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ckpts/llama-3b/global_step100/bf16_zero_pp_rank_125_mp_rank_01_optim_states.pt

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ckpts/llama-3b/global_step100/bf16_zero_pp_rank_200_mp_rank_03_optim_states.pt

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ckpts/llama-3b/global_step100/bf16_zero_pp_rank_34_mp_rank_00_optim_states.pt

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ckpts/llama-3b/global_step100/bf16_zero_pp_rank_3_mp_rank_01_optim_states.pt

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ckpts/llama-3b/global_step100/layer_14-model_01-model_states.pt

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ckpts/llama-3b/global_step100/layer_21-model_01-model_states.pt

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venv/lib/python3.10/site-packages/pandas/core/arrays/arrow/__init__.py

@@ -0,0 +1,7 @@
+from pandas.core.arrays.arrow.accessors import (
+    ListAccessor,
+    StructAccessor,
+)
+from pandas.core.arrays.arrow.array import ArrowExtensionArray
+
+__all__ = ["ArrowExtensionArray", "StructAccessor", "ListAccessor"]

venv/lib/python3.10/site-packages/pandas/core/arrays/arrow/_arrow_utils.py

@@ -0,0 +1,66 @@
+from __future__ import annotations
+
+import warnings
+
+import numpy as np
+import pyarrow
+
+from pandas.errors import PerformanceWarning
+from pandas.util._exceptions import find_stack_level
+
+
+def fallback_performancewarning(version: str | None = None) -> None:
+    """
+    Raise a PerformanceWarning for falling back to ExtensionArray's
+    non-pyarrow method
+    """
+    msg = "Falling back on a non-pyarrow code path which may decrease performance."
+    if version is not None:
+        msg += f" Upgrade to pyarrow >={version} to possibly suppress this warning."
+    warnings.warn(msg, PerformanceWarning, stacklevel=find_stack_level())
+
+
+def pyarrow_array_to_numpy_and_mask(
+    arr, dtype: np.dtype
+) -> tuple[np.ndarray, np.ndarray]:
+    """
+    Convert a primitive pyarrow.Array to a numpy array and boolean mask based
+    on the buffers of the Array.
+
+    At the moment pyarrow.BooleanArray is not supported.
+
+    Parameters
+    ----------
+    arr : pyarrow.Array
+    dtype : numpy.dtype
+
+    Returns
+    -------
+    (data, mask)
+        Tuple of two numpy arrays with the raw data (with specified dtype) and
+        a boolean mask (validity mask, so False means missing)
+    """
+    dtype = np.dtype(dtype)
+
+    if pyarrow.types.is_null(arr.type):
+        # No initialization of data is needed since everything is null
+        data = np.empty(len(arr), dtype=dtype)
+        mask = np.zeros(len(arr), dtype=bool)
+        return data, mask
+    buflist = arr.buffers()
+    # Since Arrow buffers might contain padding and the data might be offset,
+    # the buffer gets sliced here before handing it to numpy.
+    # See also https://github.com/pandas-dev/pandas/issues/40896
+    offset = arr.offset * dtype.itemsize
+    length = len(arr) * dtype.itemsize
+    data_buf = buflist[1][offset : offset + length]
+    data = np.frombuffer(data_buf, dtype=dtype)
+    bitmask = buflist[0]
+    if bitmask is not None:
+        mask = pyarrow.BooleanArray.from_buffers(
+            pyarrow.bool_(), len(arr), [None, bitmask], offset=arr.offset
+        )
+        mask = np.asarray(mask)
+    else:
+        mask = np.ones(len(arr), dtype=bool)
+    return data, mask

venv/lib/python3.10/site-packages/pandas/core/arrays/arrow/accessors.py

@@ -0,0 +1,473 @@
+"""Accessors for arrow-backed data."""
+
+from __future__ import annotations
+
+from abc import (
+    ABCMeta,
+    abstractmethod,
+)
+from typing import (
+    TYPE_CHECKING,
+    cast,
+)
+
+from pandas.compat import (
+    pa_version_under10p1,
+    pa_version_under11p0,
+)
+
+from pandas.core.dtypes.common import is_list_like
+
+if not pa_version_under10p1:
+    import pyarrow as pa
+    import pyarrow.compute as pc
+
+    from pandas.core.dtypes.dtypes import ArrowDtype
+
+if TYPE_CHECKING:
+    from collections.abc import Iterator
+
+    from pandas import (
+        DataFrame,
+        Series,
+    )
+
+
+class ArrowAccessor(metaclass=ABCMeta):
+    @abstractmethod
+    def __init__(self, data, validation_msg: str) -> None:
+        self._data = data
+        self._validation_msg = validation_msg
+        self._validate(data)
+
+    @abstractmethod
+    def _is_valid_pyarrow_dtype(self, pyarrow_dtype) -> bool:
+        pass
+
+    def _validate(self, data):
+        dtype = data.dtype
+        if not isinstance(dtype, ArrowDtype):
+            # Raise AttributeError so that inspect can handle non-struct Series.
+            raise AttributeError(self._validation_msg.format(dtype=dtype))
+
+        if not self._is_valid_pyarrow_dtype(dtype.pyarrow_dtype):
+            # Raise AttributeError so that inspect can handle invalid Series.
+            raise AttributeError(self._validation_msg.format(dtype=dtype))
+
+    @property
+    def _pa_array(self):
+        return self._data.array._pa_array
+
+
+class ListAccessor(ArrowAccessor):
+    """
+    Accessor object for list data properties of the Series values.
+
+    Parameters
+    ----------
+    data : Series
+        Series containing Arrow list data.
+    """
+
+    def __init__(self, data=None) -> None:
+        super().__init__(
+            data,
+            validation_msg="Can only use the '.list' accessor with "
+            "'list[pyarrow]' dtype, not {dtype}.",
+        )
+
+    def _is_valid_pyarrow_dtype(self, pyarrow_dtype) -> bool:
+        return (
+            pa.types.is_list(pyarrow_dtype)
+            or pa.types.is_fixed_size_list(pyarrow_dtype)
+            or pa.types.is_large_list(pyarrow_dtype)
+        )
+
+    def len(self) -> Series:
+        """
+        Return the length of each list in the Series.
+
+        Returns
+        -------
+        pandas.Series
+            The length of each list.
+
+        Examples
+        --------
+        >>> import pyarrow as pa
+        >>> s = pd.Series(
+        ...     [
+        ...         [1, 2, 3],
+        ...         [3],
+        ...     ],
+        ...     dtype=pd.ArrowDtype(pa.list_(
+        ...         pa.int64()
+        ...     ))
+        ... )
+        >>> s.list.len()
+        0    3
+        1    1
+        dtype: int32[pyarrow]
+        """
+        from pandas import Series
+
+        value_lengths = pc.list_value_length(self._pa_array)
+        return Series(value_lengths, dtype=ArrowDtype(value_lengths.type))
+
+    def __getitem__(self, key: int | slice) -> Series:
+        """
+        Index or slice lists in the Series.
+
+        Parameters
+        ----------
+        key : int | slice
+            Index or slice of indices to access from each list.
+
+        Returns
+        -------
+        pandas.Series
+            The list at requested index.
+
+        Examples
+        --------
+        >>> import pyarrow as pa
+        >>> s = pd.Series(
+        ...     [
+        ...         [1, 2, 3],
+        ...         [3],
+        ...     ],
+        ...     dtype=pd.ArrowDtype(pa.list_(
+        ...         pa.int64()
+        ...     ))
+        ... )
+        >>> s.list[0]
+        0    1
+        1    3
+        dtype: int64[pyarrow]
+        """
+        from pandas import Series
+
+        if isinstance(key, int):
+            # TODO: Support negative key but pyarrow does not allow
+            # element index to be an array.
+            # if key < 0:
+            #     key = pc.add(key, pc.list_value_length(self._pa_array))
+            element = pc.list_element(self._pa_array, key)
+            return Series(element, dtype=ArrowDtype(element.type))
+        elif isinstance(key, slice):
+            if pa_version_under11p0:
+                raise NotImplementedError(
+                    f"List slice not supported by pyarrow {pa.__version__}."
+                )
+
+            # TODO: Support negative start/stop/step, ideally this would be added
+            # upstream in pyarrow.
+            start, stop, step = key.start, key.stop, key.step
+            if start is None:
+                # TODO: When adding negative step support
+                #  this should be setto last element of array
+                # when step is negative.
+                start = 0
+            if step is None:
+                step = 1
+            sliced = pc.list_slice(self._pa_array, start, stop, step)
+            return Series(sliced, dtype=ArrowDtype(sliced.type))
+        else:
+            raise ValueError(f"key must be an int or slice, got {type(key).__name__}")
+
+    def __iter__(self) -> Iterator:
+        raise TypeError(f"'{type(self).__name__}' object is not iterable")
+
+    def flatten(self) -> Series:
+        """
+        Flatten list values.
+
+        Returns
+        -------
+        pandas.Series
+            The data from all lists in the series flattened.
+
+        Examples
+        --------
+        >>> import pyarrow as pa
+        >>> s = pd.Series(
+        ...     [
+        ...         [1, 2, 3],
+        ...         [3],
+        ...     ],
+        ...     dtype=pd.ArrowDtype(pa.list_(
+        ...         pa.int64()
+        ...     ))
+        ... )
+        >>> s.list.flatten()
+        0    1
+        1    2
+        2    3
+        3    3
+        dtype: int64[pyarrow]
+        """
+        from pandas import Series
+
+        flattened = pc.list_flatten(self._pa_array)
+        return Series(flattened, dtype=ArrowDtype(flattened.type))
+
+
+class StructAccessor(ArrowAccessor):
+    """
+    Accessor object for structured data properties of the Series values.
+
+    Parameters
+    ----------
+    data : Series
+        Series containing Arrow struct data.
+    """
+
+    def __init__(self, data=None) -> None:
+        super().__init__(
+            data,
+            validation_msg=(
+                "Can only use the '.struct' accessor with 'struct[pyarrow]' "
+                "dtype, not {dtype}."
+            ),
+        )
+
+    def _is_valid_pyarrow_dtype(self, pyarrow_dtype) -> bool:
+        return pa.types.is_struct(pyarrow_dtype)
+
+    @property
+    def dtypes(self) -> Series:
+        """
+        Return the dtype object of each child field of the struct.
+
+        Returns
+        -------
+        pandas.Series
+            The data type of each child field.
+
+        Examples
+        --------
+        >>> import pyarrow as pa
+        >>> s = pd.Series(
+        ...     [
+        ...         {"version": 1, "project": "pandas"},
+        ...         {"version": 2, "project": "pandas"},
+        ...         {"version": 1, "project": "numpy"},
+        ...     ],
+        ...     dtype=pd.ArrowDtype(pa.struct(
+        ...         [("version", pa.int64()), ("project", pa.string())]
+        ...     ))
+        ... )
+        >>> s.struct.dtypes
+        version     int64[pyarrow]
+        project    string[pyarrow]
+        dtype: object
+        """
+        from pandas import (
+            Index,
+            Series,
+        )
+
+        pa_type = self._data.dtype.pyarrow_dtype
+        types = [ArrowDtype(struct.type) for struct in pa_type]
+        names = [struct.name for struct in pa_type]
+        return Series(types, index=Index(names))
+
+    def field(
+        self,
+        name_or_index: list[str]
+        | list[bytes]
+        | list[int]
+        | pc.Expression
+        | bytes
+        | str
+        | int,
+    ) -> Series:
+        """
+        Extract a child field of a struct as a Series.
+
+        Parameters
+        ----------
+        name_or_index : str | bytes | int | expression | list
+            Name or index of the child field to extract.
+
+            For list-like inputs, this will index into a nested
+            struct.
+
+        Returns
+        -------
+        pandas.Series
+            The data corresponding to the selected child field.
+
+        See Also
+        --------
+        Series.struct.explode : Return all child fields as a DataFrame.
+
+        Notes
+        -----
+        The name of the resulting Series will be set using the following
+        rules:
+
+        - For string, bytes, or integer `name_or_index` (or a list of these, for
+          a nested selection), the Series name is set to the selected
+          field's name.
+        - For a :class:`pyarrow.compute.Expression`, this is set to
+          the string form of the expression.
+        - For list-like `name_or_index`, the name will be set to the
+          name of the final field selected.
+
+        Examples
+        --------
+        >>> import pyarrow as pa
+        >>> s = pd.Series(
+        ...     [
+        ...         {"version": 1, "project": "pandas"},
+        ...         {"version": 2, "project": "pandas"},
+        ...         {"version": 1, "project": "numpy"},
+        ...     ],
+        ...     dtype=pd.ArrowDtype(pa.struct(
+        ...         [("version", pa.int64()), ("project", pa.string())]
+        ...     ))
+        ... )
+
+        Extract by field name.
+
+        >>> s.struct.field("project")
+        0    pandas
+        1    pandas
+        2     numpy
+        Name: project, dtype: string[pyarrow]
+
+        Extract by field index.
+
+        >>> s.struct.field(0)
+        0    1
+        1    2
+        2    1
+        Name: version, dtype: int64[pyarrow]
+
+        Or an expression
+
+        >>> import pyarrow.compute as pc
+        >>> s.struct.field(pc.field("project"))
+        0    pandas
+        1    pandas
+        2     numpy
+        Name: project, dtype: string[pyarrow]
+
+        For nested struct types, you can pass a list of values to index
+        multiple levels:
+
+        >>> version_type = pa.struct([
+        ...     ("major", pa.int64()),
+        ...     ("minor", pa.int64()),
+        ... ])
+        >>> s = pd.Series(
+        ...     [
+        ...         {"version": {"major": 1, "minor": 5}, "project": "pandas"},
+        ...         {"version": {"major": 2, "minor": 1}, "project": "pandas"},
+        ...         {"version": {"major": 1, "minor": 26}, "project": "numpy"},
+        ...     ],
+        ...     dtype=pd.ArrowDtype(pa.struct(
+        ...         [("version", version_type), ("project", pa.string())]
+        ...     ))
+        ... )
+        >>> s.struct.field(["version", "minor"])
+        0     5
+        1     1
+        2    26
+        Name: minor, dtype: int64[pyarrow]
+        >>> s.struct.field([0, 0])
+        0    1
+        1    2
+        2    1
+        Name: major, dtype: int64[pyarrow]
+        """
+        from pandas import Series
+
+        def get_name(
+            level_name_or_index: list[str]
+            | list[bytes]
+            | list[int]
+            | pc.Expression
+            | bytes
+            | str
+            | int,
+            data: pa.ChunkedArray,
+        ):
+            if isinstance(level_name_or_index, int):
+                name = data.type.field(level_name_or_index).name
+            elif isinstance(level_name_or_index, (str, bytes)):
+                name = level_name_or_index
+            elif isinstance(level_name_or_index, pc.Expression):
+                name = str(level_name_or_index)
+            elif is_list_like(level_name_or_index):
+                # For nested input like [2, 1, 2]
+                # iteratively get the struct and field name. The last
+                # one is used for the name of the index.
+                level_name_or_index = list(reversed(level_name_or_index))
+                selected = data
+                while level_name_or_index:
+                    # we need the cast, otherwise mypy complains about
+                    # getting ints, bytes, or str here, which isn't possible.
+                    level_name_or_index = cast(list, level_name_or_index)
+                    name_or_index = level_name_or_index.pop()
+                    name = get_name(name_or_index, selected)
+                    selected = selected.type.field(selected.type.get_field_index(name))
+                    name = selected.name
+            else:
+                raise ValueError(
+                    "name_or_index must be an int, str, bytes, "
+                    "pyarrow.compute.Expression, or list of those"
+                )
+            return name
+
+        pa_arr = self._data.array._pa_array
+        name = get_name(name_or_index, pa_arr)
+        field_arr = pc.struct_field(pa_arr, name_or_index)
+
+        return Series(
+            field_arr,
+            dtype=ArrowDtype(field_arr.type),
+            index=self._data.index,
+            name=name,
+        )
+
+    def explode(self) -> DataFrame:
+        """
+        Extract all child fields of a struct as a DataFrame.
+
+        Returns
+        -------
+        pandas.DataFrame
+            The data corresponding to all child fields.
+
+        See Also
+        --------
+        Series.struct.field : Return a single child field as a Series.
+
+        Examples
+        --------
+        >>> import pyarrow as pa
+        >>> s = pd.Series(
+        ...     [
+        ...         {"version": 1, "project": "pandas"},
+        ...         {"version": 2, "project": "pandas"},
+        ...         {"version": 1, "project": "numpy"},
+        ...     ],
+        ...     dtype=pd.ArrowDtype(pa.struct(
+        ...         [("version", pa.int64()), ("project", pa.string())]
+        ...     ))
+        ... )
+
+        >>> s.struct.explode()
+           version project
+        0        1  pandas
+        1        2  pandas
+        2        1   numpy
+        """
+        from pandas import concat
+
+        pa_type = self._pa_array.type
+        return concat(
+            [self.field(i) for i in range(pa_type.num_fields)], axis="columns"
+        )

venv/lib/python3.10/site-packages/pandas/core/arrays/arrow/extension_types.py

@@ -0,0 +1,174 @@
+from __future__ import annotations
+
+import json
+from typing import TYPE_CHECKING
+
+import pyarrow
+
+from pandas.compat import pa_version_under14p1
+
+from pandas.core.dtypes.dtypes import (
+    IntervalDtype,
+    PeriodDtype,
+)
+
+from pandas.core.arrays.interval import VALID_CLOSED
+
+if TYPE_CHECKING:
+    from pandas._typing import IntervalClosedType
+
+
+class ArrowPeriodType(pyarrow.ExtensionType):
+    def __init__(self, freq) -> None:
+        # attributes need to be set first before calling
+        # super init (as that calls serialize)
+        self._freq = freq
+        pyarrow.ExtensionType.__init__(self, pyarrow.int64(), "pandas.period")
+
+    @property
+    def freq(self):
+        return self._freq
+
+    def __arrow_ext_serialize__(self) -> bytes:
+        metadata = {"freq": self.freq}
+        return json.dumps(metadata).encode()
+
+    @classmethod
+    def __arrow_ext_deserialize__(cls, storage_type, serialized) -> ArrowPeriodType:
+        metadata = json.loads(serialized.decode())
+        return ArrowPeriodType(metadata["freq"])
+
+    def __eq__(self, other):
+        if isinstance(other, pyarrow.BaseExtensionType):
+            return type(self) == type(other) and self.freq == other.freq
+        else:
+            return NotImplemented
+
+    def __ne__(self, other) -> bool:
+        return not self == other
+
+    def __hash__(self) -> int:
+        return hash((str(self), self.freq))
+
+    def to_pandas_dtype(self) -> PeriodDtype:
+        return PeriodDtype(freq=self.freq)
+
+
+# register the type with a dummy instance
+_period_type = ArrowPeriodType("D")
+pyarrow.register_extension_type(_period_type)
+
+
+class ArrowIntervalType(pyarrow.ExtensionType):
+    def __init__(self, subtype, closed: IntervalClosedType) -> None:
+        # attributes need to be set first before calling
+        # super init (as that calls serialize)
+        assert closed in VALID_CLOSED
+        self._closed: IntervalClosedType = closed
+        if not isinstance(subtype, pyarrow.DataType):
+            subtype = pyarrow.type_for_alias(str(subtype))
+        self._subtype = subtype
+
+        storage_type = pyarrow.struct([("left", subtype), ("right", subtype)])
+        pyarrow.ExtensionType.__init__(self, storage_type, "pandas.interval")
+
+    @property
+    def subtype(self):
+        return self._subtype
+
+    @property
+    def closed(self) -> IntervalClosedType:
+        return self._closed
+
+    def __arrow_ext_serialize__(self) -> bytes:
+        metadata = {"subtype": str(self.subtype), "closed": self.closed}
+        return json.dumps(metadata).encode()
+
+    @classmethod
+    def __arrow_ext_deserialize__(cls, storage_type, serialized) -> ArrowIntervalType:
+        metadata = json.loads(serialized.decode())
+        subtype = pyarrow.type_for_alias(metadata["subtype"])
+        closed = metadata["closed"]
+        return ArrowIntervalType(subtype, closed)
+
+    def __eq__(self, other):
+        if isinstance(other, pyarrow.BaseExtensionType):
+            return (
+                type(self) == type(other)
+                and self.subtype == other.subtype
+                and self.closed == other.closed
+            )
+        else:
+            return NotImplemented
+
+    def __ne__(self, other) -> bool:
+        return not self == other
+
+    def __hash__(self) -> int:
+        return hash((str(self), str(self.subtype), self.closed))
+
+    def to_pandas_dtype(self) -> IntervalDtype:
+        return IntervalDtype(self.subtype.to_pandas_dtype(), self.closed)
+
+
+# register the type with a dummy instance
+_interval_type = ArrowIntervalType(pyarrow.int64(), "left")
+pyarrow.register_extension_type(_interval_type)
+
+
+_ERROR_MSG = """\
+Disallowed deserialization of 'arrow.py_extension_type':
+storage_type = {storage_type}
+serialized = {serialized}
+pickle disassembly:\n{pickle_disassembly}
+
+Reading of untrusted Parquet or Feather files with a PyExtensionType column
+allows arbitrary code execution.
+If you trust this file, you can enable reading the extension type by one of:
+
+- upgrading to pyarrow >= 14.0.1, and call `pa.PyExtensionType.set_auto_load(True)`
+- install pyarrow-hotfix (`pip install pyarrow-hotfix`) and disable it by running
+  `import pyarrow_hotfix; pyarrow_hotfix.uninstall()`
+
+We strongly recommend updating your Parquet/Feather files to use extension types
+derived from `pyarrow.ExtensionType` instead, and register this type explicitly.
+"""
+
+
+def patch_pyarrow():
+    # starting from pyarrow 14.0.1, it has its own mechanism
+    if not pa_version_under14p1:
+        return
+
+    # if https://github.com/pitrou/pyarrow-hotfix was installed and enabled
+    if getattr(pyarrow, "_hotfix_installed", False):
+        return
+
+    class ForbiddenExtensionType(pyarrow.ExtensionType):
+        def __arrow_ext_serialize__(self):
+            return b""
+
+        @classmethod
+        def __arrow_ext_deserialize__(cls, storage_type, serialized):
+            import io
+            import pickletools
+
+            out = io.StringIO()
+            pickletools.dis(serialized, out)
+            raise RuntimeError(
+                _ERROR_MSG.format(
+                    storage_type=storage_type,
+                    serialized=serialized,
+                    pickle_disassembly=out.getvalue(),
+                )
+            )
+
+    pyarrow.unregister_extension_type("arrow.py_extension_type")
+    pyarrow.register_extension_type(
+        ForbiddenExtensionType(pyarrow.null(), "arrow.py_extension_type")
+    )
+
+    pyarrow._hotfix_installed = True
+
+
+patch_pyarrow()

