import numpy as np
|
import pytest
|
|
import pandas.util._test_decorators as td
|
|
import pandas as pd
|
from pandas import (
|
DataFrame,
|
Series,
|
)
|
import pandas._testing as tm
|
from pandas.tests.copy_view.util import get_array
|
|
|
@td.skip_array_manager_invalid_test
|
def test_consolidate(using_copy_on_write):
|
# create unconsolidated DataFrame
|
df = DataFrame({"a": [1, 2, 3], "b": [0.1, 0.2, 0.3]})
|
df["c"] = [4, 5, 6]
|
|
# take a viewing subset
|
subset = df[:]
|
|
# each block of subset references a block of df
|
assert all(blk.refs.has_reference() for blk in subset._mgr.blocks)
|
|
# consolidate the two int64 blocks
|
subset._consolidate_inplace()
|
|
# the float64 block still references the parent one because it still a view
|
assert subset._mgr.blocks[0].refs.has_reference()
|
# equivalent of assert np.shares_memory(df["b"].values, subset["b"].values)
|
# but avoids caching df["b"]
|
assert np.shares_memory(get_array(df, "b"), get_array(subset, "b"))
|
|
# the new consolidated int64 block does not reference another
|
assert not subset._mgr.blocks[1].refs.has_reference()
|
|
# the parent dataframe now also only is linked for the float column
|
assert not df._mgr.blocks[0].refs.has_reference()
|
assert df._mgr.blocks[1].refs.has_reference()
|
assert not df._mgr.blocks[2].refs.has_reference()
|
|
# and modifying subset still doesn't modify parent
|
if using_copy_on_write:
|
subset.iloc[0, 1] = 0.0
|
assert not df._mgr.blocks[1].refs.has_reference()
|
assert df.loc[0, "b"] == 0.1
|
|
|
@pytest.mark.single_cpu
|
@td.skip_array_manager_invalid_test
|
def test_switch_options():
|
# ensure we can switch the value of the option within one session
|
# (assuming data is constructed after switching)
|
|
# using the option_context to ensure we set back to global option value
|
# after running the test
|
with pd.option_context("mode.copy_on_write", False):
|
df = DataFrame({"a": [1, 2, 3], "b": [0.1, 0.2, 0.3]})
|
subset = df[:]
|
subset.iloc[0, 0] = 0
|
# df updated with CoW disabled
|
assert df.iloc[0, 0] == 0
|
|
pd.options.mode.copy_on_write = True
|
df = DataFrame({"a": [1, 2, 3], "b": [0.1, 0.2, 0.3]})
|
subset = df[:]
|
subset.iloc[0, 0] = 0
|
# df not updated with CoW enabled
|
assert df.iloc[0, 0] == 1
|
|
pd.options.mode.copy_on_write = False
|
df = DataFrame({"a": [1, 2, 3], "b": [0.1, 0.2, 0.3]})
|
subset = df[:]
|
subset.iloc[0, 0] = 0
|
# df updated with CoW disabled
|
assert df.iloc[0, 0] == 0
|
|
|
@td.skip_array_manager_invalid_test
|
@pytest.mark.parametrize("dtype", [np.intp, np.int8])
|
@pytest.mark.parametrize(
|
"locs, arr",
|
[
|
([0], np.array([-1, -2, -3])),
|
([1], np.array([-1, -2, -3])),
|
([5], np.array([-1, -2, -3])),
|
([0, 1], np.array([[-1, -2, -3], [-4, -5, -6]]).T),
|
([0, 2], np.array([[-1, -2, -3], [-4, -5, -6]]).T),
|
([0, 1, 2], np.array([[-1, -2, -3], [-4, -5, -6], [-4, -5, -6]]).T),
|
([1, 2], np.array([[-1, -2, -3], [-4, -5, -6]]).T),
|
([1, 3], np.array([[-1, -2, -3], [-4, -5, -6]]).T),
|
([1, 3], np.array([[-1, -2, -3], [-4, -5, -6]]).T),
|
],
|
)
|
def test_iset_splits_blocks_inplace(using_copy_on_write, locs, arr, dtype):
|
# Nothing currently calls iset with
|
# more than 1 loc with inplace=True (only happens with inplace=False)
|
# but ensure that it works
|
df = DataFrame(
|
{
|
"a": [1, 2, 3],
|
"b": [4, 5, 6],
|
"c": [7, 8, 9],
|
"d": [10, 11, 12],
|
"e": [13, 14, 15],
|
"f": Series(["a", "b", "c"], dtype=object),
|
},
|
)
|
arr = arr.astype(dtype)
|
df_orig = df.copy()
|
df2 = df.copy(deep=None) # Trigger a CoW (if enabled, otherwise makes copy)
|
df2._mgr.iset(locs, arr, inplace=True)
|
|
tm.assert_frame_equal(df, df_orig)
|
|
if using_copy_on_write:
|
for i, col in enumerate(df.columns):
|
if i not in locs:
|
assert np.shares_memory(get_array(df, col), get_array(df2, col))
|
else:
|
for col in df.columns:
|
assert not np.shares_memory(get_array(df, col), get_array(df2, col))
|
|
|
def test_exponential_backoff():
|
# GH#55518
|
df = DataFrame({"a": [1, 2, 3]})
|
for i in range(490):
|
df.copy(deep=False)
|
|
assert len(df._mgr.blocks[0].refs.referenced_blocks) == 491
|
|
df = DataFrame({"a": [1, 2, 3]})
|
dfs = [df.copy(deep=False) for i in range(510)]
|
|
for i in range(20):
|
df.copy(deep=False)
|
assert len(df._mgr.blocks[0].refs.referenced_blocks) == 531
|
assert df._mgr.blocks[0].refs.clear_counter == 1000
|
|
for i in range(500):
|
df.copy(deep=False)
|
|
# Don't reduce since we still have over 500 objects alive
|
assert df._mgr.blocks[0].refs.clear_counter == 1000
|
|
dfs = dfs[:300]
|
for i in range(500):
|
df.copy(deep=False)
|
|
# Reduce since there are less than 500 objects alive
|
assert df._mgr.blocks[0].refs.clear_counter == 500
|
