Updated script that can be controled by Nodejs web app

lib/python3.13/site-packages/pandas/tests/copy_view/test_internals.py

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+import numpy as np
+import pytest
+
+import pandas.util._test_decorators as td
+
+import pandas as pd
+from pandas import DataFrame
+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": ["a", "b", "c"],
+        },
+    )
+    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