venv/lib/python3.10/site-packages/pandas/core/arrays/boolean.py

@@ -0,0 +1,407 @@
+from __future__ import annotations
+
+import numbers
+from typing import (
+    TYPE_CHECKING,
+    ClassVar,
+    cast,
+)
+
+import numpy as np
+
+from pandas._libs import (
+    lib,
+    missing as libmissing,
+)
+
+from pandas.core.dtypes.common import is_list_like
+from pandas.core.dtypes.dtypes import register_extension_dtype
+from pandas.core.dtypes.missing import isna
+
+from pandas.core import ops
+from pandas.core.array_algos import masked_accumulations
+from pandas.core.arrays.masked import (
+    BaseMaskedArray,
+    BaseMaskedDtype,
+)
+
+if TYPE_CHECKING:
+    import pyarrow
+
+    from pandas._typing import (
+        Dtype,
+        DtypeObj,
+        Self,
+        npt,
+        type_t,
+    )
+
+
+@register_extension_dtype
+class BooleanDtype(BaseMaskedDtype):
+    """
+    Extension dtype for boolean data.
+
+    .. warning::
+
+       BooleanDtype is considered experimental. The implementation and
+       parts of the API may change without warning.
+
+    Attributes
+    ----------
+    None
+
+    Methods
+    -------
+    None
+
+    Examples
+    --------
+    >>> pd.BooleanDtype()
+    BooleanDtype
+    """
+
+    name: ClassVar[str] = "boolean"
+
+    # https://github.com/python/mypy/issues/4125
+    # error: Signature of "type" incompatible with supertype "BaseMaskedDtype"
+    @property
+    def type(self) -> type:  # type: ignore[override]
+        return np.bool_
+
+    @property
+    def kind(self) -> str:
+        return "b"
+
+    @property
+    def numpy_dtype(self) -> np.dtype:
+        return np.dtype("bool")
+
+    @classmethod
+    def construct_array_type(cls) -> type_t[BooleanArray]:
+        """
+        Return the array type associated with this dtype.
+
+        Returns
+        -------
+        type
+        """
+        return BooleanArray
+
+    def __repr__(self) -> str:
+        return "BooleanDtype"
+
+    @property
+    def _is_boolean(self) -> bool:
+        return True
+
+    @property
+    def _is_numeric(self) -> bool:
+        return True
+
+    def __from_arrow__(
+        self, array: pyarrow.Array | pyarrow.ChunkedArray
+    ) -> BooleanArray:
+        """
+        Construct BooleanArray from pyarrow Array/ChunkedArray.
+        """
+        import pyarrow
+
+        if array.type != pyarrow.bool_() and not pyarrow.types.is_null(array.type):
+            raise TypeError(f"Expected array of boolean type, got {array.type} instead")
+
+        if isinstance(array, pyarrow.Array):
+            chunks = [array]
+            length = len(array)
+        else:
+            # pyarrow.ChunkedArray
+            chunks = array.chunks
+            length = array.length()
+
+        if pyarrow.types.is_null(array.type):
+            mask = np.ones(length, dtype=bool)
+            # No need to init data, since all null
+            data = np.empty(length, dtype=bool)
+            return BooleanArray(data, mask)
+
+        results = []
+        for arr in chunks:
+            buflist = arr.buffers()
+            data = pyarrow.BooleanArray.from_buffers(
+                arr.type, len(arr), [None, buflist[1]], offset=arr.offset
+            ).to_numpy(zero_copy_only=False)
+            if arr.null_count != 0:
+                mask = pyarrow.BooleanArray.from_buffers(
+                    arr.type, len(arr), [None, buflist[0]], offset=arr.offset
+                ).to_numpy(zero_copy_only=False)
+                mask = ~mask
+            else:
+                mask = np.zeros(len(arr), dtype=bool)
+
+            bool_arr = BooleanArray(data, mask)
+            results.append(bool_arr)
+
+        if not results:
+            return BooleanArray(
+                np.array([], dtype=np.bool_), np.array([], dtype=np.bool_)
+            )
+        else:
+            return BooleanArray._concat_same_type(results)
+
+
+def coerce_to_array(
+    values, mask=None, copy: bool = False
+) -> tuple[np.ndarray, np.ndarray]:
+    """
+    Coerce the input values array to numpy arrays with a mask.
+
+    Parameters
+    ----------
+    values : 1D list-like
+    mask : bool 1D array, optional
+    copy : bool, default False
+        if True, copy the input
+
+    Returns
+    -------
+    tuple of (values, mask)
+    """
+    if isinstance(values, BooleanArray):
+        if mask is not None:
+            raise ValueError("cannot pass mask for BooleanArray input")
+        values, mask = values._data, values._mask
+        if copy:
+            values = values.copy()
+            mask = mask.copy()
+        return values, mask
+
+    mask_values = None
+    if isinstance(values, np.ndarray) and values.dtype == np.bool_:
+        if copy:
+            values = values.copy()
+    elif isinstance(values, np.ndarray) and values.dtype.kind in "iufcb":
+        mask_values = isna(values)
+
+        values_bool = np.zeros(len(values), dtype=bool)
+        values_bool[~mask_values] = values[~mask_values].astype(bool)
+
+        if not np.all(
+            values_bool[~mask_values].astype(values.dtype) == values[~mask_values]
+        ):
+            raise TypeError("Need to pass bool-like values")
+
+        values = values_bool
+    else:
+        values_object = np.asarray(values, dtype=object)
+
+        inferred_dtype = lib.infer_dtype(values_object, skipna=True)
+        integer_like = ("floating", "integer", "mixed-integer-float")
+        if inferred_dtype not in ("boolean", "empty") + integer_like:
+            raise TypeError("Need to pass bool-like values")
+
+        # mypy does not narrow the type of mask_values to npt.NDArray[np.bool_]
+        # within this branch, it assumes it can also be None
+        mask_values = cast("npt.NDArray[np.bool_]", isna(values_object))
+        values = np.zeros(len(values), dtype=bool)
+        values[~mask_values] = values_object[~mask_values].astype(bool)
+
+        # if the values were integer-like, validate it were actually 0/1's
+        if (inferred_dtype in integer_like) and not (
+            np.all(
+                values[~mask_values].astype(float)
+                == values_object[~mask_values].astype(float)
+            )
+        ):
+            raise TypeError("Need to pass bool-like values")
+
+    if mask is None and mask_values is None:
+        mask = np.zeros(values.shape, dtype=bool)
+    elif mask is None:
+        mask = mask_values
+    else:
+        if isinstance(mask, np.ndarray) and mask.dtype == np.bool_:
+            if mask_values is not None:
+                mask = mask | mask_values
+            else:
+                if copy:
+                    mask = mask.copy()
+        else:
+            mask = np.array(mask, dtype=bool)
+            if mask_values is not None:
+                mask = mask | mask_values
+
+    if values.shape != mask.shape:
+        raise ValueError("values.shape and mask.shape must match")
+
+    return values, mask
+
+
+class BooleanArray(BaseMaskedArray):
+    """
+    Array of boolean (True/False) data with missing values.
+
+    This is a pandas Extension array for boolean data, under the hood
+    represented by 2 numpy arrays: a boolean array with the data and
+    a boolean array with the mask (True indicating missing).
+
+    BooleanArray implements Kleene logic (sometimes called three-value
+    logic) for logical operations. See :ref:`boolean.kleene` for more.
+
+    To construct an BooleanArray from generic array-like input, use
+    :func:`pandas.array` specifying ``dtype="boolean"`` (see examples
+    below).
+
+    .. warning::
+
+       BooleanArray is considered experimental. The implementation and
+       parts of the API may change without warning.
+
+    Parameters
+    ----------
+    values : numpy.ndarray
+        A 1-d boolean-dtype array with the data.
+    mask : numpy.ndarray
+        A 1-d boolean-dtype array indicating missing values (True
+        indicates missing).
+    copy : bool, default False
+        Whether to copy the `values` and `mask` arrays.
+
+    Attributes
+    ----------
+    None
+
+    Methods
+    -------
+    None
+
+    Returns
+    -------
+    BooleanArray
+
+    Examples
+    --------
+    Create an BooleanArray with :func:`pandas.array`:
+
+    >>> pd.array([True, False, None], dtype="boolean")
+    <BooleanArray>
+    [True, False, <NA>]
+    Length: 3, dtype: boolean
+    """
+
+    # The value used to fill '_data' to avoid upcasting
+    _internal_fill_value = False
+    # Fill values used for any/all
+    # Incompatible types in assignment (expression has type "bool", base class
+    # "BaseMaskedArray" defined the type as "<typing special form>")
+    _truthy_value = True  # type: ignore[assignment]
+    _falsey_value = False  # type: ignore[assignment]
+    _TRUE_VALUES = {"True", "TRUE", "true", "1", "1.0"}
+    _FALSE_VALUES = {"False", "FALSE", "false", "0", "0.0"}
+
+    @classmethod
+    def _simple_new(cls, values: np.ndarray, mask: npt.NDArray[np.bool_]) -> Self:
+        result = super()._simple_new(values, mask)
+        result._dtype = BooleanDtype()
+        return result
+
+    def __init__(
+        self, values: np.ndarray, mask: np.ndarray, copy: bool = False
+    ) -> None:
+        if not (isinstance(values, np.ndarray) and values.dtype == np.bool_):
+            raise TypeError(
+                "values should be boolean numpy array. Use "
+                "the 'pd.array' function instead"
+            )
+        self._dtype = BooleanDtype()
+        super().__init__(values, mask, copy=copy)
+
+    @property
+    def dtype(self) -> BooleanDtype:
+        return self._dtype
+
+    @classmethod
+    def _from_sequence_of_strings(
+        cls,
+        strings: list[str],
+        *,
+        dtype: Dtype | None = None,
+        copy: bool = False,
+        true_values: list[str] | None = None,
+        false_values: list[str] | None = None,
+    ) -> BooleanArray:
+        true_values_union = cls._TRUE_VALUES.union(true_values or [])
+        false_values_union = cls._FALSE_VALUES.union(false_values or [])
+
+        def map_string(s) -> bool:
+            if s in true_values_union:
+                return True
+            elif s in false_values_union:
+                return False
+            else:
+                raise ValueError(f"{s} cannot be cast to bool")
+
+        scalars = np.array(strings, dtype=object)
+        mask = isna(scalars)
+        scalars[~mask] = list(map(map_string, scalars[~mask]))
+        return cls._from_sequence(scalars, dtype=dtype, copy=copy)
+
+    _HANDLED_TYPES = (np.ndarray, numbers.Number, bool, np.bool_)
+
+    @classmethod
+    def _coerce_to_array(
+        cls, value, *, dtype: DtypeObj, copy: bool = False
+    ) -> tuple[np.ndarray, np.ndarray]:
+        if dtype:
+            assert dtype == "boolean"
+        return coerce_to_array(value, copy=copy)
+
+    def _logical_method(self, other, op):
+        assert op.__name__ in {"or_", "ror_", "and_", "rand_", "xor", "rxor"}
+        other_is_scalar = lib.is_scalar(other)
+        mask = None
+
+        if isinstance(other, BooleanArray):
+            other, mask = other._data, other._mask
+        elif is_list_like(other):
+            other = np.asarray(other, dtype="bool")
+            if other.ndim > 1:
+                raise NotImplementedError("can only perform ops with 1-d structures")
+            other, mask = coerce_to_array(other, copy=False)
+        elif isinstance(other, np.bool_):
+            other = other.item()
+
+        if other_is_scalar and other is not libmissing.NA and not lib.is_bool(other):
+            raise TypeError(
+                "'other' should be pandas.NA or a bool. "
+                f"Got {type(other).__name__} instead."
+            )
+
+        if not other_is_scalar and len(self) != len(other):
+            raise ValueError("Lengths must match")
+
+        if op.__name__ in {"or_", "ror_"}:
+            result, mask = ops.kleene_or(self._data, other, self._mask, mask)
+        elif op.__name__ in {"and_", "rand_"}:
+            result, mask = ops.kleene_and(self._data, other, self._mask, mask)
+        else:
+            # i.e. xor, rxor
+            result, mask = ops.kleene_xor(self._data, other, self._mask, mask)
+
+        # i.e. BooleanArray
+        return self._maybe_mask_result(result, mask)
+
+    def _accumulate(
+        self, name: str, *, skipna: bool = True, **kwargs
+    ) -> BaseMaskedArray:
+        data = self._data
+        mask = self._mask
+        if name in ("cummin", "cummax"):
+            op = getattr(masked_accumulations, name)
+            data, mask = op(data, mask, skipna=skipna, **kwargs)
+            return self._simple_new(data, mask)
+        else:
+            from pandas.core.arrays import IntegerArray
+
+            return IntegerArray(data.astype(int), mask)._accumulate(
+                name, skipna=skipna, **kwargs
+            )

venv/lib/python3.10/site-packages/pandas/core/arrays/integer.py

@@ -0,0 +1,272 @@
+from __future__ import annotations
+
+from typing import ClassVar
+
+import numpy as np
+
+from pandas.core.dtypes.base import register_extension_dtype
+from pandas.core.dtypes.common import is_integer_dtype
+
+from pandas.core.arrays.numeric import (
+    NumericArray,
+    NumericDtype,
+)
+
+
+class IntegerDtype(NumericDtype):
+    """
+    An ExtensionDtype to hold a single size & kind of integer dtype.
+
+    These specific implementations are subclasses of the non-public
+    IntegerDtype. For example, we have Int8Dtype to represent signed int 8s.
+
+    The attributes name & type are set when these subclasses are created.
+    """
+
+    _default_np_dtype = np.dtype(np.int64)
+    _checker = is_integer_dtype
+
+    @classmethod
+    def construct_array_type(cls) -> type[IntegerArray]:
+        """
+        Return the array type associated with this dtype.
+
+        Returns
+        -------
+        type
+        """
+        return IntegerArray
+
+    @classmethod
+    def _get_dtype_mapping(cls) -> dict[np.dtype, IntegerDtype]:
+        return NUMPY_INT_TO_DTYPE
+
+    @classmethod
+    def _safe_cast(cls, values: np.ndarray, dtype: np.dtype, copy: bool) -> np.ndarray:
+        """
+        Safely cast the values to the given dtype.
+
+        "safe" in this context means the casting is lossless. e.g. if 'values'
+        has a floating dtype, each value must be an integer.
+        """
+        try:
+            return values.astype(dtype, casting="safe", copy=copy)
+        except TypeError as err:
+            casted = values.astype(dtype, copy=copy)
+            if (casted == values).all():
+                return casted
+
+            raise TypeError(
+                f"cannot safely cast non-equivalent {values.dtype} to {np.dtype(dtype)}"
+            ) from err
+
+
+class IntegerArray(NumericArray):
+    """
+    Array of integer (optional missing) values.
+
+    Uses :attr:`pandas.NA` as the missing value.
+
+    .. warning::
+
+       IntegerArray is currently experimental, and its API or internal
+       implementation may change without warning.
+
+    We represent an IntegerArray with 2 numpy arrays:
+
+    - data: contains a numpy integer array of the appropriate dtype
+    - mask: a boolean array holding a mask on the data, True is missing
+
+    To construct an IntegerArray from generic array-like input, use
+    :func:`pandas.array` with one of the integer dtypes (see examples).
+
+    See :ref:`integer_na` for more.
+
+    Parameters
+    ----------
+    values : numpy.ndarray
+        A 1-d integer-dtype array.
+    mask : numpy.ndarray
+        A 1-d boolean-dtype array indicating missing values.
+    copy : bool, default False
+        Whether to copy the `values` and `mask`.
+
+    Attributes
+    ----------
+    None
+
+    Methods
+    -------
+    None
+
+    Returns
+    -------
+    IntegerArray
+
+    Examples
+    --------
+    Create an IntegerArray with :func:`pandas.array`.
+
+    >>> int_array = pd.array([1, None, 3], dtype=pd.Int32Dtype())
+    >>> int_array
+    <IntegerArray>
+    [1, <NA>, 3]
+    Length: 3, dtype: Int32
+
+    String aliases for the dtypes are also available. They are capitalized.
+
+    >>> pd.array([1, None, 3], dtype='Int32')
+    <IntegerArray>
+    [1, <NA>, 3]
+    Length: 3, dtype: Int32
+
+    >>> pd.array([1, None, 3], dtype='UInt16')
+    <IntegerArray>
+    [1, <NA>, 3]
+    Length: 3, dtype: UInt16
+    """
+
+    _dtype_cls = IntegerDtype
+
+    # The value used to fill '_data' to avoid upcasting
+    _internal_fill_value = 1
+    # Fill values used for any/all
+    # Incompatible types in assignment (expression has type "int", base class
+    # "BaseMaskedArray" defined the type as "<typing special form>")
+    _truthy_value = 1  # type: ignore[assignment]
+    _falsey_value = 0  # type: ignore[assignment]
+
+
+_dtype_docstring = """
+An ExtensionDtype for {dtype} integer data.
+
+Uses :attr:`pandas.NA` as its missing value, rather than :attr:`numpy.nan`.
+
+Attributes
+----------
+None
+
+Methods
+-------
+None
+
+Examples
+--------
+For Int8Dtype:
+
+>>> ser = pd.Series([2, pd.NA], dtype=pd.Int8Dtype())
+>>> ser.dtype
+Int8Dtype()
+
+For Int16Dtype:
+
+>>> ser = pd.Series([2, pd.NA], dtype=pd.Int16Dtype())
+>>> ser.dtype
+Int16Dtype()
+
+For Int32Dtype:
+
+>>> ser = pd.Series([2, pd.NA], dtype=pd.Int32Dtype())
+>>> ser.dtype
+Int32Dtype()
+
+For Int64Dtype:
+
+>>> ser = pd.Series([2, pd.NA], dtype=pd.Int64Dtype())
+>>> ser.dtype
+Int64Dtype()
+
+For UInt8Dtype:
+
+>>> ser = pd.Series([2, pd.NA], dtype=pd.UInt8Dtype())
+>>> ser.dtype
+UInt8Dtype()
+
+For UInt16Dtype:
+
+>>> ser = pd.Series([2, pd.NA], dtype=pd.UInt16Dtype())
+>>> ser.dtype
+UInt16Dtype()
+
+For UInt32Dtype:
+
+>>> ser = pd.Series([2, pd.NA], dtype=pd.UInt32Dtype())
+>>> ser.dtype
+UInt32Dtype()
+
+For UInt64Dtype:
+
+>>> ser = pd.Series([2, pd.NA], dtype=pd.UInt64Dtype())
+>>> ser.dtype
+UInt64Dtype()
+"""
+
+# create the Dtype
+
+
+@register_extension_dtype
+class Int8Dtype(IntegerDtype):
+    type = np.int8
+    name: ClassVar[str] = "Int8"
+    __doc__ = _dtype_docstring.format(dtype="int8")
+
+
+@register_extension_dtype
+class Int16Dtype(IntegerDtype):
+    type = np.int16
+    name: ClassVar[str] = "Int16"
+    __doc__ = _dtype_docstring.format(dtype="int16")
+
+
+@register_extension_dtype
+class Int32Dtype(IntegerDtype):
+    type = np.int32
+    name: ClassVar[str] = "Int32"
+    __doc__ = _dtype_docstring.format(dtype="int32")
+
+
+@register_extension_dtype
+class Int64Dtype(IntegerDtype):
+    type = np.int64
+    name: ClassVar[str] = "Int64"
+    __doc__ = _dtype_docstring.format(dtype="int64")
+
+
+@register_extension_dtype
+class UInt8Dtype(IntegerDtype):
+    type = np.uint8
+    name: ClassVar[str] = "UInt8"
+    __doc__ = _dtype_docstring.format(dtype="uint8")
+
+
+@register_extension_dtype
+class UInt16Dtype(IntegerDtype):
+    type = np.uint16
+    name: ClassVar[str] = "UInt16"
+    __doc__ = _dtype_docstring.format(dtype="uint16")
+
+
+@register_extension_dtype
+class UInt32Dtype(IntegerDtype):
+    type = np.uint32
+    name: ClassVar[str] = "UInt32"
+    __doc__ = _dtype_docstring.format(dtype="uint32")
+
+
+@register_extension_dtype
+class UInt64Dtype(IntegerDtype):
+    type = np.uint64
+    name: ClassVar[str] = "UInt64"
+    __doc__ = _dtype_docstring.format(dtype="uint64")
+
+
+NUMPY_INT_TO_DTYPE: dict[np.dtype, IntegerDtype] = {
+    np.dtype(np.int8): Int8Dtype(),
+    np.dtype(np.int16): Int16Dtype(),
+    np.dtype(np.int32): Int32Dtype(),
+    np.dtype(np.int64): Int64Dtype(),
+    np.dtype(np.uint8): UInt8Dtype(),
+    np.dtype(np.uint16): UInt16Dtype(),
+    np.dtype(np.uint32): UInt32Dtype(),
+    np.dtype(np.uint64): UInt64Dtype(),
+}

