_no_copy_blocks(self, float_frame, using_copy_on_write):
|
# GH#9607
|
df = DataFrame(float_frame, copy=True)
|
column = df.columns[0]
|
|
_last_df = None
|
# use the copy=False, change a column
|
blocks = df._to_dict_of_blocks(copy=False)
|
for _df in blocks.values():
|
_last_df = _df
|
if column in _df:
|
_df.loc[:, column] = _df[column] + 1
|
|
if not using_copy_on_write:
|
# make sure we did change the original DataFrame
|
assert _last_df is not None and _last_df[column].equals(df[column])
|
else:
|
assert _last_df is not None and not _last_df[column].equals(df[column])
|
|
|
def test_to_dict_of_blocks_item_cache(request, using_copy_on_write):
|
if using_copy_on_write:
|
request.node.add_marker(pytest.mark.xfail(reason="CoW - not yet implemented"))
|
# Calling to_dict_of_blocks should not poison item_cache
|
df = DataFrame({"a": [1, 2, 3, 4], "b": ["a", "b", "c", "d"]})
|
df["c"] = PandasArray(np.array([1, 2, None, 3], dtype=object))
|
mgr = df._mgr
|
assert len(mgr.blocks) == 3 # i.e. not consolidated
|
|
ser = df["b"] # populations item_cache["b"]
|
|
df._to_dict_of_blocks()
|
|
if using_copy_on_write:
|
# TODO(CoW) we should disallow this, so `df` doesn't get updated,
|
# this currently still updates df, so this test fails
|
ser.values[0] = "foo"
|
assert df.loc[0, "b"] == "a"
|
else:
|
# Check that the to_dict_of_blocks didn't break link between ser and df
|
ser.values[0] = "foo"
|
assert df.loc[0, "b"] == "foo"
|
|
assert df["b"] is ser
|
|
|
def test_set_change_dtype_slice():
|
# GH#8850
|
cols = MultiIndex.from_tuples([("1st", "a"), ("2nd", "b"), ("3rd", "c")])
|
df = DataFrame([[1.0, 2, 3], [4.0, 5, 6]], columns=cols)
|
df["2nd"] = df["2nd"] * 2.0
|
|
blocks = df._to_dict_of_blocks()
|
assert sorted(blocks.keys()) == ["float64", "int64"]
|
tm.assert_frame_equal(
|
blocks["float64"], DataFrame([[1.0, 4.0], [4.0, 10.0]], columns=cols[:2])
|
)
|
tm.assert_frame_equal(blocks["int64"], DataFrame([[3], [6]], columns=cols[2:]))
|