venv/lib/python3.10/site-packages/pandas/core/arrays/masked.py

@@ -0,0 +1,1650 @@
+from __future__ import annotations
+
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    Callable,
+    Literal,
+    overload,
+)
+import warnings
+
+import numpy as np
+
+from pandas._libs import (
+    lib,
+    missing as libmissing,
+)
+from pandas._libs.tslibs import is_supported_dtype
+from pandas._typing import (
+    ArrayLike,
+    AstypeArg,
+    AxisInt,
+    DtypeObj,
+    FillnaOptions,
+    InterpolateOptions,
+    NpDtype,
+    PositionalIndexer,
+    Scalar,
+    ScalarIndexer,
+    Self,
+    SequenceIndexer,
+    Shape,
+    npt,
+)
+from pandas.compat import (
+    IS64,
+    is_platform_windows,
+)
+from pandas.errors import AbstractMethodError
+from pandas.util._decorators import doc
+from pandas.util._validators import validate_fillna_kwargs
+
+from pandas.core.dtypes.base import ExtensionDtype
+from pandas.core.dtypes.common import (
+    is_bool,
+    is_integer_dtype,
+    is_list_like,
+    is_scalar,
+    is_string_dtype,
+    pandas_dtype,
+)
+from pandas.core.dtypes.dtypes import BaseMaskedDtype
+from pandas.core.dtypes.missing import (
+    array_equivalent,
+    is_valid_na_for_dtype,
+    isna,
+    notna,
+)
+
+from pandas.core import (
+    algorithms as algos,
+    arraylike,
+    missing,
+    nanops,
+    ops,
+)
+from pandas.core.algorithms import (
+    factorize_array,
+    isin,
+    map_array,
+    mode,
+    take,
+)
+from pandas.core.array_algos import (
+    masked_accumulations,
+    masked_reductions,
+)
+from pandas.core.array_algos.quantile import quantile_with_mask
+from pandas.core.arraylike import OpsMixin
+from pandas.core.arrays._utils import to_numpy_dtype_inference
+from pandas.core.arrays.base import ExtensionArray
+from pandas.core.construction import (
+    array as pd_array,
+    ensure_wrapped_if_datetimelike,
+    extract_array,
+)
+from pandas.core.indexers import check_array_indexer
+from pandas.core.ops import invalid_comparison
+from pandas.core.util.hashing import hash_array
+
+if TYPE_CHECKING:
+    from collections.abc import (
+        Iterator,
+        Sequence,
+    )
+    from pandas import Series
+    from pandas.core.arrays import BooleanArray
+    from pandas._typing import (
+        NumpySorter,
+        NumpyValueArrayLike,
+    )
+    from pandas.core.arrays import FloatingArray
+
+from pandas.compat.numpy import function as nv
+
+
+class BaseMaskedArray(OpsMixin, ExtensionArray):
+    """
+    Base class for masked arrays (which use _data and _mask to store the data).
+
+    numpy based
+    """
+
+    # The value used to fill '_data' to avoid upcasting
+    _internal_fill_value: Scalar
+    # our underlying data and mask are each ndarrays
+    _data: np.ndarray
+    _mask: npt.NDArray[np.bool_]
+
+    # Fill values used for any/all
+    _truthy_value = Scalar  # bool(_truthy_value) = True
+    _falsey_value = Scalar  # bool(_falsey_value) = False
+
+    @classmethod
+    def _simple_new(cls, values: np.ndarray, mask: npt.NDArray[np.bool_]) -> Self:
+        result = BaseMaskedArray.__new__(cls)
+        result._data = values
+        result._mask = mask
+        return result
+
+    def __init__(
+        self, values: np.ndarray, mask: npt.NDArray[np.bool_], copy: bool = False
+    ) -> None:
+        # values is supposed to already be validated in the subclass
+        if not (isinstance(mask, np.ndarray) and mask.dtype == np.bool_):
+            raise TypeError(
+                "mask should be boolean numpy array. Use "
+                "the 'pd.array' function instead"
+            )
+        if values.shape != mask.shape:
+            raise ValueError("values.shape must match mask.shape")
+
+        if copy:
+            values = values.copy()
+            mask = mask.copy()
+
+        self._data = values
+        self._mask = mask
+
+    @classmethod
+    def _from_sequence(cls, scalars, *, dtype=None, copy: bool = False) -> Self:
+        values, mask = cls._coerce_to_array(scalars, dtype=dtype, copy=copy)
+        return cls(values, mask)
+
+    @classmethod
+    @doc(ExtensionArray._empty)
+    def _empty(cls, shape: Shape, dtype: ExtensionDtype):
+        values = np.empty(shape, dtype=dtype.type)
+        values.fill(cls._internal_fill_value)
+        mask = np.ones(shape, dtype=bool)
+        result = cls(values, mask)
+        if not isinstance(result, cls) or dtype != result.dtype:
+            raise NotImplementedError(
+                f"Default 'empty' implementation is invalid for dtype='{dtype}'"
+            )
+        return result
+
+    def _formatter(self, boxed: bool = False) -> Callable[[Any], str | None]:
+        # NEP 51: https://github.com/numpy/numpy/pull/22449
+        return str
+
+    @property
+    def dtype(self) -> BaseMaskedDtype:
+        raise AbstractMethodError(self)
+
+    @overload
+    def __getitem__(self, item: ScalarIndexer) -> Any:
+        ...
+
+    @overload
+    def __getitem__(self, item: SequenceIndexer) -> Self:
+        ...
+
+    def __getitem__(self, item: PositionalIndexer) -> Self | Any:
+        item = check_array_indexer(self, item)
+
+        newmask = self._mask[item]
+        if is_bool(newmask):
+            # This is a scalar indexing
+            if newmask:
+                return self.dtype.na_value
+            return self._data[item]
+
+        return self._simple_new(self._data[item], newmask)
+
+    def _pad_or_backfill(
+        self,
+        *,
+        method: FillnaOptions,
+        limit: int | None = None,
+        limit_area: Literal["inside", "outside"] | None = None,
+        copy: bool = True,
+    ) -> Self:
+        mask = self._mask
+
+        if mask.any():
+            func = missing.get_fill_func(method, ndim=self.ndim)
+
+            npvalues = self._data.T
+            new_mask = mask.T
+            if copy:
+                npvalues = npvalues.copy()
+                new_mask = new_mask.copy()
+            elif limit_area is not None:
+                mask = mask.copy()
+            func(npvalues, limit=limit, mask=new_mask)
+
+            if limit_area is not None and not mask.all():
+                mask = mask.T
+                neg_mask = ~mask
+                first = neg_mask.argmax()
+                last = len(neg_mask) - neg_mask[::-1].argmax() - 1
+                if limit_area == "inside":
+                    new_mask[:first] |= mask[:first]
+                    new_mask[last + 1 :] |= mask[last + 1 :]
+                elif limit_area == "outside":
+                    new_mask[first + 1 : last] |= mask[first + 1 : last]
+
+            if copy:
+                return self._simple_new(npvalues.T, new_mask.T)
+            else:
+                return self
+        else:
+            if copy:
+                new_values = self.copy()
+            else:
+                new_values = self
+        return new_values
+
+    @doc(ExtensionArray.fillna)
+    def fillna(
+        self, value=None, method=None, limit: int | None = None, copy: bool = True
+    ) -> Self:
+        value, method = validate_fillna_kwargs(value, method)
+
+        mask = self._mask
+
+        value = missing.check_value_size(value, mask, len(self))
+
+        if mask.any():
+            if method is not None:
+                func = missing.get_fill_func(method, ndim=self.ndim)
+                npvalues = self._data.T
+                new_mask = mask.T
+                if copy:
+                    npvalues = npvalues.copy()
+                    new_mask = new_mask.copy()
+                func(npvalues, limit=limit, mask=new_mask)
+                return self._simple_new(npvalues.T, new_mask.T)
+            else:
+                # fill with value
+                if copy:
+                    new_values = self.copy()
+                else:
+                    new_values = self[:]
+                new_values[mask] = value
+        else:
+            if copy:
+                new_values = self.copy()
+            else:
+                new_values = self[:]
+        return new_values
+
+    @classmethod
+    def _coerce_to_array(
+        cls, values, *, dtype: DtypeObj, copy: bool = False
+    ) -> tuple[np.ndarray, np.ndarray]:
+        raise AbstractMethodError(cls)
+
+    def _validate_setitem_value(self, value):
+        """
+        Check if we have a scalar that we can cast losslessly.
+
+        Raises
+        ------
+        TypeError
+        """
+        kind = self.dtype.kind
+        # TODO: get this all from np_can_hold_element?
+        if kind == "b":
+            if lib.is_bool(value):
+                return value
+
+        elif kind == "f":
+            if lib.is_integer(value) or lib.is_float(value):
+                return value
+
+        else:
+            if lib.is_integer(value) or (lib.is_float(value) and value.is_integer()):
+                return value
+            # TODO: unsigned checks
+
+        # Note: without the "str" here, the f-string rendering raises in
+        #  py38 builds.
+        raise TypeError(f"Invalid value '{str(value)}' for dtype {self.dtype}")
+
+    def __setitem__(self, key, value) -> None:
+        key = check_array_indexer(self, key)
+
+        if is_scalar(value):
+            if is_valid_na_for_dtype(value, self.dtype):
+                self._mask[key] = True
+            else:
+                value = self._validate_setitem_value(value)
+                self._data[key] = value
+                self._mask[key] = False
+            return
+
+        value, mask = self._coerce_to_array(value, dtype=self.dtype)
+
+        self._data[key] = value
+        self._mask[key] = mask
+
+    def __contains__(self, key) -> bool:
+        if isna(key) and key is not self.dtype.na_value:
+            # GH#52840
+            if self._data.dtype.kind == "f" and lib.is_float(key):
+                return bool((np.isnan(self._data) & ~self._mask).any())
+
+        return bool(super().__contains__(key))
+
+    def __iter__(self) -> Iterator:
+        if self.ndim == 1:
+            if not self._hasna:
+                for val in self._data:
+                    yield val
+            else:
+                na_value = self.dtype.na_value
+                for isna_, val in zip(self._mask, self._data):
+                    if isna_:
+                        yield na_value
+                    else:
+                        yield val
+        else:
+            for i in range(len(self)):
+                yield self[i]
+
+    def __len__(self) -> int:
+        return len(self._data)
+
+    @property
+    def shape(self) -> Shape:
+        return self._data.shape
+
+    @property
+    def ndim(self) -> int:
+        return self._data.ndim
+
+    def swapaxes(self, axis1, axis2) -> Self:
+        data = self._data.swapaxes(axis1, axis2)
+        mask = self._mask.swapaxes(axis1, axis2)
+        return self._simple_new(data, mask)
+
+    def delete(self, loc, axis: AxisInt = 0) -> Self:
+        data = np.delete(self._data, loc, axis=axis)
+        mask = np.delete(self._mask, loc, axis=axis)
+        return self._simple_new(data, mask)
+
+    def reshape(self, *args, **kwargs) -> Self:
+        data = self._data.reshape(*args, **kwargs)
+        mask = self._mask.reshape(*args, **kwargs)
+        return self._simple_new(data, mask)
+
+    def ravel(self, *args, **kwargs) -> Self:
+        # TODO: need to make sure we have the same order for data/mask
+        data = self._data.ravel(*args, **kwargs)
+        mask = self._mask.ravel(*args, **kwargs)
+        return type(self)(data, mask)
+
+    @property
+    def T(self) -> Self:
+        return self._simple_new(self._data.T, self._mask.T)
+
+    def round(self, decimals: int = 0, *args, **kwargs):
+        """
+        Round each value in the array a to the given number of decimals.
+
+        Parameters
+        ----------
+        decimals : int, default 0
+            Number of decimal places to round to. If decimals is negative,
+            it specifies the number of positions to the left of the decimal point.
+        *args, **kwargs
+            Additional arguments and keywords have no effect but might be
+            accepted for compatibility with NumPy.
+
+        Returns
+        -------
+        NumericArray
+            Rounded values of the NumericArray.
+
+        See Also
+        --------
+        numpy.around : Round values of an np.array.
+        DataFrame.round : Round values of a DataFrame.
+        Series.round : Round values of a Series.
+        """
+        if self.dtype.kind == "b":
+            return self
+        nv.validate_round(args, kwargs)
+        values = np.round(self._data, decimals=decimals, **kwargs)
+
+        # Usually we'll get same type as self, but ndarray[bool] casts to float
+        return self._maybe_mask_result(values, self._mask.copy())
+
+    # ------------------------------------------------------------------
+    # Unary Methods
+
+    def __invert__(self) -> Self:
+        return self._simple_new(~self._data, self._mask.copy())
+
+    def __neg__(self) -> Self:
+        return self._simple_new(-self._data, self._mask.copy())
+
+    def __pos__(self) -> Self:
+        return self.copy()
+
+    def __abs__(self) -> Self:
+        return self._simple_new(abs(self._data), self._mask.copy())
+
+    # ------------------------------------------------------------------
+
+    def _values_for_json(self) -> np.ndarray:
+        return np.asarray(self, dtype=object)
+
+    def to_numpy(
+        self,
+        dtype: npt.DTypeLike | None = None,
+        copy: bool = False,
+        na_value: object = lib.no_default,
+    ) -> np.ndarray:
+        """
+        Convert to a NumPy Array.
+
+        By default converts to an object-dtype NumPy array. Specify the `dtype` and
+        `na_value` keywords to customize the conversion.
+
+        Parameters
+        ----------
+        dtype : dtype, default object
+            The numpy dtype to convert to.
+        copy : bool, default False
+            Whether to ensure that the returned value is a not a view on
+            the array. Note that ``copy=False`` does not *ensure* that
+            ``to_numpy()`` is no-copy. Rather, ``copy=True`` ensure that
+            a copy is made, even if not strictly necessary. This is typically
+            only possible when no missing values are present and `dtype`
+            is the equivalent numpy dtype.
+        na_value : scalar, optional
+             Scalar missing value indicator to use in numpy array. Defaults
+             to the native missing value indicator of this array (pd.NA).
+
+        Returns
+        -------
+        numpy.ndarray
+
+        Examples
+        --------
+        An object-dtype is the default result
+
+        >>> a = pd.array([True, False, pd.NA], dtype="boolean")
+        >>> a.to_numpy()
+        array([True, False, <NA>], dtype=object)
+
+        When no missing values are present, an equivalent dtype can be used.
+
+        >>> pd.array([True, False], dtype="boolean").to_numpy(dtype="bool")
+        array([ True, False])
+        >>> pd.array([1, 2], dtype="Int64").to_numpy("int64")
+        array([1, 2])
+
+        However, requesting such dtype will raise a ValueError if
+        missing values are present and the default missing value :attr:`NA`
+        is used.
+
+        >>> a = pd.array([True, False, pd.NA], dtype="boolean")
+        >>> a
+        <BooleanArray>
+        [True, False, <NA>]
+        Length: 3, dtype: boolean
+
+        >>> a.to_numpy(dtype="bool")
+        Traceback (most recent call last):
+        ...
+        ValueError: cannot convert to bool numpy array in presence of missing values
+
+        Specify a valid `na_value` instead
+
+        >>> a.to_numpy(dtype="bool", na_value=False)
+        array([ True, False, False])
+        """
+        hasna = self._hasna
+        dtype, na_value = to_numpy_dtype_inference(self, dtype, na_value, hasna)
+        if dtype is None:
+            dtype = object
+
+        if hasna:
+            if (
+                dtype != object
+                and not is_string_dtype(dtype)
+                and na_value is libmissing.NA
+            ):
+                raise ValueError(
+                    f"cannot convert to '{dtype}'-dtype NumPy array "
+                    "with missing values. Specify an appropriate 'na_value' "
+                    "for this dtype."
+                )
+            # don't pass copy to astype -> always need a copy since we are mutating
+            with warnings.catch_warnings():
+                warnings.filterwarnings("ignore", category=RuntimeWarning)
+                data = self._data.astype(dtype)
+            data[self._mask] = na_value
+        else:
+            with warnings.catch_warnings():
+                warnings.filterwarnings("ignore", category=RuntimeWarning)
+                data = self._data.astype(dtype, copy=copy)
+        return data
+
+    @doc(ExtensionArray.tolist)
+    def tolist(self):
+        if self.ndim > 1:
+            return [x.tolist() for x in self]
+        dtype = None if self._hasna else self._data.dtype
+        return self.to_numpy(dtype=dtype, na_value=libmissing.NA).tolist()
+
+    @overload
+    def astype(self, dtype: npt.DTypeLike, copy: bool = ...) -> np.ndarray:
+        ...
+
+    @overload
+    def astype(self, dtype: ExtensionDtype, copy: bool = ...) -> ExtensionArray:
+        ...
+
+    @overload
+    def astype(self, dtype: AstypeArg, copy: bool = ...) -> ArrayLike:
+        ...
+
+    def astype(self, dtype: AstypeArg, copy: bool = True) -> ArrayLike:
+        dtype = pandas_dtype(dtype)
+
+        if dtype == self.dtype:
+            if copy:
+                return self.copy()
+            return self
+
+        # if we are astyping to another nullable masked dtype, we can fastpath
+        if isinstance(dtype, BaseMaskedDtype):
+            # TODO deal with NaNs for FloatingArray case
+            with warnings.catch_warnings():
+                warnings.filterwarnings("ignore", category=RuntimeWarning)
+                # TODO: Is rounding what we want long term?
+                data = self._data.astype(dtype.numpy_dtype, copy=copy)
+            # mask is copied depending on whether the data was copied, and
+            # not directly depending on the `copy` keyword
+            mask = self._mask if data is self._data else self._mask.copy()
+            cls = dtype.construct_array_type()
+            return cls(data, mask, copy=False)
+
+        if isinstance(dtype, ExtensionDtype):
+            eacls = dtype.construct_array_type()
+            return eacls._from_sequence(self, dtype=dtype, copy=copy)
+
+        na_value: float | np.datetime64 | lib.NoDefault
+
+        # coerce
+        if dtype.kind == "f":
+            # In astype, we consider dtype=float to also mean na_value=np.nan
+            na_value = np.nan
+        elif dtype.kind == "M":
+            na_value = np.datetime64("NaT")
+        else:
+            na_value = lib.no_default
+
+        # to_numpy will also raise, but we get somewhat nicer exception messages here
+        if dtype.kind in "iu" and self._hasna:
+            raise ValueError("cannot convert NA to integer")
+        if dtype.kind == "b" and self._hasna:
+            # careful: astype_nansafe converts np.nan to True
+            raise ValueError("cannot convert float NaN to bool")
+
+        data = self.to_numpy(dtype=dtype, na_value=na_value, copy=copy)
+        return data
+
+    __array_priority__ = 1000  # higher than ndarray so ops dispatch to us
+
+    def __array__(
+        self, dtype: NpDtype | None = None, copy: bool | None = None
+    ) -> np.ndarray:
+        """
+        the array interface, return my values
+        We return an object array here to preserve our scalar values
+        """
+        return self.to_numpy(dtype=dtype)
+
+    _HANDLED_TYPES: tuple[type, ...]
+
+    def __array_ufunc__(self, ufunc: np.ufunc, method: str, *inputs, **kwargs):
+        # For MaskedArray inputs, we apply the ufunc to ._data
+        # and mask the result.
+
+        out = kwargs.get("out", ())
+
+        for x in inputs + out:
+            if not isinstance(x, self._HANDLED_TYPES + (BaseMaskedArray,)):
+                return NotImplemented
+
+        # for binary ops, use our custom dunder methods
+        result = arraylike.maybe_dispatch_ufunc_to_dunder_op(
+            self, ufunc, method, *inputs, **kwargs
+        )
+        if result is not NotImplemented:
+            return result
+
+        if "out" in kwargs:
+            # e.g. test_ufunc_with_out
+            return arraylike.dispatch_ufunc_with_out(
+                self, ufunc, method, *inputs, **kwargs
+            )
+
+        if method == "reduce":
+            result = arraylike.dispatch_reduction_ufunc(
+                self, ufunc, method, *inputs, **kwargs
+            )
+            if result is not NotImplemented:
+                return result
+
+        mask = np.zeros(len(self), dtype=bool)
+        inputs2 = []
+        for x in inputs:
+            if isinstance(x, BaseMaskedArray):
+                mask |= x._mask
+                inputs2.append(x._data)
+            else:
+                inputs2.append(x)
+
+        def reconstruct(x: np.ndarray):
+            # we don't worry about scalar `x` here, since we
+            # raise for reduce up above.
+            from pandas.core.arrays import (
+                BooleanArray,
+                FloatingArray,
+                IntegerArray,
+            )
+
+            if x.dtype.kind == "b":
+                m = mask.copy()
+                return BooleanArray(x, m)
+            elif x.dtype.kind in "iu":
+                m = mask.copy()
+                return IntegerArray(x, m)
+            elif x.dtype.kind == "f":
+                m = mask.copy()
+                if x.dtype == np.float16:
+                    # reached in e.g. np.sqrt on BooleanArray
+                    # we don't support float16
+                    x = x.astype(np.float32)
+                return FloatingArray(x, m)
+            else:
+                x[mask] = np.nan
+            return x
+
+        result = getattr(ufunc, method)(*inputs2, **kwargs)
+        if ufunc.nout > 1:
+            # e.g. np.divmod
+            return tuple(reconstruct(x) for x in result)
+        elif method == "reduce":
+            # e.g. np.add.reduce; test_ufunc_reduce_raises
+            if self._mask.any():
+                return self._na_value
+            return result
+        else:
+            return reconstruct(result)
+
+    def __arrow_array__(self, type=None):
+        """
+        Convert myself into a pyarrow Array.
+        """
+        import pyarrow as pa
+
+        return pa.array(self._data, mask=self._mask, type=type)
+
+    @property
+    def _hasna(self) -> bool:
+        # Note: this is expensive right now! The hope is that we can
+        # make this faster by having an optional mask, but not have to change
+        # source code using it..
+
+        # error: Incompatible return value type (got "bool_", expected "bool")
+        return self._mask.any()  # type: ignore[return-value]
+
+    def _propagate_mask(
+        self, mask: npt.NDArray[np.bool_] | None, other
+    ) -> npt.NDArray[np.bool_]:
+        if mask is None:
+            mask = self._mask.copy()  # TODO: need test for BooleanArray needing a copy
+            if other is libmissing.NA:
+                # GH#45421 don't alter inplace
+                mask = mask | True
+            elif is_list_like(other) and len(other) == len(mask):
+                mask = mask | isna(other)
+        else:
+            mask = self._mask | mask
+        # Incompatible return value type (got "Optional[ndarray[Any, dtype[bool_]]]",
+        # expected "ndarray[Any, dtype[bool_]]")
+        return mask  # type: ignore[return-value]
+
+    def _arith_method(self, other, op):
+        op_name = op.__name__
+        omask = None
+
+        if (
+            not hasattr(other, "dtype")
+            and is_list_like(other)
+            and len(other) == len(self)
+        ):
+            # Try inferring masked dtype instead of casting to object
+            other = pd_array(other)
+            other = extract_array(other, extract_numpy=True)
+
+        if isinstance(other, BaseMaskedArray):
+            other, omask = other._data, other._mask
+
+        elif is_list_like(other):
+            if not isinstance(other, ExtensionArray):
+                other = np.asarray(other)
+            if other.ndim > 1:
+                raise NotImplementedError("can only perform ops with 1-d structures")
+
+        # We wrap the non-masked arithmetic logic used for numpy dtypes
+        #  in Series/Index arithmetic ops.
+        other = ops.maybe_prepare_scalar_for_op(other, (len(self),))
+        pd_op = ops.get_array_op(op)
+        other = ensure_wrapped_if_datetimelike(other)
+
+        if op_name in {"pow", "rpow"} and isinstance(other, np.bool_):
+            # Avoid DeprecationWarning: In future, it will be an error
+            #  for 'np.bool_' scalars to be interpreted as an index
+            #  e.g. test_array_scalar_like_equivalence
+            other = bool(other)
+
+        mask = self._propagate_mask(omask, other)
+
+        if other is libmissing.NA:
+            result = np.ones_like(self._data)
+            if self.dtype.kind == "b":
+                if op_name in {
+                    "floordiv",
+                    "rfloordiv",
+                    "pow",
+                    "rpow",
+                    "truediv",
+                    "rtruediv",
+                }:
+                    # GH#41165 Try to match non-masked Series behavior
+                    #  This is still imperfect GH#46043
+                    raise NotImplementedError(
+                        f"operator '{op_name}' not implemented for bool dtypes"
+                    )
+                if op_name in {"mod", "rmod"}:
+                    dtype = "int8"
+                else:
+                    dtype = "bool"
+                result = result.astype(dtype)
+            elif "truediv" in op_name and self.dtype.kind != "f":
+                # The actual data here doesn't matter since the mask
+                #  will be all-True, but since this is division, we want
+                #  to end up with floating dtype.
+                result = result.astype(np.float64)
+        else:
+            # Make sure we do this before the "pow" mask checks
+            #  to get an expected exception message on shape mismatch.
+            if self.dtype.kind in "iu" and op_name in ["floordiv", "mod"]:
+                # TODO(GH#30188) ATM we don't match the behavior of non-masked
+                #  types with respect to floordiv-by-zero
+                pd_op = op
+
+            with np.errstate(all="ignore"):
+                result = pd_op(self._data, other)
+
+        if op_name == "pow":
+            # 1 ** x is 1.
+            mask = np.where((self._data == 1) & ~self._mask, False, mask)
+            # x ** 0 is 1.
+            if omask is not None:
+                mask = np.where((other == 0) & ~omask, False, mask)
+            elif other is not libmissing.NA:
+                mask = np.where(other == 0, False, mask)
+
+        elif op_name == "rpow":
+            # 1 ** x is 1.
+            if omask is not None:
+                mask = np.where((other == 1) & ~omask, False, mask)
+            elif other is not libmissing.NA:
+                mask = np.where(other == 1, False, mask)
+            # x ** 0 is 1.
+            mask = np.where((self._data == 0) & ~self._mask, False, mask)
+
+        return self._maybe_mask_result(result, mask)
+
+    _logical_method = _arith_method
+
+    def _cmp_method(self, other, op) -> BooleanArray:
+        from pandas.core.arrays import BooleanArray
+
+        mask = None
+
+        if isinstance(other, BaseMaskedArray):
+            other, mask = other._data, other._mask
+
+        elif is_list_like(other):
+            other = np.asarray(other)
+            if other.ndim > 1:
+                raise NotImplementedError("can only perform ops with 1-d structures")
+            if len(self) != len(other):
+                raise ValueError("Lengths must match to compare")
+
+        if other is libmissing.NA:
+            # numpy does not handle pd.NA well as "other" scalar (it returns
+            # a scalar False instead of an array)
+            # This may be fixed by NA.__array_ufunc__. Revisit this check
+            # once that's implemented.
+            result = np.zeros(self._data.shape, dtype="bool")
+            mask = np.ones(self._data.shape, dtype="bool")
+        else:
+            with warnings.catch_warnings():
+                # numpy may show a FutureWarning or DeprecationWarning:
+                #     elementwise comparison failed; returning scalar instead,
+                #     but in the future will perform elementwise comparison
+                # before returning NotImplemented. We fall back to the correct
+                # behavior today, so that should be fine to ignore.
+                warnings.filterwarnings("ignore", "elementwise", FutureWarning)
+                warnings.filterwarnings("ignore", "elementwise", DeprecationWarning)
+                method = getattr(self._data, f"__{op.__name__}__")
+                result = method(other)
+
+                if result is NotImplemented:
+                    result = invalid_comparison(self._data, other, op)
+
+        mask = self._propagate_mask(mask, other)
+        return BooleanArray(result, mask, copy=False)
+
+    def _maybe_mask_result(
+        self, result: np.ndarray | tuple[np.ndarray, np.ndarray], mask: np.ndarray
+    ):
+        """
+        Parameters
+        ----------
+        result : array-like or tuple[array-like]
+        mask : array-like bool
+        """
+        if isinstance(result, tuple):
+            # i.e. divmod
+            div, mod = result
+            return (
+                self._maybe_mask_result(div, mask),
+                self._maybe_mask_result(mod, mask),
+            )
+
+        if result.dtype.kind == "f":
+            from pandas.core.arrays import FloatingArray
+
+            return FloatingArray(result, mask, copy=False)
+
+        elif result.dtype.kind == "b":
+            from pandas.core.arrays import BooleanArray
+
+            return BooleanArray(result, mask, copy=False)
+
+        elif lib.is_np_dtype(result.dtype, "m") and is_supported_dtype(result.dtype):
+            # e.g. test_numeric_arr_mul_tdscalar_numexpr_path
+            from pandas.core.arrays import TimedeltaArray
+
+            result[mask] = result.dtype.type("NaT")
+
+            if not isinstance(result, TimedeltaArray):
+                return TimedeltaArray._simple_new(result, dtype=result.dtype)
+
+            return result
+
+        elif result.dtype.kind in "iu":
+            from pandas.core.arrays import IntegerArray
+
+            return IntegerArray(result, mask, copy=False)
+
+        else:
+            result[mask] = np.nan
+            return result
+
+    def isna(self) -> np.ndarray:
+        return self._mask.copy()
+
+    @property
+    def _na_value(self):
+        return self.dtype.na_value
+
+    @property
+    def nbytes(self) -> int:
+        return self._data.nbytes + self._mask.nbytes
+
+    @classmethod
+    def _concat_same_type(
+        cls,
+        to_concat: Sequence[Self],
+        axis: AxisInt = 0,
+    ) -> Self:
+        data = np.concatenate([x._data for x in to_concat], axis=axis)
+        mask = np.concatenate([x._mask for x in to_concat], axis=axis)
+        return cls(data, mask)
+
+    def _hash_pandas_object(
+        self, *, encoding: str, hash_key: str, categorize: bool
+    ) -> npt.NDArray[np.uint64]:
+        hashed_array = hash_array(
+            self._data, encoding=encoding, hash_key=hash_key, categorize=categorize
+        )
+        hashed_array[self.isna()] = hash(self.dtype.na_value)
+        return hashed_array
+
+    def take(
+        self,
+        indexer,
+        *,
+        allow_fill: bool = False,
+        fill_value: Scalar | None = None,
+        axis: AxisInt = 0,
+    ) -> Self:
+        # we always fill with 1 internally
+        # to avoid upcasting
+        data_fill_value = self._internal_fill_value if isna(fill_value) else fill_value
+        result = take(
+            self._data,
+            indexer,
+            fill_value=data_fill_value,
+            allow_fill=allow_fill,
+            axis=axis,
+        )
+
+        mask = take(
+            self._mask, indexer, fill_value=True, allow_fill=allow_fill, axis=axis
+        )
+
+        # if we are filling
+        # we only fill where the indexer is null
+        # not existing missing values
+        # TODO(jreback) what if we have a non-na float as a fill value?
+        if allow_fill and notna(fill_value):
+            fill_mask = np.asarray(indexer) == -1
+            result[fill_mask] = fill_value
+            mask = mask ^ fill_mask
+
+        return self._simple_new(result, mask)
+
+    # error: Return type "BooleanArray" of "isin" incompatible with return type
+    # "ndarray" in supertype "ExtensionArray"
+    def isin(self, values: ArrayLike) -> BooleanArray:  # type: ignore[override]
+        from pandas.core.arrays import BooleanArray
+
+        # algorithms.isin will eventually convert values to an ndarray, so no extra
+        # cost to doing it here first
+        values_arr = np.asarray(values)
+        result = isin(self._data, values_arr)
+
+        if self._hasna:
+            values_have_NA = values_arr.dtype == object and any(
+                val is self.dtype.na_value for val in values_arr
+            )
+
+            # For now, NA does not propagate so set result according to presence of NA,
+            # see https://github.com/pandas-dev/pandas/pull/38379 for some discussion
+            result[self._mask] = values_have_NA
+
+        mask = np.zeros(self._data.shape, dtype=bool)
+        return BooleanArray(result, mask, copy=False)
+
+    def copy(self) -> Self:
+        data = self._data.copy()
+        mask = self._mask.copy()
+        return self._simple_new(data, mask)
+
+    @doc(ExtensionArray.duplicated)
+    def duplicated(
+        self, keep: Literal["first", "last", False] = "first"
+    ) -> npt.NDArray[np.bool_]:
+        values = self._data
+        mask = self._mask
+        return algos.duplicated(values, keep=keep, mask=mask)
+
+    def unique(self) -> Self:
+        """
+        Compute the BaseMaskedArray of unique values.
+
+        Returns
+        -------
+        uniques : BaseMaskedArray
+        """
+        uniques, mask = algos.unique_with_mask(self._data, self._mask)
+        return self._simple_new(uniques, mask)
+
+    @doc(ExtensionArray.searchsorted)
+    def searchsorted(
+        self,
+        value: NumpyValueArrayLike | ExtensionArray,
+        side: Literal["left", "right"] = "left",
+        sorter: NumpySorter | None = None,
+    ) -> npt.NDArray[np.intp] | np.intp:
+        if self._hasna:
+            raise ValueError(
+                "searchsorted requires array to be sorted, which is impossible "
+                "with NAs present."
+            )
+        if isinstance(value, ExtensionArray):
+            value = value.astype(object)
+        # Base class searchsorted would cast to object, which is *much* slower.
+        return self._data.searchsorted(value, side=side, sorter=sorter)
+
+    @doc(ExtensionArray.factorize)
+    def factorize(
+        self,
+        use_na_sentinel: bool = True,
+    ) -> tuple[np.ndarray, ExtensionArray]:
+        arr = self._data
+        mask = self._mask
+
+        # Use a sentinel for na; recode and add NA to uniques if necessary below
+        codes, uniques = factorize_array(arr, use_na_sentinel=True, mask=mask)
+
+        # check that factorize_array correctly preserves dtype.
+        assert uniques.dtype == self.dtype.numpy_dtype, (uniques.dtype, self.dtype)
+
+        has_na = mask.any()
+        if use_na_sentinel or not has_na:
+            size = len(uniques)
+        else:
+            # Make room for an NA value
+            size = len(uniques) + 1
+        uniques_mask = np.zeros(size, dtype=bool)
+        if not use_na_sentinel and has_na:
+            na_index = mask.argmax()
+            # Insert na with the proper code
+            if na_index == 0:
+                na_code = np.intp(0)
+            else:
+                na_code = codes[:na_index].max() + 1
+            codes[codes >= na_code] += 1
+            codes[codes == -1] = na_code
+            # dummy value for uniques; not used since uniques_mask will be True
+            uniques = np.insert(uniques, na_code, 0)
+            uniques_mask[na_code] = True
+        uniques_ea = self._simple_new(uniques, uniques_mask)
+
+        return codes, uniques_ea
+
+    @doc(ExtensionArray._values_for_argsort)
+    def _values_for_argsort(self) -> np.ndarray:
+        return self._data
+
+    def value_counts(self, dropna: bool = True) -> Series:
+        """
+        Returns a Series containing counts of each unique value.
+
+        Parameters
+        ----------
+        dropna : bool, default True
+            Don't include counts of missing values.
+
+        Returns
+        -------
+        counts : Series
+
+        See Also
+        --------
+        Series.value_counts
+        """
+        from pandas import (
+            Index,
+            Series,
+        )
+        from pandas.arrays import IntegerArray
+
+        keys, value_counts, na_counter = algos.value_counts_arraylike(
+            self._data, dropna=dropna, mask=self._mask
+        )
+        mask_index = np.zeros((len(value_counts),), dtype=np.bool_)
+        mask = mask_index.copy()
+
+        if na_counter > 0:
+            mask_index[-1] = True
+
+        arr = IntegerArray(value_counts, mask)
+        index = Index(
+            self.dtype.construct_array_type()(
+                keys, mask_index  # type: ignore[arg-type]
+            )
+        )
+        return Series(arr, index=index, name="count", copy=False)
+
+    def _mode(self, dropna: bool = True) -> Self:
+        if dropna:
+            result = mode(self._data, dropna=dropna, mask=self._mask)
+            res_mask = np.zeros(result.shape, dtype=np.bool_)
+        else:
+            result, res_mask = mode(self._data, dropna=dropna, mask=self._mask)
+        result = type(self)(result, res_mask)  # type: ignore[arg-type]
+        return result[result.argsort()]
+
+    @doc(ExtensionArray.equals)
+    def equals(self, other) -> bool:
+        if type(self) != type(other):
+            return False
+        if other.dtype != self.dtype:
+            return False
+
+        # GH#44382 if e.g. self[1] is np.nan and other[1] is pd.NA, we are NOT
+        #  equal.
+        if not np.array_equal(self._mask, other._mask):
+            return False
+
+        left = self._data[~self._mask]
+        right = other._data[~other._mask]
+        return array_equivalent(left, right, strict_nan=True, dtype_equal=True)
+
+    def _quantile(
+        self, qs: npt.NDArray[np.float64], interpolation: str
+    ) -> BaseMaskedArray:
+        """
+        Dispatch to quantile_with_mask, needed because we do not have
+        _from_factorized.
+
+        Notes
+        -----
+        We assume that all impacted cases are 1D-only.
+        """
+        res = quantile_with_mask(
+            self._data,
+            mask=self._mask,
+            # TODO(GH#40932): na_value_for_dtype(self.dtype.numpy_dtype)
+            #  instead of np.nan
+            fill_value=np.nan,
+            qs=qs,
+            interpolation=interpolation,
+        )
+
+        if self._hasna:
+            # Our result mask is all-False unless we are all-NA, in which
+            #  case it is all-True.
+            if self.ndim == 2:
+                # I think this should be out_mask=self.isna().all(axis=1)
+                #  but am holding off until we have tests
+                raise NotImplementedError
+            if self.isna().all():
+                out_mask = np.ones(res.shape, dtype=bool)
+
+                if is_integer_dtype(self.dtype):
+                    # We try to maintain int dtype if possible for not all-na case
+                    # as well
+                    res = np.zeros(res.shape, dtype=self.dtype.numpy_dtype)
+            else:
+                out_mask = np.zeros(res.shape, dtype=bool)
+        else:
+            out_mask = np.zeros(res.shape, dtype=bool)
+        return self._maybe_mask_result(res, mask=out_mask)
+
+    # ------------------------------------------------------------------
+    # Reductions
+
+    def _reduce(
+        self, name: str, *, skipna: bool = True, keepdims: bool = False, **kwargs
+    ):
+        if name in {"any", "all", "min", "max", "sum", "prod", "mean", "var", "std"}:
+            result = getattr(self, name)(skipna=skipna, **kwargs)
+        else:
+            # median, skew, kurt, sem
+            data = self._data
+            mask = self._mask
+            op = getattr(nanops, f"nan{name}")
+            axis = kwargs.pop("axis", None)
+            result = op(data, axis=axis, skipna=skipna, mask=mask, **kwargs)
+
+        if keepdims:
+            if isna(result):
+                return self._wrap_na_result(name=name, axis=0, mask_size=(1,))
+            else:
+                result = result.reshape(1)
+                mask = np.zeros(1, dtype=bool)
+                return self._maybe_mask_result(result, mask)
+
+        if isna(result):
+            return libmissing.NA
+        else:
+            return result
+
+    def _wrap_reduction_result(self, name: str, result, *, skipna, axis):
+        if isinstance(result, np.ndarray):
+            if skipna:
+                # we only retain mask for all-NA rows/columns
+                mask = self._mask.all(axis=axis)
+            else:
+                mask = self._mask.any(axis=axis)
+
+            return self._maybe_mask_result(result, mask)
+        return result
+
+    def _wrap_na_result(self, *, name, axis, mask_size):
+        mask = np.ones(mask_size, dtype=bool)
+
+        float_dtyp = "float32" if self.dtype == "Float32" else "float64"
+        if name in ["mean", "median", "var", "std", "skew", "kurt"]:
+            np_dtype = float_dtyp
+        elif name in ["min", "max"] or self.dtype.itemsize == 8:
+            np_dtype = self.dtype.numpy_dtype.name
+        else:
+            is_windows_or_32bit = is_platform_windows() or not IS64
+            int_dtyp = "int32" if is_windows_or_32bit else "int64"
+            uint_dtyp = "uint32" if is_windows_or_32bit else "uint64"
+            np_dtype = {"b": int_dtyp, "i": int_dtyp, "u": uint_dtyp, "f": float_dtyp}[
+                self.dtype.kind
+            ]
+
+        value = np.array([1], dtype=np_dtype)
+        return self._maybe_mask_result(value, mask=mask)
+
+    def _wrap_min_count_reduction_result(
+        self, name: str, result, *, skipna, min_count, axis
+    ):
+        if min_count == 0 and isinstance(result, np.ndarray):
+            return self._maybe_mask_result(result, np.zeros(result.shape, dtype=bool))
+        return self._wrap_reduction_result(name, result, skipna=skipna, axis=axis)
+
+    def sum(
+        self,
+        *,
+        skipna: bool = True,
+        min_count: int = 0,
+        axis: AxisInt | None = 0,
+        **kwargs,
+    ):
+        nv.validate_sum((), kwargs)
+
+        result = masked_reductions.sum(
+            self._data,
+            self._mask,
+            skipna=skipna,
+            min_count=min_count,
+            axis=axis,
+        )
+        return self._wrap_min_count_reduction_result(
+            "sum", result, skipna=skipna, min_count=min_count, axis=axis
+        )
+
+    def prod(
+        self,
+        *,
+        skipna: bool = True,
+        min_count: int = 0,
+        axis: AxisInt | None = 0,
+        **kwargs,
+    ):
+        nv.validate_prod((), kwargs)
+
+        result = masked_reductions.prod(
+            self._data,
+            self._mask,
+            skipna=skipna,
+            min_count=min_count,
+            axis=axis,
+        )
+        return self._wrap_min_count_reduction_result(
+            "prod", result, skipna=skipna, min_count=min_count, axis=axis
+        )
+
+    def mean(self, *, skipna: bool = True, axis: AxisInt | None = 0, **kwargs):
+        nv.validate_mean((), kwargs)
+        result = masked_reductions.mean(
+            self._data,
+            self._mask,
+            skipna=skipna,
+            axis=axis,
+        )
+        return self._wrap_reduction_result("mean", result, skipna=skipna, axis=axis)
+
+    def var(
+        self, *, skipna: bool = True, axis: AxisInt | None = 0, ddof: int = 1, **kwargs
+    ):
+        nv.validate_stat_ddof_func((), kwargs, fname="var")
+        result = masked_reductions.var(
+            self._data,
+            self._mask,
+            skipna=skipna,
+            axis=axis,
+            ddof=ddof,
+        )
+        return self._wrap_reduction_result("var", result, skipna=skipna, axis=axis)
+
+    def std(
+        self, *, skipna: bool = True, axis: AxisInt | None = 0, ddof: int = 1, **kwargs
+    ):
+        nv.validate_stat_ddof_func((), kwargs, fname="std")
+        result = masked_reductions.std(
+            self._data,
+            self._mask,
+            skipna=skipna,
+            axis=axis,
+            ddof=ddof,
+        )
+        return self._wrap_reduction_result("std", result, skipna=skipna, axis=axis)
+
+    def min(self, *, skipna: bool = True, axis: AxisInt | None = 0, **kwargs):
+        nv.validate_min((), kwargs)
+        result = masked_reductions.min(
+            self._data,
+            self._mask,
+            skipna=skipna,
+            axis=axis,
+        )
+        return self._wrap_reduction_result("min", result, skipna=skipna, axis=axis)
+
+    def max(self, *, skipna: bool = True, axis: AxisInt | None = 0, **kwargs):
+        nv.validate_max((), kwargs)
+        result = masked_reductions.max(
+            self._data,
+            self._mask,
+            skipna=skipna,
+            axis=axis,
+        )
+        return self._wrap_reduction_result("max", result, skipna=skipna, axis=axis)
+
+    def map(self, mapper, na_action=None):
+        return map_array(self.to_numpy(), mapper, na_action=na_action)
+
+    def any(self, *, skipna: bool = True, axis: AxisInt | None = 0, **kwargs):
+        """
+        Return whether any element is truthy.
+
+        Returns False unless there is at least one element that is truthy.
+        By default, NAs are skipped. If ``skipna=False`` is specified and
+        missing values are present, similar :ref:`Kleene logic <boolean.kleene>`
+        is used as for logical operations.
+
+        .. versionchanged:: 1.4.0
+
+        Parameters
+        ----------
+        skipna : bool, default True
+            Exclude NA values. If the entire array is NA and `skipna` is
+            True, then the result will be False, as for an empty array.
+            If `skipna` is False, the result will still be True if there is
+            at least one element that is truthy, otherwise NA will be returned
+            if there are NA's present.
+        axis : int, optional, default 0
+        **kwargs : any, default None
+            Additional keywords have no effect but might be accepted for
+            compatibility with NumPy.
+
+        Returns
+        -------
+        bool or :attr:`pandas.NA`
+
+        See Also
+        --------
+        numpy.any : Numpy version of this method.
+        BaseMaskedArray.all : Return whether all elements are truthy.
+
+        Examples
+        --------
+        The result indicates whether any element is truthy (and by default
+        skips NAs):
+
+        >>> pd.array([True, False, True]).any()
+        True
+        >>> pd.array([True, False, pd.NA]).any()
+        True
+        >>> pd.array([False, False, pd.NA]).any()
+        False
+        >>> pd.array([], dtype="boolean").any()
+        False
+        >>> pd.array([pd.NA], dtype="boolean").any()
+        False
+        >>> pd.array([pd.NA], dtype="Float64").any()
+        False
+
+        With ``skipna=False``, the result can be NA if this is logically
+        required (whether ``pd.NA`` is True or False influences the result):
+
+        >>> pd.array([True, False, pd.NA]).any(skipna=False)
+        True
+        >>> pd.array([1, 0, pd.NA]).any(skipna=False)
+        True
+        >>> pd.array([False, False, pd.NA]).any(skipna=False)
+        <NA>
+        >>> pd.array([0, 0, pd.NA]).any(skipna=False)
+        <NA>
+        """
+        nv.validate_any((), kwargs)
+
+        values = self._data.copy()
+        # error: Argument 3 to "putmask" has incompatible type "object";
+        # expected "Union[_SupportsArray[dtype[Any]],
+        # _NestedSequence[_SupportsArray[dtype[Any]]],
+        # bool, int, float, complex, str, bytes,
+        # _NestedSequence[Union[bool, int, float, complex, str, bytes]]]"
+        np.putmask(values, self._mask, self._falsey_value)  # type: ignore[arg-type]
+        result = values.any()
+        if skipna:
+            return result
+        else:
+            if result or len(self) == 0 or not self._mask.any():
+                return result
+            else:
+                return self.dtype.na_value
+
+    def all(self, *, skipna: bool = True, axis: AxisInt | None = 0, **kwargs):
+        """
+        Return whether all elements are truthy.
+
+        Returns True unless there is at least one element that is falsey.
+        By default, NAs are skipped. If ``skipna=False`` is specified and
+        missing values are present, similar :ref:`Kleene logic <boolean.kleene>`
+        is used as for logical operations.
+
+        .. versionchanged:: 1.4.0
+
+        Parameters
+        ----------
+        skipna : bool, default True
+            Exclude NA values. If the entire array is NA and `skipna` is
+            True, then the result will be True, as for an empty array.
+            If `skipna` is False, the result will still be False if there is
+            at least one element that is falsey, otherwise NA will be returned
+            if there are NA's present.
+        axis : int, optional, default 0
+        **kwargs : any, default None
+            Additional keywords have no effect but might be accepted for
+            compatibility with NumPy.
+
+        Returns
+        -------
+        bool or :attr:`pandas.NA`
+
+        See Also
+        --------
+        numpy.all : Numpy version of this method.
+        BooleanArray.any : Return whether any element is truthy.
+
+        Examples
+        --------
+        The result indicates whether all elements are truthy (and by default
+        skips NAs):
+
+        >>> pd.array([True, True, pd.NA]).all()
+        True
+        >>> pd.array([1, 1, pd.NA]).all()
+        True
+        >>> pd.array([True, False, pd.NA]).all()
+        False
+        >>> pd.array([], dtype="boolean").all()
+        True
+        >>> pd.array([pd.NA], dtype="boolean").all()
+        True
+        >>> pd.array([pd.NA], dtype="Float64").all()
+        True
+
+        With ``skipna=False``, the result can be NA if this is logically
+        required (whether ``pd.NA`` is True or False influences the result):
+
+        >>> pd.array([True, True, pd.NA]).all(skipna=False)
+        <NA>
+        >>> pd.array([1, 1, pd.NA]).all(skipna=False)
+        <NA>
+        >>> pd.array([True, False, pd.NA]).all(skipna=False)
+        False
+        >>> pd.array([1, 0, pd.NA]).all(skipna=False)
+        False
+        """
+        nv.validate_all((), kwargs)
+
+        values = self._data.copy()
+        # error: Argument 3 to "putmask" has incompatible type "object";
+        # expected "Union[_SupportsArray[dtype[Any]],
+        # _NestedSequence[_SupportsArray[dtype[Any]]],
+        # bool, int, float, complex, str, bytes,
+        # _NestedSequence[Union[bool, int, float, complex, str, bytes]]]"
+        np.putmask(values, self._mask, self._truthy_value)  # type: ignore[arg-type]
+        result = values.all(axis=axis)
+
+        if skipna:
+            return result
+        else:
+            if not result or len(self) == 0 or not self._mask.any():
+                return result
+            else:
+                return self.dtype.na_value
+
+    def interpolate(
+        self,
+        *,
+        method: InterpolateOptions,
+        axis: int,
+        index,
+        limit,
+        limit_direction,
+        limit_area,
+        copy: bool,
+        **kwargs,
+    ) -> FloatingArray:
+        """
+        See NDFrame.interpolate.__doc__.
+        """
+        # NB: we return type(self) even if copy=False
+        if self.dtype.kind == "f":
+            if copy:
+                data = self._data.copy()
+                mask = self._mask.copy()
+            else:
+                data = self._data
+                mask = self._mask
+        elif self.dtype.kind in "iu":
+            copy = True
+            data = self._data.astype("f8")
+            mask = self._mask.copy()
+        else:
+            raise NotImplementedError(
+                f"interpolate is not implemented for dtype={self.dtype}"
+            )
+
+        missing.interpolate_2d_inplace(
+            data,
+            method=method,
+            axis=0,
+            index=index,
+            limit=limit,
+            limit_direction=limit_direction,
+            limit_area=limit_area,
+            mask=mask,
+            **kwargs,
+        )
+        if not copy:
+            return self  # type: ignore[return-value]
+        if self.dtype.kind == "f":
+            return type(self)._simple_new(data, mask)  # type: ignore[return-value]
+        else:
+            from pandas.core.arrays import FloatingArray
+
+            return FloatingArray._simple_new(data, mask)
+
+    def _accumulate(
+        self, name: str, *, skipna: bool = True, **kwargs
+    ) -> BaseMaskedArray:
+        data = self._data
+        mask = self._mask
+
+        op = getattr(masked_accumulations, name)
+        data, mask = op(data, mask, skipna=skipna, **kwargs)
+
+        return self._simple_new(data, mask)
+
+    # ------------------------------------------------------------------
+    # GroupBy Methods
+
+    def _groupby_op(
+        self,
+        *,
+        how: str,
+        has_dropped_na: bool,
+        min_count: int,
+        ngroups: int,
+        ids: npt.NDArray[np.intp],
+        **kwargs,
+    ):
+        from pandas.core.groupby.ops import WrappedCythonOp
+
+        kind = WrappedCythonOp.get_kind_from_how(how)
+        op = WrappedCythonOp(how=how, kind=kind, has_dropped_na=has_dropped_na)
+
+        # libgroupby functions are responsible for NOT altering mask
+        mask = self._mask
+        if op.kind != "aggregate":
+            result_mask = mask.copy()
+        else:
+            result_mask = np.zeros(ngroups, dtype=bool)
+
+        if how == "rank" and kwargs.get("na_option") in ["top", "bottom"]:
+            result_mask[:] = False
+
+        res_values = op._cython_op_ndim_compat(
+            self._data,
+            min_count=min_count,
+            ngroups=ngroups,
+            comp_ids=ids,
+            mask=mask,
+            result_mask=result_mask,
+            **kwargs,
+        )
+
+        if op.how == "ohlc":
+            arity = op._cython_arity.get(op.how, 1)
+            result_mask = np.tile(result_mask, (arity, 1)).T
+
+        if op.how in ["idxmin", "idxmax"]:
+            # Result values are indexes to take, keep as ndarray
+            return res_values
+        else:
+            # res_values should already have the correct dtype, we just need to
+            #  wrap in a MaskedArray
+            return self._maybe_mask_result(res_values, result_mask)
+
+
+def transpose_homogeneous_masked_arrays(
+    masked_arrays: Sequence[BaseMaskedArray],
+) -> list[BaseMaskedArray]:
+    """Transpose masked arrays in a list, but faster.
+
+    Input should be a list of 1-dim masked arrays of equal length and all have the
+    same dtype. The caller is responsible for ensuring validity of input data.
+    """
+    masked_arrays = list(masked_arrays)
+    dtype = masked_arrays[0].dtype
+
+    values = [arr._data.reshape(1, -1) for arr in masked_arrays]
+    transposed_values = np.concatenate(
+        values,
+        axis=0,
+        out=np.empty(
+            (len(masked_arrays), len(masked_arrays[0])),
+            order="F",
+            dtype=dtype.numpy_dtype,
+        ),
+    )
+
+    masks = [arr._mask.reshape(1, -1) for arr in masked_arrays]
+    transposed_masks = np.concatenate(
+        masks, axis=0, out=np.empty_like(transposed_values, dtype=bool)
+    )
+
+    arr_type = dtype.construct_array_type()
+    transposed_arrays: list[BaseMaskedArray] = []
+    for i in range(transposed_values.shape[1]):
+        transposed_arr = arr_type(transposed_values[:, i], mask=transposed_masks[:, i])
+        transposed_arrays.append(transposed_arr)
+
+    return transposed_arrays

venv/lib/python3.10/site-packages/pandas/core/arrays/numpy_.py

@@ -0,0 +1,563 @@
+from __future__ import annotations
+
+from typing import (
+    TYPE_CHECKING,
+    Literal,
+)
+
+import numpy as np
+
+from pandas._libs import lib
+from pandas._libs.tslibs import is_supported_dtype
+from pandas.compat.numpy import function as nv
+
+from pandas.core.dtypes.astype import astype_array
+from pandas.core.dtypes.cast import construct_1d_object_array_from_listlike
+from pandas.core.dtypes.common import pandas_dtype
+from pandas.core.dtypes.dtypes import NumpyEADtype
+from pandas.core.dtypes.missing import isna
+
+from pandas.core import (
+    arraylike,
+    missing,
+    nanops,
+    ops,
+)
+from pandas.core.arraylike import OpsMixin
+from pandas.core.arrays._mixins import NDArrayBackedExtensionArray
+from pandas.core.construction import ensure_wrapped_if_datetimelike
+from pandas.core.strings.object_array import ObjectStringArrayMixin
+
+if TYPE_CHECKING:
+    from pandas._typing import (
+        AxisInt,
+        Dtype,
+        FillnaOptions,
+        InterpolateOptions,
+        NpDtype,
+        Scalar,
+        Self,
+        npt,
+    )
+
+    from pandas import Index
+
+
+# error: Definition of "_concat_same_type" in base class "NDArrayBacked" is
+# incompatible with definition in base class "ExtensionArray"
+class NumpyExtensionArray(  # type: ignore[misc]
+    OpsMixin,
+    NDArrayBackedExtensionArray,
+    ObjectStringArrayMixin,
+):
+    """
+    A pandas ExtensionArray for NumPy data.
+
+    This is mostly for internal compatibility, and is not especially
+    useful on its own.
+
+    Parameters
+    ----------
+    values : ndarray
+        The NumPy ndarray to wrap. Must be 1-dimensional.
+    copy : bool, default False
+        Whether to copy `values`.
+
+    Attributes
+    ----------
+    None
+
+    Methods
+    -------
+    None
+
+    Examples
+    --------
+    >>> pd.arrays.NumpyExtensionArray(np.array([0, 1, 2, 3]))
+    <NumpyExtensionArray>
+    [0, 1, 2, 3]
+    Length: 4, dtype: int64
+    """
+
+    # If you're wondering why pd.Series(cls) doesn't put the array in an
+    # ExtensionBlock, search for `ABCNumpyExtensionArray`. We check for
+    # that _typ to ensure that users don't unnecessarily use EAs inside
+    # pandas internals, which turns off things like block consolidation.
+    _typ = "npy_extension"
+    __array_priority__ = 1000
+    _ndarray: np.ndarray
+    _dtype: NumpyEADtype
+    _internal_fill_value = np.nan
+
+    # ------------------------------------------------------------------------
+    # Constructors
+
+    def __init__(
+        self, values: np.ndarray | NumpyExtensionArray, copy: bool = False
+    ) -> None:
+        if isinstance(values, type(self)):
+            values = values._ndarray
+        if not isinstance(values, np.ndarray):
+            raise ValueError(
+                f"'values' must be a NumPy array, not {type(values).__name__}"
+            )
+
+        if values.ndim == 0:
+            # Technically we support 2, but do not advertise that fact.
+            raise ValueError("NumpyExtensionArray must be 1-dimensional.")
+
+        if copy:
+            values = values.copy()
+
+        dtype = NumpyEADtype(values.dtype)
+        super().__init__(values, dtype)
+
+    @classmethod
+    def _from_sequence(
+        cls, scalars, *, dtype: Dtype | None = None, copy: bool = False
+    ) -> NumpyExtensionArray:
+        if isinstance(dtype, NumpyEADtype):
+            dtype = dtype._dtype
+
+        # error: Argument "dtype" to "asarray" has incompatible type
+        # "Union[ExtensionDtype, str, dtype[Any], dtype[floating[_64Bit]], Type[object],
+        # None]"; expected "Union[dtype[Any], None, type, _SupportsDType, str,
+        # Union[Tuple[Any, int], Tuple[Any, Union[int, Sequence[int]]], List[Any],
+        # _DTypeDict, Tuple[Any, Any]]]"
+        result = np.asarray(scalars, dtype=dtype)  # type: ignore[arg-type]
+        if (
+            result.ndim > 1
+            and not hasattr(scalars, "dtype")
+            and (dtype is None or dtype == object)
+        ):
+            # e.g. list-of-tuples
+            result = construct_1d_object_array_from_listlike(scalars)
+
+        if copy and result is scalars:
+            result = result.copy()
+        return cls(result)
+
+    def _from_backing_data(self, arr: np.ndarray) -> NumpyExtensionArray:
+        return type(self)(arr)
+
+    # ------------------------------------------------------------------------
+    # Data
+
+    @property
+    def dtype(self) -> NumpyEADtype:
+        return self._dtype
+
+    # ------------------------------------------------------------------------
+    # NumPy Array Interface
+
+    def __array__(
+        self, dtype: NpDtype | None = None, copy: bool | None = None
+    ) -> np.ndarray:
+        return np.asarray(self._ndarray, dtype=dtype)
+
+    def __array_ufunc__(self, ufunc: np.ufunc, method: str, *inputs, **kwargs):
+        # Lightly modified version of
+        # https://numpy.org/doc/stable/reference/generated/numpy.lib.mixins.NDArrayOperatorsMixin.html
+        # The primary modification is not boxing scalar return values
+        # in NumpyExtensionArray, since pandas' ExtensionArrays are 1-d.
+        out = kwargs.get("out", ())
+
+        result = arraylike.maybe_dispatch_ufunc_to_dunder_op(
+            self, ufunc, method, *inputs, **kwargs
+        )
+        if result is not NotImplemented:
+            return result
+
+        if "out" in kwargs:
+            # e.g. test_ufunc_unary
+            return arraylike.dispatch_ufunc_with_out(
+                self, ufunc, method, *inputs, **kwargs
+            )
+
+        if method == "reduce":
+            result = arraylike.dispatch_reduction_ufunc(
+                self, ufunc, method, *inputs, **kwargs
+            )
+            if result is not NotImplemented:
+                # e.g. tests.series.test_ufunc.TestNumpyReductions
+                return result
+
+        # Defer to the implementation of the ufunc on unwrapped values.
+        inputs = tuple(
+            x._ndarray if isinstance(x, NumpyExtensionArray) else x for x in inputs
+        )
+        if out:
+            kwargs["out"] = tuple(
+                x._ndarray if isinstance(x, NumpyExtensionArray) else x for x in out
+            )
+        result = getattr(ufunc, method)(*inputs, **kwargs)
+
+        if ufunc.nout > 1:
+            # multiple return values; re-box array-like results
+            return tuple(type(self)(x) for x in result)
+        elif method == "at":
+            # no return value
+            return None
+        elif method == "reduce":
+            if isinstance(result, np.ndarray):
+                # e.g. test_np_reduce_2d
+                return type(self)(result)
+
+            # e.g. test_np_max_nested_tuples
+            return result
+        else:
+            # one return value; re-box array-like results
+            return type(self)(result)
+
+    # ------------------------------------------------------------------------
+    # Pandas ExtensionArray Interface
+
+    def astype(self, dtype, copy: bool = True):
+        dtype = pandas_dtype(dtype)
+
+        if dtype == self.dtype:
+            if copy:
+                return self.copy()
+            return self
+
+        result = astype_array(self._ndarray, dtype=dtype, copy=copy)
+        return result
+
+    def isna(self) -> np.ndarray:
+        return isna(self._ndarray)
+
+    def _validate_scalar(self, fill_value):
+        if fill_value is None:
+            # Primarily for subclasses
+            fill_value = self.dtype.na_value
+        return fill_value
+
+    def _values_for_factorize(self) -> tuple[np.ndarray, float | None]:
+        if self.dtype.kind in "iub":
+            fv = None
+        else:
+            fv = np.nan
+        return self._ndarray, fv
+
+    # Base EA class (and all other EA classes) don't have limit_area keyword
+    # This can be removed here as well when the interpolate ffill/bfill method
+    # deprecation is enforced
+    def _pad_or_backfill(
+        self,
+        *,
+        method: FillnaOptions,
+        limit: int | None = None,
+        limit_area: Literal["inside", "outside"] | None = None,
+        copy: bool = True,
+    ) -> Self:
+        """
+        ffill or bfill along axis=0.
+        """
+        if copy:
+            out_data = self._ndarray.copy()
+        else:
+            out_data = self._ndarray
+
+        meth = missing.clean_fill_method(method)
+        missing.pad_or_backfill_inplace(
+            out_data.T,
+            method=meth,
+            axis=0,
+            limit=limit,
+            limit_area=limit_area,
+        )
+
+        if not copy:
+            return self
+        return type(self)._simple_new(out_data, dtype=self.dtype)
+
+    def interpolate(
+        self,
+        *,
+        method: InterpolateOptions,
+        axis: int,
+        index: Index,
+        limit,
+        limit_direction,
+        limit_area,
+        copy: bool,
+        **kwargs,
+    ) -> Self:
+        """
+        See NDFrame.interpolate.__doc__.
+        """
+        # NB: we return type(self) even if copy=False
+        if not copy:
+            out_data = self._ndarray
+        else:
+            out_data = self._ndarray.copy()
+
+        # TODO: assert we have floating dtype?
+        missing.interpolate_2d_inplace(
+            out_data,
+            method=method,
+            axis=axis,
+            index=index,
+            limit=limit,
+            limit_direction=limit_direction,
+            limit_area=limit_area,
+            **kwargs,
+        )
+        if not copy:
+            return self
+        return type(self)._simple_new(out_data, dtype=self.dtype)
+
+    # ------------------------------------------------------------------------
+    # Reductions
+
+    def any(
+        self,
+        *,
+        axis: AxisInt | None = None,
+        out=None,
+        keepdims: bool = False,
+        skipna: bool = True,
+    ):
+        nv.validate_any((), {"out": out, "keepdims": keepdims})
+        result = nanops.nanany(self._ndarray, axis=axis, skipna=skipna)
+        return self._wrap_reduction_result(axis, result)
+
+    def all(
+        self,
+        *,
+        axis: AxisInt | None = None,
+        out=None,
+        keepdims: bool = False,
+        skipna: bool = True,
+    ):
+        nv.validate_all((), {"out": out, "keepdims": keepdims})
+        result = nanops.nanall(self._ndarray, axis=axis, skipna=skipna)
+        return self._wrap_reduction_result(axis, result)
+
+    def min(
+        self, *, axis: AxisInt | None = None, skipna: bool = True, **kwargs
+    ) -> Scalar:
+        nv.validate_min((), kwargs)
+        result = nanops.nanmin(
+            values=self._ndarray, axis=axis, mask=self.isna(), skipna=skipna
+        )
+        return self._wrap_reduction_result(axis, result)
+
+    def max(
+        self, *, axis: AxisInt | None = None, skipna: bool = True, **kwargs
+    ) -> Scalar:
+        nv.validate_max((), kwargs)
+        result = nanops.nanmax(
+            values=self._ndarray, axis=axis, mask=self.isna(), skipna=skipna
+        )
+        return self._wrap_reduction_result(axis, result)
+
+    def sum(
+        self,
+        *,
+        axis: AxisInt | None = None,
+        skipna: bool = True,
+        min_count: int = 0,
+        **kwargs,
+    ) -> Scalar:
+        nv.validate_sum((), kwargs)
+        result = nanops.nansum(
+            self._ndarray, axis=axis, skipna=skipna, min_count=min_count
+        )
+        return self._wrap_reduction_result(axis, result)
+
+    def prod(
+        self,
+        *,
+        axis: AxisInt | None = None,
+        skipna: bool = True,
+        min_count: int = 0,
+        **kwargs,
+    ) -> Scalar:
+        nv.validate_prod((), kwargs)
+        result = nanops.nanprod(
+            self._ndarray, axis=axis, skipna=skipna, min_count=min_count
+        )
+        return self._wrap_reduction_result(axis, result)
+
+    def mean(
+        self,
+        *,
+        axis: AxisInt | None = None,
+        dtype: NpDtype | None = None,
+        out=None,
+        keepdims: bool = False,
+        skipna: bool = True,
+    ):
+        nv.validate_mean((), {"dtype": dtype, "out": out, "keepdims": keepdims})
+        result = nanops.nanmean(self._ndarray, axis=axis, skipna=skipna)
+        return self._wrap_reduction_result(axis, result)
+
+    def median(
+        self,
+        *,
+        axis: AxisInt | None = None,
+        out=None,
+        overwrite_input: bool = False,
+        keepdims: bool = False,
+        skipna: bool = True,
+    ):
+        nv.validate_median(
+            (), {"out": out, "overwrite_input": overwrite_input, "keepdims": keepdims}
+        )
+        result = nanops.nanmedian(self._ndarray, axis=axis, skipna=skipna)
+        return self._wrap_reduction_result(axis, result)
+
+    def std(
+        self,
+        *,
+        axis: AxisInt | None = None,
+        dtype: NpDtype | None = None,
+        out=None,
+        ddof: int = 1,
+        keepdims: bool = False,
+        skipna: bool = True,
+    ):
+        nv.validate_stat_ddof_func(
+            (), {"dtype": dtype, "out": out, "keepdims": keepdims}, fname="std"
+        )
+        result = nanops.nanstd(self._ndarray, axis=axis, skipna=skipna, ddof=ddof)
+        return self._wrap_reduction_result(axis, result)
+
+    def var(
+        self,
+        *,
+        axis: AxisInt | None = None,
+        dtype: NpDtype | None = None,
+        out=None,
+        ddof: int = 1,
+        keepdims: bool = False,
+        skipna: bool = True,
+    ):
+        nv.validate_stat_ddof_func(
+            (), {"dtype": dtype, "out": out, "keepdims": keepdims}, fname="var"
+        )
+        result = nanops.nanvar(self._ndarray, axis=axis, skipna=skipna, ddof=ddof)
+        return self._wrap_reduction_result(axis, result)
+
+    def sem(
+        self,
+        *,
+        axis: AxisInt | None = None,
+        dtype: NpDtype | None = None,
+        out=None,
+        ddof: int = 1,
+        keepdims: bool = False,
+        skipna: bool = True,
+    ):
+        nv.validate_stat_ddof_func(
+            (), {"dtype": dtype, "out": out, "keepdims": keepdims}, fname="sem"
+        )
+        result = nanops.nansem(self._ndarray, axis=axis, skipna=skipna, ddof=ddof)
+        return self._wrap_reduction_result(axis, result)
+
+    def kurt(
+        self,
+        *,
+        axis: AxisInt | None = None,
+        dtype: NpDtype | None = None,
+        out=None,
+        keepdims: bool = False,
+        skipna: bool = True,
+    ):
+        nv.validate_stat_ddof_func(
+            (), {"dtype": dtype, "out": out, "keepdims": keepdims}, fname="kurt"
+        )
+        result = nanops.nankurt(self._ndarray, axis=axis, skipna=skipna)
+        return self._wrap_reduction_result(axis, result)
+
+    def skew(
+        self,
+        *,
+        axis: AxisInt | None = None,
+        dtype: NpDtype | None = None,
+        out=None,
+        keepdims: bool = False,
+        skipna: bool = True,
+    ):
+        nv.validate_stat_ddof_func(
+            (), {"dtype": dtype, "out": out, "keepdims": keepdims}, fname="skew"
+        )
+        result = nanops.nanskew(self._ndarray, axis=axis, skipna=skipna)
+        return self._wrap_reduction_result(axis, result)
+
+    # ------------------------------------------------------------------------
+    # Additional Methods
+
+    def to_numpy(
+        self,
+        dtype: npt.DTypeLike | None = None,
+        copy: bool = False,
+        na_value: object = lib.no_default,
+    ) -> np.ndarray:
+        mask = self.isna()
+        if na_value is not lib.no_default and mask.any():
+            result = self._ndarray.copy()
+            result[mask] = na_value
+        else:
+            result = self._ndarray
+
+        result = np.asarray(result, dtype=dtype)
+
+        if copy and result is self._ndarray:
+            result = result.copy()
+
+        return result
+
+    # ------------------------------------------------------------------------
+    # Ops
+
+    def __invert__(self) -> NumpyExtensionArray:
+        return type(self)(~self._ndarray)
+
+    def __neg__(self) -> NumpyExtensionArray:
+        return type(self)(-self._ndarray)
+
+    def __pos__(self) -> NumpyExtensionArray:
+        return type(self)(+self._ndarray)
+
+    def __abs__(self) -> NumpyExtensionArray:
+        return type(self)(abs(self._ndarray))
+
+    def _cmp_method(self, other, op):
+        if isinstance(other, NumpyExtensionArray):
+            other = other._ndarray
+
+        other = ops.maybe_prepare_scalar_for_op(other, (len(self),))
+        pd_op = ops.get_array_op(op)
+        other = ensure_wrapped_if_datetimelike(other)
+        result = pd_op(self._ndarray, other)
+
+        if op is divmod or op is ops.rdivmod:
+            a, b = result
+            if isinstance(a, np.ndarray):
+                # for e.g. op vs TimedeltaArray, we may already
+                #  have an ExtensionArray, in which case we do not wrap
+                return self._wrap_ndarray_result(a), self._wrap_ndarray_result(b)
+            return a, b
+
+        if isinstance(result, np.ndarray):
+            # for e.g. multiplication vs TimedeltaArray, we may already
+            #  have an ExtensionArray, in which case we do not wrap
+            return self._wrap_ndarray_result(result)
+        return result
+
+    _arith_method = _cmp_method
+
+    def _wrap_ndarray_result(self, result: np.ndarray):
+        # If we have timedelta64[ns] result, return a TimedeltaArray instead
+        #  of a NumpyExtensionArray
+        if result.dtype.kind == "m" and is_supported_dtype(result.dtype):
+            from pandas.core.arrays import TimedeltaArray
+
+            return TimedeltaArray._simple_new(result, dtype=result.dtype)
+        return type(self)(result)
+
+    # ------------------------------------------------------------------------
+    # String methods interface
+    _str_na_value = np.nan

venv/lib/python3.10/site-packages/pandas/core/arrays/sparse/__init__.py

@@ -0,0 +1,19 @@
+from pandas.core.arrays.sparse.accessor import (
+    SparseAccessor,
+    SparseFrameAccessor,
+)
+from pandas.core.arrays.sparse.array import (
+    BlockIndex,
+    IntIndex,
+    SparseArray,
+    make_sparse_index,
+)
+
+__all__ = [
+    "BlockIndex",
+    "IntIndex",
+    "make_sparse_index",
+    "SparseAccessor",
+    "SparseArray",
+    "SparseFrameAccessor",
+]

venv/lib/python3.10/site-packages/pandas/core/arrays/sparse/accessor.py

@@ -0,0 +1,414 @@
+"""Sparse accessor"""
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+import numpy as np
+
+from pandas.compat._optional import import_optional_dependency
+
+from pandas.core.dtypes.cast import find_common_type
+from pandas.core.dtypes.dtypes import SparseDtype
+
+from pandas.core.accessor import (
+    PandasDelegate,
+    delegate_names,
+)
+from pandas.core.arrays.sparse.array import SparseArray
+
+if TYPE_CHECKING:
+    from pandas import (
+        DataFrame,
+        Series,
+    )
+
+
+class BaseAccessor:
+    _validation_msg = "Can only use the '.sparse' accessor with Sparse data."
+
+    def __init__(self, data=None) -> None:
+        self._parent = data
+        self._validate(data)
+
+    def _validate(self, data):
+        raise NotImplementedError
+
+
+@delegate_names(
+    SparseArray, ["npoints", "density", "fill_value", "sp_values"], typ="property"
+)
+class SparseAccessor(BaseAccessor, PandasDelegate):
+    """
+    Accessor for SparseSparse from other sparse matrix data types.
+
+    Examples
+    --------
+    >>> ser = pd.Series([0, 0, 2, 2, 2], dtype="Sparse[int]")
+    >>> ser.sparse.density
+    0.6
+    >>> ser.sparse.sp_values
+    array([2, 2, 2])
+    """
+
+    def _validate(self, data):
+        if not isinstance(data.dtype, SparseDtype):
+            raise AttributeError(self._validation_msg)
+
+    def _delegate_property_get(self, name: str, *args, **kwargs):
+        return getattr(self._parent.array, name)
+
+    def _delegate_method(self, name: str, *args, **kwargs):
+        if name == "from_coo":
+            return self.from_coo(*args, **kwargs)
+        elif name == "to_coo":
+            return self.to_coo(*args, **kwargs)
+        else:
+            raise ValueError
+
+    @classmethod
+    def from_coo(cls, A, dense_index: bool = False) -> Series:
+        """
+        Create a Series with sparse values from a scipy.sparse.coo_matrix.
+
+        Parameters
+        ----------
+        A : scipy.sparse.coo_matrix
+        dense_index : bool, default False
+            If False (default), the index consists of only the
+            coords of the non-null entries of the original coo_matrix.
+            If True, the index consists of the full sorted
+            (row, col) coordinates of the coo_matrix.
+
+        Returns
+        -------
+        s : Series
+            A Series with sparse values.
+
+        Examples
+        --------
+        >>> from scipy import sparse
+
+        >>> A = sparse.coo_matrix(
+        ...     ([3.0, 1.0, 2.0], ([1, 0, 0], [0, 2, 3])), shape=(3, 4)
+        ... )
+        >>> A
+        <3x4 sparse matrix of type '<class 'numpy.float64'>'
+        with 3 stored elements in COOrdinate format>
+
+        >>> A.todense()
+        matrix([[0., 0., 1., 2.],
+        [3., 0., 0., 0.],
+        [0., 0., 0., 0.]])
+
+        >>> ss = pd.Series.sparse.from_coo(A)
+        >>> ss
+        0  2    1.0
+           3    2.0
+        1  0    3.0
+        dtype: Sparse[float64, nan]
+        """
+        from pandas import Series
+        from pandas.core.arrays.sparse.scipy_sparse import coo_to_sparse_series
+
+        result = coo_to_sparse_series(A, dense_index=dense_index)
+        result = Series(result.array, index=result.index, copy=False)
+
+        return result
+
+    def to_coo(self, row_levels=(0,), column_levels=(1,), sort_labels: bool = False):
+        """
+        Create a scipy.sparse.coo_matrix from a Series with MultiIndex.
+
+        Use row_levels and column_levels to determine the row and column
+        coordinates respectively. row_levels and column_levels are the names
+        (labels) or numbers of the levels. {row_levels, column_levels} must be
+        a partition of the MultiIndex level names (or numbers).
+
+        Parameters
+        ----------
+        row_levels : tuple/list
+        column_levels : tuple/list
+        sort_labels : bool, default False
+            Sort the row and column labels before forming the sparse matrix.
+            When `row_levels` and/or `column_levels` refer to a single level,
+            set to `True` for a faster execution.
+
+        Returns
+        -------
+        y : scipy.sparse.coo_matrix
+        rows : list (row labels)
+        columns : list (column labels)
+
+        Examples
+        --------
+        >>> s = pd.Series([3.0, np.nan, 1.0, 3.0, np.nan, np.nan])
+        >>> s.index = pd.MultiIndex.from_tuples(
+        ...     [
+        ...         (1, 2, "a", 0),
+        ...         (1, 2, "a", 1),
+        ...         (1, 1, "b", 0),
+        ...         (1, 1, "b", 1),
+        ...         (2, 1, "b", 0),
+        ...         (2, 1, "b", 1)
+        ...     ],
+        ...     names=["A", "B", "C", "D"],
+        ... )
+        >>> s
+        A  B  C  D
+        1  2  a  0    3.0
+                 1    NaN
+           1  b  0    1.0
+                 1    3.0
+        2  1  b  0    NaN
+                 1    NaN
+        dtype: float64
+
+        >>> ss = s.astype("Sparse")
+        >>> ss
+        A  B  C  D
+        1  2  a  0    3.0
+                 1    NaN
+           1  b  0    1.0
+                 1    3.0
+        2  1  b  0    NaN
+                 1    NaN
+        dtype: Sparse[float64, nan]
+
+        >>> A, rows, columns = ss.sparse.to_coo(
+        ...     row_levels=["A", "B"], column_levels=["C", "D"], sort_labels=True
+        ... )
+        >>> A
+        <3x4 sparse matrix of type '<class 'numpy.float64'>'
+        with 3 stored elements in COOrdinate format>
+        >>> A.todense()
+        matrix([[0., 0., 1., 3.],
+        [3., 0., 0., 0.],
+        [0., 0., 0., 0.]])
+
+        >>> rows
+        [(1, 1), (1, 2), (2, 1)]
+        >>> columns
+        [('a', 0), ('a', 1), ('b', 0), ('b', 1)]
+        """
+        from pandas.core.arrays.sparse.scipy_sparse import sparse_series_to_coo
+
+        A, rows, columns = sparse_series_to_coo(
+            self._parent, row_levels, column_levels, sort_labels=sort_labels
+        )
+        return A, rows, columns
+
+    def to_dense(self) -> Series:
+        """
+        Convert a Series from sparse values to dense.
+
+        Returns
+        -------
+        Series:
+            A Series with the same values, stored as a dense array.
+
+        Examples
+        --------
+        >>> series = pd.Series(pd.arrays.SparseArray([0, 1, 0]))
+        >>> series
+        0    0
+        1    1
+        2    0
+        dtype: Sparse[int64, 0]
+
+        >>> series.sparse.to_dense()
+        0    0
+        1    1
+        2    0
+        dtype: int64
+        """
+        from pandas import Series
+
+        return Series(
+            self._parent.array.to_dense(),
+            index=self._parent.index,
+            name=self._parent.name,
+            copy=False,
+        )
+
+
+class SparseFrameAccessor(BaseAccessor, PandasDelegate):
+    """
+    DataFrame accessor for sparse data.
+
+    Examples
+    --------
+    >>> df = pd.DataFrame({"a": [1, 2, 0, 0],
+    ...                   "b": [3, 0, 0, 4]}, dtype="Sparse[int]")
+    >>> df.sparse.density
+    0.5
+    """
+
+    def _validate(self, data):
+        dtypes = data.dtypes
+        if not all(isinstance(t, SparseDtype) for t in dtypes):
+            raise AttributeError(self._validation_msg)
+
+    @classmethod
+    def from_spmatrix(cls, data, index=None, columns=None) -> DataFrame:
+        """
+        Create a new DataFrame from a scipy sparse matrix.
+
+        Parameters
+        ----------
+        data : scipy.sparse.spmatrix
+            Must be convertible to csc format.
+        index, columns : Index, optional
+            Row and column labels to use for the resulting DataFrame.
+            Defaults to a RangeIndex.
+
+        Returns
+        -------
+        DataFrame
+            Each column of the DataFrame is stored as a
+            :class:`arrays.SparseArray`.
+
+        Examples
+        --------
+        >>> import scipy.sparse
+        >>> mat = scipy.sparse.eye(3, dtype=float)
+        >>> pd.DataFrame.sparse.from_spmatrix(mat)
+             0    1    2
+        0  1.0    0    0
+        1    0  1.0    0
+        2    0    0  1.0
+        """
+        from pandas._libs.sparse import IntIndex
+
+        from pandas import DataFrame
+
+        data = data.tocsc()
+        index, columns = cls._prep_index(data, index, columns)
+        n_rows, n_columns = data.shape
+        # We need to make sure indices are sorted, as we create
+        # IntIndex with no input validation (i.e. check_integrity=False ).
+        # Indices may already be sorted in scipy in which case this adds
+        # a small overhead.
+        data.sort_indices()
+        indices = data.indices
+        indptr = data.indptr
+        array_data = data.data
+        dtype = SparseDtype(array_data.dtype, 0)
+        arrays = []
+        for i in range(n_columns):
+            sl = slice(indptr[i], indptr[i + 1])
+            idx = IntIndex(n_rows, indices[sl], check_integrity=False)
+            arr = SparseArray._simple_new(array_data[sl], idx, dtype)
+            arrays.append(arr)
+        return DataFrame._from_arrays(
+            arrays, columns=columns, index=index, verify_integrity=False
+        )
+
+    def to_dense(self) -> DataFrame:
+        """
+        Convert a DataFrame with sparse values to dense.
+
+        Returns
+        -------
+        DataFrame
+            A DataFrame with the same values stored as dense arrays.
+
+        Examples
+        --------
+        >>> df = pd.DataFrame({"A": pd.arrays.SparseArray([0, 1, 0])})
+        >>> df.sparse.to_dense()
+           A
+        0  0
+        1  1
+        2  0
+        """
+        from pandas import DataFrame
+
+        data = {k: v.array.to_dense() for k, v in self._parent.items()}
+        return DataFrame(data, index=self._parent.index, columns=self._parent.columns)
+
+    def to_coo(self):
+        """
+        Return the contents of the frame as a sparse SciPy COO matrix.
+
+        Returns
+        -------
+        scipy.sparse.spmatrix
+            If the caller is heterogeneous and contains booleans or objects,
+            the result will be of dtype=object. See Notes.
+
+        Notes
+        -----
+        The dtype will be the lowest-common-denominator type (implicit
+        upcasting); that is to say if the dtypes (even of numeric types)
+        are mixed, the one that accommodates all will be chosen.
+
+        e.g. If the dtypes are float16 and float32, dtype will be upcast to
+        float32. By numpy.find_common_type convention, mixing int64 and
+        and uint64 will result in a float64 dtype.
+
+        Examples
+        --------
+        >>> df = pd.DataFrame({"A": pd.arrays.SparseArray([0, 1, 0, 1])})
+        >>> df.sparse.to_coo()
+        <4x1 sparse matrix of type '<class 'numpy.int64'>'
+                with 2 stored elements in COOrdinate format>
+        """
+        import_optional_dependency("scipy")
+        from scipy.sparse import coo_matrix
+
+        dtype = find_common_type(self._parent.dtypes.to_list())
+        if isinstance(dtype, SparseDtype):
+            dtype = dtype.subtype
+
+        cols, rows, data = [], [], []
+        for col, (_, ser) in enumerate(self._parent.items()):
+            sp_arr = ser.array
+            if sp_arr.fill_value != 0:
+                raise ValueError("fill value must be 0 when converting to COO matrix")
+
+            row = sp_arr.sp_index.indices
+            cols.append(np.repeat(col, len(row)))
+            rows.append(row)
+            data.append(sp_arr.sp_values.astype(dtype, copy=False))
+
+        cols = np.concatenate(cols)
+        rows = np.concatenate(rows)
+        data = np.concatenate(data)
+        return coo_matrix((data, (rows, cols)), shape=self._parent.shape)
+
+    @property
+    def density(self) -> float:
+        """
+        Ratio of non-sparse points to total (dense) data points.
+
+        Examples
+        --------
+        >>> df = pd.DataFrame({"A": pd.arrays.SparseArray([0, 1, 0, 1])})
+        >>> df.sparse.density
+        0.5
+        """
+        tmp = np.mean([column.array.density for _, column in self._parent.items()])
+        return tmp
+
+    @staticmethod
+    def _prep_index(data, index, columns):
+        from pandas.core.indexes.api import (
+            default_index,
+            ensure_index,
+        )
+
+        N, K = data.shape
+        if index is None:
+            index = default_index(N)
+        else:
+            index = ensure_index(index)
+        if columns is None:
+            columns = default_index(K)
+        else:
+            columns = ensure_index(columns)
+
+        if len(columns) != K:
+            raise ValueError(f"Column length mismatch: {len(columns)} vs. {K}")
+        if len(index) != N:
+            raise ValueError(f"Index length mismatch: {len(index)} vs. {N}")
+        return index, columns

venv/lib/python3.10/site-packages/pandas/core/arrays/sparse/array.py

@@ -0,0 +1,1929 @@
+"""
+SparseArray data structure
+"""
+from __future__ import annotations
+
+from collections import abc
+import numbers
+import operator
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    Callable,
+    Literal,
+    cast,
+    overload,
+)
+import warnings
+
+import numpy as np
+
+from pandas._libs import lib
+import pandas._libs.sparse as splib
+from pandas._libs.sparse import (
+    BlockIndex,
+    IntIndex,
+    SparseIndex,
+)
+from pandas._libs.tslibs import NaT
+from pandas.compat.numpy import function as nv
+from pandas.errors import PerformanceWarning
+from pandas.util._decorators import doc
+from pandas.util._exceptions import find_stack_level
+from pandas.util._validators import (
+    validate_bool_kwarg,
+    validate_insert_loc,
+)
+
+from pandas.core.dtypes.astype import astype_array
+from pandas.core.dtypes.cast import (
+    construct_1d_arraylike_from_scalar,
+    find_common_type,
+    maybe_box_datetimelike,
+)
+from pandas.core.dtypes.common import (
+    is_bool_dtype,
+    is_integer,
+    is_list_like,
+    is_object_dtype,
+    is_scalar,
+    is_string_dtype,
+    pandas_dtype,
+)
+from pandas.core.dtypes.dtypes import (
+    DatetimeTZDtype,
+    SparseDtype,
+)
+from pandas.core.dtypes.generic import (
+    ABCIndex,
+    ABCSeries,
+)
+from pandas.core.dtypes.missing import (
+    isna,
+    na_value_for_dtype,
+    notna,
+)
+
+from pandas.core import arraylike
+import pandas.core.algorithms as algos
+from pandas.core.arraylike import OpsMixin
+from pandas.core.arrays import ExtensionArray
+from pandas.core.base import PandasObject
+import pandas.core.common as com
+from pandas.core.construction import (
+    ensure_wrapped_if_datetimelike,
+    extract_array,
+    sanitize_array,
+)
+from pandas.core.indexers import (
+    check_array_indexer,
+    unpack_tuple_and_ellipses,
+)
+from pandas.core.nanops import check_below_min_count
+
+from pandas.io.formats import printing
+
+# See https://github.com/python/typing/issues/684
+if TYPE_CHECKING:
+    from collections.abc import Sequence
+    from enum import Enum
+
+    class ellipsis(Enum):
+        Ellipsis = "..."
+
+    Ellipsis = ellipsis.Ellipsis
+
+    from scipy.sparse import spmatrix
+
+    from pandas._typing import (
+        FillnaOptions,
+        NumpySorter,
+    )
+
+    SparseIndexKind = Literal["integer", "block"]
+
+    from pandas._typing import (
+        ArrayLike,
+        AstypeArg,
+        Axis,
+        AxisInt,
+        Dtype,
+        NpDtype,
+        PositionalIndexer,
+        Scalar,
+        ScalarIndexer,
+        Self,
+        SequenceIndexer,
+        npt,
+    )
+
+    from pandas import Series
+
+else:
+    ellipsis = type(Ellipsis)
+
+
+# ----------------------------------------------------------------------------
+# Array
+
+_sparray_doc_kwargs = {"klass": "SparseArray"}
+
+
+def _get_fill(arr: SparseArray) -> np.ndarray:
+    """
+    Create a 0-dim ndarray containing the fill value
+
+    Parameters
+    ----------
+    arr : SparseArray
+
+    Returns
+    -------
+    fill_value : ndarray
+        0-dim ndarray with just the fill value.
+
+    Notes
+    -----
+    coerce fill_value to arr dtype if possible
+    int64 SparseArray can have NaN as fill_value if there is no missing
+    """
+    try:
+        return np.asarray(arr.fill_value, dtype=arr.dtype.subtype)
+    except ValueError:
+        return np.asarray(arr.fill_value)
+
+
+def _sparse_array_op(
+    left: SparseArray, right: SparseArray, op: Callable, name: str
+) -> SparseArray:
+    """
+    Perform a binary operation between two arrays.
+
+    Parameters
+    ----------
+    left : Union[SparseArray, ndarray]
+    right : Union[SparseArray, ndarray]
+    op : Callable
+        The binary operation to perform
+    name str
+        Name of the callable.
+
+    Returns
+    -------
+    SparseArray
+    """
+    if name.startswith("__"):
+        # For lookups in _libs.sparse we need non-dunder op name
+        name = name[2:-2]
+
+    # dtype used to find corresponding sparse method
+    ltype = left.dtype.subtype
+    rtype = right.dtype.subtype
+
+    if ltype != rtype:
+        subtype = find_common_type([ltype, rtype])
+        ltype = SparseDtype(subtype, left.fill_value)
+        rtype = SparseDtype(subtype, right.fill_value)
+
+        left = left.astype(ltype, copy=False)
+        right = right.astype(rtype, copy=False)
+        dtype = ltype.subtype
+    else:
+        dtype = ltype
+
+    # dtype the result must have
+    result_dtype = None
+
+    if left.sp_index.ngaps == 0 or right.sp_index.ngaps == 0:
+        with np.errstate(all="ignore"):
+            result = op(left.to_dense(), right.to_dense())
+            fill = op(_get_fill(left), _get_fill(right))
+
+        if left.sp_index.ngaps == 0:
+            index = left.sp_index
+        else:
+            index = right.sp_index
+    elif left.sp_index.equals(right.sp_index):
+        with np.errstate(all="ignore"):
+            result = op(left.sp_values, right.sp_values)
+            fill = op(_get_fill(left), _get_fill(right))
+        index = left.sp_index
+    else:
+        if name[0] == "r":
+            left, right = right, left
+            name = name[1:]
+
+        if name in ("and", "or", "xor") and dtype == "bool":
+            opname = f"sparse_{name}_uint8"
+            # to make template simple, cast here
+            left_sp_values = left.sp_values.view(np.uint8)
+            right_sp_values = right.sp_values.view(np.uint8)
+            result_dtype = bool
+        else:
+            opname = f"sparse_{name}_{dtype}"
+            left_sp_values = left.sp_values
+            right_sp_values = right.sp_values
+
+        if (
+            name in ["floordiv", "mod"]
+            and (right == 0).any()
+            and left.dtype.kind in "iu"
+        ):
+            # Match the non-Sparse Series behavior
+            opname = f"sparse_{name}_float64"
+            left_sp_values = left_sp_values.astype("float64")
+            right_sp_values = right_sp_values.astype("float64")
+
+        sparse_op = getattr(splib, opname)
+
+        with np.errstate(all="ignore"):
+            result, index, fill = sparse_op(
+                left_sp_values,
+                left.sp_index,
+                left.fill_value,
+                right_sp_values,
+                right.sp_index,
+                right.fill_value,
+            )
+
+    if name == "divmod":
+        # result is a 2-tuple
+        # error: Incompatible return value type (got "Tuple[SparseArray,
+        # SparseArray]", expected "SparseArray")
+        return (  # type: ignore[return-value]
+            _wrap_result(name, result[0], index, fill[0], dtype=result_dtype),
+            _wrap_result(name, result[1], index, fill[1], dtype=result_dtype),
+        )
+
+    if result_dtype is None:
+        result_dtype = result.dtype
+
+    return _wrap_result(name, result, index, fill, dtype=result_dtype)
+
+
+def _wrap_result(
+    name: str, data, sparse_index, fill_value, dtype: Dtype | None = None
+) -> SparseArray:
+    """
+    wrap op result to have correct dtype
+    """
+    if name.startswith("__"):
+        # e.g. __eq__ --> eq
+        name = name[2:-2]
+
+    if name in ("eq", "ne", "lt", "gt", "le", "ge"):
+        dtype = bool
+
+    fill_value = lib.item_from_zerodim(fill_value)
+
+    if is_bool_dtype(dtype):
+        # fill_value may be np.bool_
+        fill_value = bool(fill_value)
+    return SparseArray(
+        data, sparse_index=sparse_index, fill_value=fill_value, dtype=dtype
+    )
+
+
+class SparseArray(OpsMixin, PandasObject, ExtensionArray):
+    """
+    An ExtensionArray for storing sparse data.
+
+    Parameters
+    ----------
+    data : array-like or scalar
+        A dense array of values to store in the SparseArray. This may contain
+        `fill_value`.
+    sparse_index : SparseIndex, optional
+    fill_value : scalar, optional
+        Elements in data that are ``fill_value`` are not stored in the
+        SparseArray. For memory savings, this should be the most common value
+        in `data`. By default, `fill_value` depends on the dtype of `data`:
+
+        =========== ==========
+        data.dtype  na_value
+        =========== ==========
+        float       ``np.nan``
+        int         ``0``
+        bool        False
+        datetime64  ``pd.NaT``
+        timedelta64 ``pd.NaT``
+        =========== ==========
+
+        The fill value is potentially specified in three ways. In order of
+        precedence, these are
+
+        1. The `fill_value` argument
+        2. ``dtype.fill_value`` if `fill_value` is None and `dtype` is
+           a ``SparseDtype``
+        3. ``data.dtype.fill_value`` if `fill_value` is None and `dtype`
+           is not a ``SparseDtype`` and `data` is a ``SparseArray``.
+
+    kind : str
+        Can be 'integer' or 'block', default is 'integer'.
+        The type of storage for sparse locations.
+
+        * 'block': Stores a `block` and `block_length` for each
+          contiguous *span* of sparse values. This is best when
+          sparse data tends to be clumped together, with large
+          regions of ``fill-value`` values between sparse values.
+        * 'integer': uses an integer to store the location of
+          each sparse value.
+
+    dtype : np.dtype or SparseDtype, optional
+        The dtype to use for the SparseArray. For numpy dtypes, this
+        determines the dtype of ``self.sp_values``. For SparseDtype,
+        this determines ``self.sp_values`` and ``self.fill_value``.
+    copy : bool, default False
+        Whether to explicitly copy the incoming `data` array.
+
+    Attributes
+    ----------
+    None
+
+    Methods
+    -------
+    None
+
+    Examples
+    --------
+    >>> from pandas.arrays import SparseArray
+    >>> arr = SparseArray([0, 0, 1, 2])
+    >>> arr
+    [0, 0, 1, 2]
+    Fill: 0
+    IntIndex
+    Indices: array([2, 3], dtype=int32)
+    """
+
+    _subtyp = "sparse_array"  # register ABCSparseArray
+    _hidden_attrs = PandasObject._hidden_attrs | frozenset([])
+    _sparse_index: SparseIndex
+    _sparse_values: np.ndarray
+    _dtype: SparseDtype
+
+    def __init__(
+        self,
+        data,
+        sparse_index=None,
+        fill_value=None,
+        kind: SparseIndexKind = "integer",
+        dtype: Dtype | None = None,
+        copy: bool = False,
+    ) -> None:
+        if fill_value is None and isinstance(dtype, SparseDtype):
+            fill_value = dtype.fill_value
+
+        if isinstance(data, type(self)):
+            # disable normal inference on dtype, sparse_index, & fill_value
+            if sparse_index is None:
+                sparse_index = data.sp_index
+            if fill_value is None:
+                fill_value = data.fill_value
+            if dtype is None:
+                dtype = data.dtype
+            # TODO: make kind=None, and use data.kind?
+            data = data.sp_values
+
+        # Handle use-provided dtype
+        if isinstance(dtype, str):
+            # Two options: dtype='int', regular numpy dtype
+            # or dtype='Sparse[int]', a sparse dtype
+            try:
+                dtype = SparseDtype.construct_from_string(dtype)
+            except TypeError:
+                dtype = pandas_dtype(dtype)
+
+        if isinstance(dtype, SparseDtype):
+            if fill_value is None:
+                fill_value = dtype.fill_value
+            dtype = dtype.subtype
+
+        if is_scalar(data):
+            warnings.warn(
+                f"Constructing {type(self).__name__} with scalar data is deprecated "
+                "and will raise in a future version. Pass a sequence instead.",
+                FutureWarning,
+                stacklevel=find_stack_level(),
+            )
+            if sparse_index is None:
+                npoints = 1
+            else:
+                npoints = sparse_index.length
+
+            data = construct_1d_arraylike_from_scalar(data, npoints, dtype=None)
+            dtype = data.dtype
+
+        if dtype is not None:
+            dtype = pandas_dtype(dtype)
+
+        # TODO: disentangle the fill_value dtype inference from
+        # dtype inference
+        if data is None:
+            # TODO: What should the empty dtype be? Object or float?
+
+            # error: Argument "dtype" to "array" has incompatible type
+            # "Union[ExtensionDtype, dtype[Any], None]"; expected "Union[dtype[Any],
+            # None, type, _SupportsDType, str, Union[Tuple[Any, int], Tuple[Any,
+            # Union[int, Sequence[int]]], List[Any], _DTypeDict, Tuple[Any, Any]]]"
+            data = np.array([], dtype=dtype)  # type: ignore[arg-type]
+
+        try:
+            data = sanitize_array(data, index=None)
+        except ValueError:
+            # NumPy may raise a ValueError on data like [1, []]
+            # we retry with object dtype here.
+            if dtype is None:
+                dtype = np.dtype(object)
+                data = np.atleast_1d(np.asarray(data, dtype=dtype))
+            else:
+                raise
+
+        if copy:
+            # TODO: avoid double copy when dtype forces cast.
+            data = data.copy()
+
+        if fill_value is None:
+            fill_value_dtype = data.dtype if dtype is None else dtype
+            if fill_value_dtype is None:
+                fill_value = np.nan
+            else:
+                fill_value = na_value_for_dtype(fill_value_dtype)
+
+        if isinstance(data, type(self)) and sparse_index is None:
+            sparse_index = data._sparse_index
+            # error: Argument "dtype" to "asarray" has incompatible type
+            # "Union[ExtensionDtype, dtype[Any], None]"; expected "None"
+            sparse_values = np.asarray(
+                data.sp_values, dtype=dtype  # type: ignore[arg-type]
+            )
+        elif sparse_index is None:
+            data = extract_array(data, extract_numpy=True)
+            if not isinstance(data, np.ndarray):
+                # EA
+                if isinstance(data.dtype, DatetimeTZDtype):
+                    warnings.warn(
+                        f"Creating SparseArray from {data.dtype} data "
+                        "loses timezone information. Cast to object before "
+                        "sparse to retain timezone information.",
+                        UserWarning,
+                        stacklevel=find_stack_level(),
+                    )
+                    data = np.asarray(data, dtype="datetime64[ns]")
+                    if fill_value is NaT:
+                        fill_value = np.datetime64("NaT", "ns")
+                data = np.asarray(data)
+            sparse_values, sparse_index, fill_value = _make_sparse(
+                # error: Argument "dtype" to "_make_sparse" has incompatible type
+                # "Union[ExtensionDtype, dtype[Any], None]"; expected
+                # "Optional[dtype[Any]]"
+                data,
+                kind=kind,
+                fill_value=fill_value,
+                dtype=dtype,  # type: ignore[arg-type]
+            )
+        else:
+            # error: Argument "dtype" to "asarray" has incompatible type
+            # "Union[ExtensionDtype, dtype[Any], None]"; expected "None"
+            sparse_values = np.asarray(data, dtype=dtype)  # type: ignore[arg-type]
+            if len(sparse_values) != sparse_index.npoints:
+                raise AssertionError(
+                    f"Non array-like type {type(sparse_values)} must "
+                    "have the same length as the index"
+                )
+        self._sparse_index = sparse_index
+        self._sparse_values = sparse_values
+        self._dtype = SparseDtype(sparse_values.dtype, fill_value)
+
+    @classmethod
+    def _simple_new(
+        cls,
+        sparse_array: np.ndarray,
+        sparse_index: SparseIndex,
+        dtype: SparseDtype,
+    ) -> Self:
+        new = object.__new__(cls)
+        new._sparse_index = sparse_index
+        new._sparse_values = sparse_array
+        new._dtype = dtype
+        return new
+
+    @classmethod
+    def from_spmatrix(cls, data: spmatrix) -> Self:
+        """
+        Create a SparseArray from a scipy.sparse matrix.
+
+        Parameters
+        ----------
+        data : scipy.sparse.sp_matrix
+            This should be a SciPy sparse matrix where the size
+            of the second dimension is 1. In other words, a
+            sparse matrix with a single column.
+
+        Returns
+        -------
+        SparseArray
+
+        Examples
+        --------
+        >>> import scipy.sparse
+        >>> mat = scipy.sparse.coo_matrix((4, 1))
+        >>> pd.arrays.SparseArray.from_spmatrix(mat)
+        [0.0, 0.0, 0.0, 0.0]
+        Fill: 0.0
+        IntIndex
+        Indices: array([], dtype=int32)
+        """
+        length, ncol = data.shape
+
+        if ncol != 1:
+            raise ValueError(f"'data' must have a single column, not '{ncol}'")
+
+        # our sparse index classes require that the positions be strictly
+        # increasing. So we need to sort loc, and arr accordingly.
+        data = data.tocsc()
+        data.sort_indices()
+        arr = data.data
+        idx = data.indices
+
+        zero = np.array(0, dtype=arr.dtype).item()
+        dtype = SparseDtype(arr.dtype, zero)
+        index = IntIndex(length, idx)
+
+        return cls._simple_new(arr, index, dtype)
+
+    def __array__(
+        self, dtype: NpDtype | None = None, copy: bool | None = None
+    ) -> np.ndarray:
+        fill_value = self.fill_value
+
+        if self.sp_index.ngaps == 0:
+            # Compat for na dtype and int values.
+            return self.sp_values
+        if dtype is None:
+            # Can NumPy represent this type?
+            # If not, `np.result_type` will raise. We catch that
+            # and return object.
+            if self.sp_values.dtype.kind == "M":
+                # However, we *do* special-case the common case of
+                # a datetime64 with pandas NaT.
+                if fill_value is NaT:
+                    # Can't put pd.NaT in a datetime64[ns]
+                    fill_value = np.datetime64("NaT")
+            try:
+                dtype = np.result_type(self.sp_values.dtype, type(fill_value))
+            except TypeError:
+                dtype = object
+
+        out = np.full(self.shape, fill_value, dtype=dtype)
+        out[self.sp_index.indices] = self.sp_values
+        return out
+
+    def __setitem__(self, key, value) -> None:
+        # I suppose we could allow setting of non-fill_value elements.
+        # TODO(SparseArray.__setitem__): remove special cases in
+        # ExtensionBlock.where
+        msg = "SparseArray does not support item assignment via setitem"
+        raise TypeError(msg)
+
+    @classmethod
+    def _from_sequence(cls, scalars, *, dtype: Dtype | None = None, copy: bool = False):
+        return cls(scalars, dtype=dtype)
+
+    @classmethod
+    def _from_factorized(cls, values, original):
+        return cls(values, dtype=original.dtype)
+
+    # ------------------------------------------------------------------------
+    # Data
+    # ------------------------------------------------------------------------
+    @property
+    def sp_index(self) -> SparseIndex:
+        """
+        The SparseIndex containing the location of non- ``fill_value`` points.
+        """
+        return self._sparse_index
+
+    @property
+    def sp_values(self) -> np.ndarray:
+        """
+        An ndarray containing the non- ``fill_value`` values.
+
+        Examples
+        --------
+        >>> from pandas.arrays import SparseArray
+        >>> s = SparseArray([0, 0, 1, 0, 2], fill_value=0)
+        >>> s.sp_values
+        array([1, 2])
+        """
+        return self._sparse_values
+
+    @property
+    def dtype(self) -> SparseDtype:
+        return self._dtype
+
+    @property
+    def fill_value(self):
+        """
+        Elements in `data` that are `fill_value` are not stored.
+
+        For memory savings, this should be the most common value in the array.
+
+        Examples
+        --------
+        >>> ser = pd.Series([0, 0, 2, 2, 2], dtype="Sparse[int]")
+        >>> ser.sparse.fill_value
+        0
+        >>> spa_dtype = pd.SparseDtype(dtype=np.int32, fill_value=2)
+        >>> ser = pd.Series([0, 0, 2, 2, 2], dtype=spa_dtype)
+        >>> ser.sparse.fill_value
+        2
+        """
+        return self.dtype.fill_value
+
+    @fill_value.setter
+    def fill_value(self, value) -> None:
+        self._dtype = SparseDtype(self.dtype.subtype, value)
+
+    @property
+    def kind(self) -> SparseIndexKind:
+        """
+        The kind of sparse index for this array. One of {'integer', 'block'}.
+        """
+        if isinstance(self.sp_index, IntIndex):
+            return "integer"
+        else:
+            return "block"
+
+    @property
+    def _valid_sp_values(self) -> np.ndarray:
+        sp_vals = self.sp_values
+        mask = notna(sp_vals)
+        return sp_vals[mask]
+
+    def __len__(self) -> int:
+        return self.sp_index.length
+
+    @property
+    def _null_fill_value(self) -> bool:
+        return self._dtype._is_na_fill_value
+
+    def _fill_value_matches(self, fill_value) -> bool:
+        if self._null_fill_value:
+            return isna(fill_value)
+        else:
+            return self.fill_value == fill_value
+
+    @property
+    def nbytes(self) -> int:
+        return self.sp_values.nbytes + self.sp_index.nbytes
+
+    @property
+    def density(self) -> float:
+        """
+        The percent of non- ``fill_value`` points, as decimal.
+
+        Examples
+        --------
+        >>> from pandas.arrays import SparseArray
+        >>> s = SparseArray([0, 0, 1, 1, 1], fill_value=0)
+        >>> s.density
+        0.6
+        """
+        return self.sp_index.npoints / self.sp_index.length
+
+    @property
+    def npoints(self) -> int:
+        """
+        The number of non- ``fill_value`` points.
+
+        Examples
+        --------
+        >>> from pandas.arrays import SparseArray
+        >>> s = SparseArray([0, 0, 1, 1, 1], fill_value=0)
+        >>> s.npoints
+        3
+        """
+        return self.sp_index.npoints
+
+    # error: Return type "SparseArray" of "isna" incompatible with return type
+    # "ndarray[Any, Any] | ExtensionArraySupportsAnyAll" in supertype "ExtensionArray"
+    def isna(self) -> Self:  # type: ignore[override]
+        # If null fill value, we want SparseDtype[bool, true]
+        # to preserve the same memory usage.
+        dtype = SparseDtype(bool, self._null_fill_value)
+        if self._null_fill_value:
+            return type(self)._simple_new(isna(self.sp_values), self.sp_index, dtype)
+        mask = np.full(len(self), False, dtype=np.bool_)
+        mask[self.sp_index.indices] = isna(self.sp_values)
+        return type(self)(mask, fill_value=False, dtype=dtype)
+
+    def _pad_or_backfill(  # pylint: disable=useless-parent-delegation
+        self,
+        *,
+        method: FillnaOptions,
+        limit: int | None = None,
+        limit_area: Literal["inside", "outside"] | None = None,
+        copy: bool = True,
+    ) -> Self:
+        # TODO(3.0): We can remove this method once deprecation for fillna method
+        #  keyword is enforced.
+        return super()._pad_or_backfill(
+            method=method, limit=limit, limit_area=limit_area, copy=copy
+        )
+
+    def fillna(
+        self,
+        value=None,
+        method: FillnaOptions | None = None,
+        limit: int | None = None,
+        copy: bool = True,
+    ) -> Self:
+        """
+        Fill missing values with `value`.
+
+        Parameters
+        ----------
+        value : scalar, optional
+        method : str, optional
+
+            .. warning::
+
+               Using 'method' will result in high memory use,
+               as all `fill_value` methods will be converted to
+               an in-memory ndarray
+
+        limit : int, optional
+
+        copy: bool, default True
+            Ignored for SparseArray.
+
+        Returns
+        -------
+        SparseArray
+
+        Notes
+        -----
+        When `value` is specified, the result's ``fill_value`` depends on
+        ``self.fill_value``. The goal is to maintain low-memory use.
+
+        If ``self.fill_value`` is NA, the result dtype will be
+        ``SparseDtype(self.dtype, fill_value=value)``. This will preserve
+        amount of memory used before and after filling.
+
+        When ``self.fill_value`` is not NA, the result dtype will be
+        ``self.dtype``. Again, this preserves the amount of memory used.
+        """
+        if (method is None and value is None) or (
+            method is not None and value is not None
+        ):
+            raise ValueError("Must specify one of 'method' or 'value'.")
+
+        if method is not None:
+            return super().fillna(method=method, limit=limit)
+
+        else:
+            new_values = np.where(isna(self.sp_values), value, self.sp_values)
+
+            if self._null_fill_value:
+                # This is essentially just updating the dtype.
+                new_dtype = SparseDtype(self.dtype.subtype, fill_value=value)
+            else:
+                new_dtype = self.dtype
+
+        return self._simple_new(new_values, self._sparse_index, new_dtype)
+
+    def shift(self, periods: int = 1, fill_value=None) -> Self:
+        if not len(self) or periods == 0:
+            return self.copy()
+
+        if isna(fill_value):
+            fill_value = self.dtype.na_value
+
+        subtype = np.result_type(fill_value, self.dtype.subtype)
+
+        if subtype != self.dtype.subtype:
+            # just coerce up front
+            arr = self.astype(SparseDtype(subtype, self.fill_value))
+        else:
+            arr = self
+
+        empty = self._from_sequence(
+            [fill_value] * min(abs(periods), len(self)), dtype=arr.dtype
+        )
+
+        if periods > 0:
+            a = empty
+            b = arr[:-periods]
+        else:
+            a = arr[abs(periods) :]
+            b = empty
+        return arr._concat_same_type([a, b])
+
+    def _first_fill_value_loc(self):
+        """
+        Get the location of the first fill value.
+
+        Returns
+        -------
+        int
+        """
+        if len(self) == 0 or self.sp_index.npoints == len(self):
+            return -1
+
+        indices = self.sp_index.indices
+        if not len(indices) or indices[0] > 0:
+            return 0
+
+        # a number larger than 1 should be appended to
+        # the last in case of fill value only appears
+        # in the tail of array
+        diff = np.r_[np.diff(indices), 2]
+        return indices[(diff > 1).argmax()] + 1
+
+    @doc(ExtensionArray.duplicated)
+    def duplicated(
+        self, keep: Literal["first", "last", False] = "first"
+    ) -> npt.NDArray[np.bool_]:
+        values = np.asarray(self)
+        mask = np.asarray(self.isna())
+        return algos.duplicated(values, keep=keep, mask=mask)
+
+    def unique(self) -> Self:
+        uniques = algos.unique(self.sp_values)
+        if len(self.sp_values) != len(self):
+            fill_loc = self._first_fill_value_loc()
+            # Inorder to align the behavior of pd.unique or
+            # pd.Series.unique, we should keep the original
+            # order, here we use unique again to find the
+            # insertion place. Since the length of sp_values
+            # is not large, maybe minor performance hurt
+            # is worthwhile to the correctness.
+            insert_loc = len(algos.unique(self.sp_values[:fill_loc]))
+            uniques = np.insert(uniques, insert_loc, self.fill_value)
+        return type(self)._from_sequence(uniques, dtype=self.dtype)
+
+    def _values_for_factorize(self):
+        # Still override this for hash_pandas_object
+        return np.asarray(self), self.fill_value
+
+    def factorize(
+        self,
+        use_na_sentinel: bool = True,
+    ) -> tuple[np.ndarray, SparseArray]:
+        # Currently, ExtensionArray.factorize -> Tuple[ndarray, EA]
+        # The sparsity on this is backwards from what Sparse would want. Want
+        # ExtensionArray.factorize -> Tuple[EA, EA]
+        # Given that we have to return a dense array of codes, why bother
+        # implementing an efficient factorize?
+        codes, uniques = algos.factorize(
+            np.asarray(self), use_na_sentinel=use_na_sentinel
+        )
+        uniques_sp = SparseArray(uniques, dtype=self.dtype)
+        return codes, uniques_sp
+
+    def value_counts(self, dropna: bool = True) -> Series:
+        """
+        Returns a Series containing counts of unique values.
+
+        Parameters
+        ----------
+        dropna : bool, default True
+            Don't include counts of NaN, even if NaN is in sp_values.
+
+        Returns
+        -------
+        counts : Series
+        """
+        from pandas import (
+            Index,
+            Series,
+        )
+
+        keys, counts, _ = algos.value_counts_arraylike(self.sp_values, dropna=dropna)
+        fcounts = self.sp_index.ngaps
+        if fcounts > 0 and (not self._null_fill_value or not dropna):
+            mask = isna(keys) if self._null_fill_value else keys == self.fill_value
+            if mask.any():
+                counts[mask] += fcounts
+            else:
+                # error: Argument 1 to "insert" has incompatible type "Union[
+                # ExtensionArray,ndarray[Any, Any]]"; expected "Union[
+                # _SupportsArray[dtype[Any]], Sequence[_SupportsArray[dtype
+                # [Any]]], Sequence[Sequence[_SupportsArray[dtype[Any]]]],
+                # Sequence[Sequence[Sequence[_SupportsArray[dtype[Any]]]]], Sequence
+                # [Sequence[Sequence[Sequence[_SupportsArray[dtype[Any]]]]]]]"
+                keys = np.insert(keys, 0, self.fill_value)  # type: ignore[arg-type]
+                counts = np.insert(counts, 0, fcounts)
+
+        if not isinstance(keys, ABCIndex):
+            index = Index(keys)
+        else:
+            index = keys
+        return Series(counts, index=index, copy=False)
+
+    # --------
+    # Indexing
+    # --------
+    @overload
+    def __getitem__(self, key: ScalarIndexer) -> Any:
+        ...
+
+    @overload
+    def __getitem__(
+        self,
+        key: SequenceIndexer | tuple[int | ellipsis, ...],
+    ) -> Self:
+        ...
+
+    def __getitem__(
+        self,
+        key: PositionalIndexer | tuple[int | ellipsis, ...],
+    ) -> Self | Any:
+        if isinstance(key, tuple):
+            key = unpack_tuple_and_ellipses(key)
+            if key is Ellipsis:
+                raise ValueError("Cannot slice with Ellipsis")
+
+        if is_integer(key):
+            return self._get_val_at(key)
+        elif isinstance(key, tuple):
+            # error: Invalid index type "Tuple[Union[int, ellipsis], ...]"
+            # for "ndarray[Any, Any]"; expected type
+            # "Union[SupportsIndex, _SupportsArray[dtype[Union[bool_,
+            # integer[Any]]]], _NestedSequence[_SupportsArray[dtype[
+            # Union[bool_, integer[Any]]]]], _NestedSequence[Union[
+            # bool, int]], Tuple[Union[SupportsIndex, _SupportsArray[
+            # dtype[Union[bool_, integer[Any]]]], _NestedSequence[
+            # _SupportsArray[dtype[Union[bool_, integer[Any]]]]],
+            # _NestedSequence[Union[bool, int]]], ...]]"
+            data_slice = self.to_dense()[key]  # type: ignore[index]
+        elif isinstance(key, slice):
+            # Avoid densifying when handling contiguous slices
+            if key.step is None or key.step == 1:
+                start = 0 if key.start is None else key.start
+                if start < 0:
+                    start += len(self)
+
+                end = len(self) if key.stop is None else key.stop
+                if end < 0:
+                    end += len(self)
+
+                indices = self.sp_index.indices
+                keep_inds = np.flatnonzero((indices >= start) & (indices < end))
+                sp_vals = self.sp_values[keep_inds]
+
+                sp_index = indices[keep_inds].copy()
+
+                # If we've sliced to not include the start of the array, all our indices
+                # should be shifted. NB: here we are careful to also not shift by a
+                # negative value for a case like [0, 1][-100:] where the start index
+                # should be treated like 0
+                if start > 0:
+                    sp_index -= start
+
+                # Length of our result should match applying this slice to a range
+                # of the length of our original array
+                new_len = len(range(len(self))[key])
+                new_sp_index = make_sparse_index(new_len, sp_index, self.kind)
+                return type(self)._simple_new(sp_vals, new_sp_index, self.dtype)
+            else:
+                indices = np.arange(len(self), dtype=np.int32)[key]
+                return self.take(indices)
+
+        elif not is_list_like(key):
+            # e.g. "foo" or 2.5
+            # exception message copied from numpy
+            raise IndexError(
+                r"only integers, slices (`:`), ellipsis (`...`), numpy.newaxis "
+                r"(`None`) and integer or boolean arrays are valid indices"
+            )
+
+        else:
+            if isinstance(key, SparseArray):
+                # NOTE: If we guarantee that SparseDType(bool)
+                # has only fill_value - true, false or nan
+                # (see GH PR 44955)
+                # we can apply mask very fast:
+                if is_bool_dtype(key):
+                    if isna(key.fill_value):
+                        return self.take(key.sp_index.indices[key.sp_values])
+                    if not key.fill_value:
+                        return self.take(key.sp_index.indices)
+                    n = len(self)
+                    mask = np.full(n, True, dtype=np.bool_)
+                    mask[key.sp_index.indices] = False
+                    return self.take(np.arange(n)[mask])
+                else:
+                    key = np.asarray(key)
+
+            key = check_array_indexer(self, key)
+
+            if com.is_bool_indexer(key):
+                # mypy doesn't know we have an array here
+                key = cast(np.ndarray, key)
+                return self.take(np.arange(len(key), dtype=np.int32)[key])
+            elif hasattr(key, "__len__"):
+                return self.take(key)
+            else:
+                raise ValueError(f"Cannot slice with '{key}'")
+
+        return type(self)(data_slice, kind=self.kind)
+
+    def _get_val_at(self, loc):
+        loc = validate_insert_loc(loc, len(self))
+
+        sp_loc = self.sp_index.lookup(loc)
+        if sp_loc == -1:
+            return self.fill_value
+        else:
+            val = self.sp_values[sp_loc]
+            val = maybe_box_datetimelike(val, self.sp_values.dtype)
+            return val
+
+    def take(self, indices, *, allow_fill: bool = False, fill_value=None) -> Self:
+        if is_scalar(indices):
+            raise ValueError(f"'indices' must be an array, not a scalar '{indices}'.")
+        indices = np.asarray(indices, dtype=np.int32)
+
+        dtype = None
+        if indices.size == 0:
+            result = np.array([], dtype="object")
+            dtype = self.dtype
+        elif allow_fill:
+            result = self._take_with_fill(indices, fill_value=fill_value)
+        else:
+            return self._take_without_fill(indices)
+
+        return type(self)(
+            result, fill_value=self.fill_value, kind=self.kind, dtype=dtype
+        )
+
+    def _take_with_fill(self, indices, fill_value=None) -> np.ndarray:
+        if fill_value is None:
+            fill_value = self.dtype.na_value
+
+        if indices.min() < -1:
+            raise ValueError(
+                "Invalid value in 'indices'. Must be between -1 "
+                "and the length of the array."
+            )
+
+        if indices.max() >= len(self):
+            raise IndexError("out of bounds value in 'indices'.")
+
+        if len(self) == 0:
+            # Empty... Allow taking only if all empty
+            if (indices == -1).all():
+                dtype = np.result_type(self.sp_values, type(fill_value))
+                taken = np.empty_like(indices, dtype=dtype)
+                taken.fill(fill_value)
+                return taken
+            else:
+                raise IndexError("cannot do a non-empty take from an empty axes.")
+
+        # sp_indexer may be -1 for two reasons
+        # 1.) we took for an index of -1 (new)
+        # 2.) we took a value that was self.fill_value (old)
+        sp_indexer = self.sp_index.lookup_array(indices)
+        new_fill_indices = indices == -1
+        old_fill_indices = (sp_indexer == -1) & ~new_fill_indices
+
+        if self.sp_index.npoints == 0 and old_fill_indices.all():
+            # We've looked up all valid points on an all-sparse array.
+            taken = np.full(
+                sp_indexer.shape, fill_value=self.fill_value, dtype=self.dtype.subtype
+            )
+
+        elif self.sp_index.npoints == 0:
+            # Use the old fill_value unless we took for an index of -1
+            _dtype = np.result_type(self.dtype.subtype, type(fill_value))
+            taken = np.full(sp_indexer.shape, fill_value=fill_value, dtype=_dtype)
+            taken[old_fill_indices] = self.fill_value
+        else:
+            taken = self.sp_values.take(sp_indexer)
+
+            # Fill in two steps.
+            # Old fill values
+            # New fill values
+            # potentially coercing to a new dtype at each stage.
+
+            m0 = sp_indexer[old_fill_indices] < 0
+            m1 = sp_indexer[new_fill_indices] < 0
+
+            result_type = taken.dtype
+
+            if m0.any():
+                result_type = np.result_type(result_type, type(self.fill_value))
+                taken = taken.astype(result_type)
+                taken[old_fill_indices] = self.fill_value
+
+            if m1.any():
+                result_type = np.result_type(result_type, type(fill_value))
+                taken = taken.astype(result_type)
+                taken[new_fill_indices] = fill_value
+
+        return taken
+
+    def _take_without_fill(self, indices) -> Self:
+        to_shift = indices < 0
+
+        n = len(self)
+
+        if (indices.max() >= n) or (indices.min() < -n):
+            if n == 0:
+                raise IndexError("cannot do a non-empty take from an empty axes.")
+            raise IndexError("out of bounds value in 'indices'.")
+
+        if to_shift.any():
+            indices = indices.copy()
+            indices[to_shift] += n
+
+        sp_indexer = self.sp_index.lookup_array(indices)
+        value_mask = sp_indexer != -1
+        new_sp_values = self.sp_values[sp_indexer[value_mask]]
+
+        value_indices = np.flatnonzero(value_mask).astype(np.int32, copy=False)
+
+        new_sp_index = make_sparse_index(len(indices), value_indices, kind=self.kind)
+        return type(self)._simple_new(new_sp_values, new_sp_index, dtype=self.dtype)
+
+    def searchsorted(
+        self,
+        v: ArrayLike | object,
+        side: Literal["left", "right"] = "left",
+        sorter: NumpySorter | None = None,
+    ) -> npt.NDArray[np.intp] | np.intp:
+        msg = "searchsorted requires high memory usage."
+        warnings.warn(msg, PerformanceWarning, stacklevel=find_stack_level())
+        v = np.asarray(v)
+        return np.asarray(self, dtype=self.dtype.subtype).searchsorted(v, side, sorter)
+
+    def copy(self) -> Self:
+        values = self.sp_values.copy()
+        return self._simple_new(values, self.sp_index, self.dtype)
+
+    @classmethod
+    def _concat_same_type(cls, to_concat: Sequence[Self]) -> Self:
+        fill_value = to_concat[0].fill_value
+
+        values = []
+        length = 0
+
+        if to_concat:
+            sp_kind = to_concat[0].kind
+        else:
+            sp_kind = "integer"
+
+        sp_index: SparseIndex
+        if sp_kind == "integer":
+            indices = []
+
+            for arr in to_concat:
+                int_idx = arr.sp_index.indices.copy()
+                int_idx += length  # TODO: wraparound
+                length += arr.sp_index.length
+
+                values.append(arr.sp_values)
+                indices.append(int_idx)
+
+            data = np.concatenate(values)
+            indices_arr = np.concatenate(indices)
+            # error: Argument 2 to "IntIndex" has incompatible type
+            # "ndarray[Any, dtype[signedinteger[_32Bit]]]";
+            # expected "Sequence[int]"
+            sp_index = IntIndex(length, indices_arr)  # type: ignore[arg-type]
+
+        else:
+            # when concatenating block indices, we don't claim that you'll
+            # get an identical index as concatenating the values and then
+            # creating a new index. We don't want to spend the time trying
+            # to merge blocks across arrays in `to_concat`, so the resulting
+            # BlockIndex may have more blocks.
+            blengths = []
+            blocs = []
+
+            for arr in to_concat:
+                block_idx = arr.sp_index.to_block_index()
+
+                values.append(arr.sp_values)
+                blocs.append(block_idx.blocs.copy() + length)
+                blengths.append(block_idx.blengths)
+                length += arr.sp_index.length
+
+            data = np.concatenate(values)
+            blocs_arr = np.concatenate(blocs)
+            blengths_arr = np.concatenate(blengths)
+
+            sp_index = BlockIndex(length, blocs_arr, blengths_arr)
+
+        return cls(data, sparse_index=sp_index, fill_value=fill_value)
+
+    def astype(self, dtype: AstypeArg | None = None, copy: bool = True):
+        """
+        Change the dtype of a SparseArray.
+
+        The output will always be a SparseArray. To convert to a dense
+        ndarray with a certain dtype, use :meth:`numpy.asarray`.
+
+        Parameters
+        ----------
+        dtype : np.dtype or ExtensionDtype
+            For SparseDtype, this changes the dtype of
+            ``self.sp_values`` and the ``self.fill_value``.
+
+            For other dtypes, this only changes the dtype of
+            ``self.sp_values``.
+
+        copy : bool, default True
+            Whether to ensure a copy is made, even if not necessary.
+
+        Returns
+        -------
+        SparseArray
+
+        Examples
+        --------
+        >>> arr = pd.arrays.SparseArray([0, 0, 1, 2])
+        >>> arr
+        [0, 0, 1, 2]
+        Fill: 0
+        IntIndex
+        Indices: array([2, 3], dtype=int32)
+
+        >>> arr.astype(SparseDtype(np.dtype('int32')))
+        [0, 0, 1, 2]
+        Fill: 0
+        IntIndex
+        Indices: array([2, 3], dtype=int32)
+
+        Using a NumPy dtype with a different kind (e.g. float) will coerce
+        just ``self.sp_values``.
+
+        >>> arr.astype(SparseDtype(np.dtype('float64')))
+        ... # doctest: +NORMALIZE_WHITESPACE
+        [nan, nan, 1.0, 2.0]
+        Fill: nan
+        IntIndex
+        Indices: array([2, 3], dtype=int32)
+
+        Using a SparseDtype, you can also change the fill value as well.
+
+        >>> arr.astype(SparseDtype("float64", fill_value=0.0))
+        ... # doctest: +NORMALIZE_WHITESPACE
+        [0.0, 0.0, 1.0, 2.0]
+        Fill: 0.0
+        IntIndex
+        Indices: array([2, 3], dtype=int32)
+        """
+        if dtype == self._dtype:
+            if not copy:
+                return self
+            else:
+                return self.copy()
+
+        future_dtype = pandas_dtype(dtype)
+        if not isinstance(future_dtype, SparseDtype):
+            # GH#34457
+            values = np.asarray(self)
+            values = ensure_wrapped_if_datetimelike(values)
+            return astype_array(values, dtype=future_dtype, copy=False)
+
+        dtype = self.dtype.update_dtype(dtype)
+        subtype = pandas_dtype(dtype._subtype_with_str)
+        subtype = cast(np.dtype, subtype)  # ensured by update_dtype
+        values = ensure_wrapped_if_datetimelike(self.sp_values)
+        sp_values = astype_array(values, subtype, copy=copy)
+        sp_values = np.asarray(sp_values)
+
+        return self._simple_new(sp_values, self.sp_index, dtype)
+
+    def map(self, mapper, na_action=None) -> Self:
+        """
+        Map categories using an input mapping or function.
+
+        Parameters
+        ----------
+        mapper : dict, Series, callable
+            The correspondence from old values to new.
+        na_action : {None, 'ignore'}, default None
+            If 'ignore', propagate NA values, without passing them to the
+            mapping correspondence.
+
+        Returns
+        -------
+        SparseArray
+            The output array will have the same density as the input.
+            The output fill value will be the result of applying the
+            mapping to ``self.fill_value``
+
+        Examples
+        --------
+        >>> arr = pd.arrays.SparseArray([0, 1, 2])
+        >>> arr.map(lambda x: x + 10)
+        [10, 11, 12]
+        Fill: 10
+        IntIndex
+        Indices: array([1, 2], dtype=int32)
+
+        >>> arr.map({0: 10, 1: 11, 2: 12})
+        [10, 11, 12]
+        Fill: 10
+        IntIndex
+        Indices: array([1, 2], dtype=int32)
+
+        >>> arr.map(pd.Series([10, 11, 12], index=[0, 1, 2]))
+        [10, 11, 12]
+        Fill: 10
+        IntIndex
+        Indices: array([1, 2], dtype=int32)
+        """
+        is_map = isinstance(mapper, (abc.Mapping, ABCSeries))
+
+        fill_val = self.fill_value
+
+        if na_action is None or notna(fill_val):
+            fill_val = mapper.get(fill_val, fill_val) if is_map else mapper(fill_val)
+
+        def func(sp_val):
+            new_sp_val = mapper.get(sp_val, None) if is_map else mapper(sp_val)
+            # check identity and equality because nans are not equal to each other
+            if new_sp_val is fill_val or new_sp_val == fill_val:
+                msg = "fill value in the sparse values not supported"
+                raise ValueError(msg)
+            return new_sp_val
+
+        sp_values = [func(x) for x in self.sp_values]
+
+        return type(self)(sp_values, sparse_index=self.sp_index, fill_value=fill_val)
+
+    def to_dense(self) -> np.ndarray:
+        """
+        Convert SparseArray to a NumPy array.
+
+        Returns
+        -------
+        arr : NumPy array
+        """
+        return np.asarray(self, dtype=self.sp_values.dtype)
+
+    def _where(self, mask, value):
+        # NB: may not preserve dtype, e.g. result may be Sparse[float64]
+        #  while self is Sparse[int64]
+        naive_implementation = np.where(mask, self, value)
+        dtype = SparseDtype(naive_implementation.dtype, fill_value=self.fill_value)
+        result = type(self)._from_sequence(naive_implementation, dtype=dtype)
+        return result
+
+    # ------------------------------------------------------------------------
+    # IO
+    # ------------------------------------------------------------------------
+    def __setstate__(self, state) -> None:
+        """Necessary for making this object picklable"""
+        if isinstance(state, tuple):
+            # Compat for pandas < 0.24.0
+            nd_state, (fill_value, sp_index) = state
+            sparse_values = np.array([])
+            sparse_values.__setstate__(nd_state)
+
+            self._sparse_values = sparse_values
+            self._sparse_index = sp_index
+            self._dtype = SparseDtype(sparse_values.dtype, fill_value)
+        else:
+            self.__dict__.update(state)
+
+    def nonzero(self) -> tuple[npt.NDArray[np.int32]]:
+        if self.fill_value == 0:
+            return (self.sp_index.indices,)
+        else:
+            return (self.sp_index.indices[self.sp_values != 0],)
+
+    # ------------------------------------------------------------------------
+    # Reductions
+    # ------------------------------------------------------------------------
+
+    def _reduce(
+        self, name: str, *, skipna: bool = True, keepdims: bool = False, **kwargs
+    ):
+        method = getattr(self, name, None)
+
+        if method is None:
+            raise TypeError(f"cannot perform {name} with type {self.dtype}")
+
+        if skipna:
+            arr = self
+        else:
+            arr = self.dropna()
+
+        result = getattr(arr, name)(**kwargs)
+
+        if keepdims:
+            return type(self)([result], dtype=self.dtype)
+        else:
+            return result
+
+    def all(self, axis=None, *args, **kwargs):
+        """
+        Tests whether all elements evaluate True
+
+        Returns
+        -------
+        all : bool
+
+        See Also
+        --------
+        numpy.all
+        """
+        nv.validate_all(args, kwargs)
+
+        values = self.sp_values
+
+        if len(values) != len(self) and not np.all(self.fill_value):
+            return False
+
+        return values.all()
+
+    def any(self, axis: AxisInt = 0, *args, **kwargs) -> bool:
+        """
+        Tests whether at least one of elements evaluate True
+
+        Returns
+        -------
+        any : bool
+
+        See Also
+        --------
+        numpy.any
+        """
+        nv.validate_any(args, kwargs)
+
+        values = self.sp_values
+
+        if len(values) != len(self) and np.any(self.fill_value):
+            return True
+
+        return values.any().item()
+
+    def sum(
+        self,
+        axis: AxisInt = 0,
+        min_count: int = 0,
+        skipna: bool = True,
+        *args,
+        **kwargs,
+    ) -> Scalar:
+        """
+        Sum of non-NA/null values
+
+        Parameters
+        ----------
+        axis : int, default 0
+            Not Used. NumPy compatibility.
+        min_count : int, default 0
+            The required number of valid values to perform the summation. If fewer
+            than ``min_count`` valid values are present, the result will be the missing
+            value indicator for subarray type.
+        *args, **kwargs
+            Not Used. NumPy compatibility.
+
+        Returns
+        -------
+        scalar
+        """
+        nv.validate_sum(args, kwargs)
+        valid_vals = self._valid_sp_values
+        sp_sum = valid_vals.sum()
+        has_na = self.sp_index.ngaps > 0 and not self._null_fill_value
+
+        if has_na and not skipna:
+            return na_value_for_dtype(self.dtype.subtype, compat=False)
+
+        if self._null_fill_value:
+            if check_below_min_count(valid_vals.shape, None, min_count):
+                return na_value_for_dtype(self.dtype.subtype, compat=False)
+            return sp_sum
+        else:
+            nsparse = self.sp_index.ngaps
+            if check_below_min_count(valid_vals.shape, None, min_count - nsparse):
+                return na_value_for_dtype(self.dtype.subtype, compat=False)
+            return sp_sum + self.fill_value * nsparse
+
+    def cumsum(self, axis: AxisInt = 0, *args, **kwargs) -> SparseArray:
+        """
+        Cumulative sum of non-NA/null values.
+
+        When performing the cumulative summation, any non-NA/null values will
+        be skipped. The resulting SparseArray will preserve the locations of
+        NaN values, but the fill value will be `np.nan` regardless.
+
+        Parameters
+        ----------
+        axis : int or None
+            Axis over which to perform the cumulative summation. If None,
+            perform cumulative summation over flattened array.
+
+        Returns
+        -------
+        cumsum : SparseArray
+        """
+        nv.validate_cumsum(args, kwargs)
+
+        if axis is not None and axis >= self.ndim:  # Mimic ndarray behaviour.
+            raise ValueError(f"axis(={axis}) out of bounds")
+
+        if not self._null_fill_value:
+            return SparseArray(self.to_dense()).cumsum()
+
+        return SparseArray(
+            self.sp_values.cumsum(),
+            sparse_index=self.sp_index,
+            fill_value=self.fill_value,
+        )
+
+    def mean(self, axis: Axis = 0, *args, **kwargs):
+        """
+        Mean of non-NA/null values
+
+        Returns
+        -------
+        mean : float
+        """
+        nv.validate_mean(args, kwargs)
+        valid_vals = self._valid_sp_values
+        sp_sum = valid_vals.sum()
+        ct = len(valid_vals)
+
+        if self._null_fill_value:
+            return sp_sum / ct
+        else:
+            nsparse = self.sp_index.ngaps
+            return (sp_sum + self.fill_value * nsparse) / (ct + nsparse)
+
+    def max(self, *, axis: AxisInt | None = None, skipna: bool = True):
+        """
+        Max of array values, ignoring NA values if specified.
+
+        Parameters
+        ----------
+        axis : int, default 0
+            Not Used. NumPy compatibility.
+        skipna : bool, default True
+            Whether to ignore NA values.
+
+        Returns
+        -------
+        scalar
+        """
+        nv.validate_minmax_axis(axis, self.ndim)
+        return self._min_max("max", skipna=skipna)
+
+    def min(self, *, axis: AxisInt | None = None, skipna: bool = True):
+        """
+        Min of array values, ignoring NA values if specified.
+
+        Parameters
+        ----------
+        axis : int, default 0
+            Not Used. NumPy compatibility.
+        skipna : bool, default True
+            Whether to ignore NA values.
+
+        Returns
+        -------
+        scalar
+        """
+        nv.validate_minmax_axis(axis, self.ndim)
+        return self._min_max("min", skipna=skipna)
+
+    def _min_max(self, kind: Literal["min", "max"], skipna: bool) -> Scalar:
+        """
+        Min/max of non-NA/null values
+
+        Parameters
+        ----------
+        kind : {"min", "max"}
+        skipna : bool
+
+        Returns
+        -------
+        scalar
+        """
+        valid_vals = self._valid_sp_values
+        has_nonnull_fill_vals = not self._null_fill_value and self.sp_index.ngaps > 0
+
+        if len(valid_vals) > 0:
+            sp_min_max = getattr(valid_vals, kind)()
+
+            # If a non-null fill value is currently present, it might be the min/max
+            if has_nonnull_fill_vals:
+                func = max if kind == "max" else min
+                return func(sp_min_max, self.fill_value)
+            elif skipna:
+                return sp_min_max
+            elif self.sp_index.ngaps == 0:
+                # No NAs present
+                return sp_min_max
+            else:
+                return na_value_for_dtype(self.dtype.subtype, compat=False)
+        elif has_nonnull_fill_vals:
+            return self.fill_value
+        else:
+            return na_value_for_dtype(self.dtype.subtype, compat=False)
+
+    def _argmin_argmax(self, kind: Literal["argmin", "argmax"]) -> int:
+        values = self._sparse_values
+        index = self._sparse_index.indices
+        mask = np.asarray(isna(values))
+        func = np.argmax if kind == "argmax" else np.argmin
+
+        idx = np.arange(values.shape[0])
+        non_nans = values[~mask]
+        non_nan_idx = idx[~mask]
+
+        _candidate = non_nan_idx[func(non_nans)]
+        candidate = index[_candidate]
+
+        if isna(self.fill_value):
+            return candidate
+        if kind == "argmin" and self[candidate] < self.fill_value:
+            return candidate
+        if kind == "argmax" and self[candidate] > self.fill_value:
+            return candidate
+        _loc = self._first_fill_value_loc()
+        if _loc == -1:
+            # fill_value doesn't exist
+            return candidate
+        else:
+            return _loc
+
+    def argmax(self, skipna: bool = True) -> int:
+        validate_bool_kwarg(skipna, "skipna")
+        if not skipna and self._hasna:
+            raise NotImplementedError
+        return self._argmin_argmax("argmax")
+
+    def argmin(self, skipna: bool = True) -> int:
+        validate_bool_kwarg(skipna, "skipna")
+        if not skipna and self._hasna:
+            raise NotImplementedError
+        return self._argmin_argmax("argmin")
+
+    # ------------------------------------------------------------------------
+    # Ufuncs
+    # ------------------------------------------------------------------------
+
+    _HANDLED_TYPES = (np.ndarray, numbers.Number)
+
+    def __array_ufunc__(self, ufunc: np.ufunc, method: str, *inputs, **kwargs):
+        out = kwargs.get("out", ())
+
+        for x in inputs + out:
+            if not isinstance(x, self._HANDLED_TYPES + (SparseArray,)):
+                return NotImplemented
+
+        # for binary ops, use our custom dunder methods
+        result = arraylike.maybe_dispatch_ufunc_to_dunder_op(
+            self, ufunc, method, *inputs, **kwargs
+        )
+        if result is not NotImplemented:
+            return result
+
+        if "out" in kwargs:
+            # e.g. tests.arrays.sparse.test_arithmetics.test_ndarray_inplace
+            res = arraylike.dispatch_ufunc_with_out(
+                self, ufunc, method, *inputs, **kwargs
+            )
+            return res
+
+        if method == "reduce":
+            result = arraylike.dispatch_reduction_ufunc(
+                self, ufunc, method, *inputs, **kwargs
+            )
+            if result is not NotImplemented:
+                # e.g. tests.series.test_ufunc.TestNumpyReductions
+                return result
+
+        if len(inputs) == 1:
+            # No alignment necessary.
+            sp_values = getattr(ufunc, method)(self.sp_values, **kwargs)
+            fill_value = getattr(ufunc, method)(self.fill_value, **kwargs)
+
+            if ufunc.nout > 1:
+                # multiple outputs. e.g. modf
+                arrays = tuple(
+                    self._simple_new(
+                        sp_value, self.sp_index, SparseDtype(sp_value.dtype, fv)
+                    )
+                    for sp_value, fv in zip(sp_values, fill_value)
+                )
+                return arrays
+            elif method == "reduce":
+                # e.g. reductions
+                return sp_values
+
+            return self._simple_new(
+                sp_values, self.sp_index, SparseDtype(sp_values.dtype, fill_value)
+            )
+
+        new_inputs = tuple(np.asarray(x) for x in inputs)
+        result = getattr(ufunc, method)(*new_inputs, **kwargs)
+        if out:
+            if len(out) == 1:
+                out = out[0]
+            return out
+
+        if ufunc.nout > 1:
+            return tuple(type(self)(x) for x in result)
+        elif method == "at":
+            # no return value
+            return None
+        else:
+            return type(self)(result)
+
+    # ------------------------------------------------------------------------
+    # Ops
+    # ------------------------------------------------------------------------
+
+    def _arith_method(self, other, op):
+        op_name = op.__name__
+
+        if isinstance(other, SparseArray):
+            return _sparse_array_op(self, other, op, op_name)
+
+        elif is_scalar(other):
+            with np.errstate(all="ignore"):
+                fill = op(_get_fill(self), np.asarray(other))
+                result = op(self.sp_values, other)
+
+            if op_name == "divmod":
+                left, right = result
+                lfill, rfill = fill
+                return (
+                    _wrap_result(op_name, left, self.sp_index, lfill),
+                    _wrap_result(op_name, right, self.sp_index, rfill),
+                )
+
+            return _wrap_result(op_name, result, self.sp_index, fill)
+
+        else:
+            other = np.asarray(other)
+            with np.errstate(all="ignore"):
+                if len(self) != len(other):
+                    raise AssertionError(
+                        f"length mismatch: {len(self)} vs. {len(other)}"
+                    )
+                if not isinstance(other, SparseArray):
+                    dtype = getattr(other, "dtype", None)
+                    other = SparseArray(other, fill_value=self.fill_value, dtype=dtype)
+                return _sparse_array_op(self, other, op, op_name)
+
+    def _cmp_method(self, other, op) -> SparseArray:
+        if not is_scalar(other) and not isinstance(other, type(self)):
+            # convert list-like to ndarray
+            other = np.asarray(other)
+
+        if isinstance(other, np.ndarray):
+            # TODO: make this more flexible than just ndarray...
+            other = SparseArray(other, fill_value=self.fill_value)
+
+        if isinstance(other, SparseArray):
+            if len(self) != len(other):
+                raise ValueError(
+                    f"operands have mismatched length {len(self)} and {len(other)}"
+                )
+
+            op_name = op.__name__.strip("_")
+            return _sparse_array_op(self, other, op, op_name)
+        else:
+            # scalar
+            fill_value = op(self.fill_value, other)
+            result = np.full(len(self), fill_value, dtype=np.bool_)
+            result[self.sp_index.indices] = op(self.sp_values, other)
+
+            return type(self)(
+                result,
+                fill_value=fill_value,
+                dtype=np.bool_,
+            )
+
+    _logical_method = _cmp_method
+
+    def _unary_method(self, op) -> SparseArray:
+        fill_value = op(np.array(self.fill_value)).item()
+        dtype = SparseDtype(self.dtype.subtype, fill_value)
+        # NOTE: if fill_value doesn't change
+        # we just have to apply op to sp_values
+        if isna(self.fill_value) or fill_value == self.fill_value:
+            values = op(self.sp_values)
+            return type(self)._simple_new(values, self.sp_index, self.dtype)
+        # In the other case we have to recalc indexes
+        return type(self)(op(self.to_dense()), dtype=dtype)
+
+    def __pos__(self) -> SparseArray:
+        return self._unary_method(operator.pos)
+
+    def __neg__(self) -> SparseArray:
+        return self._unary_method(operator.neg)
+
+    def __invert__(self) -> SparseArray:
+        return self._unary_method(operator.invert)
+
+    def __abs__(self) -> SparseArray:
+        return self._unary_method(operator.abs)
+
+    # ----------
+    # Formatting
+    # -----------
+    def __repr__(self) -> str:
+        pp_str = printing.pprint_thing(self)
+        pp_fill = printing.pprint_thing(self.fill_value)
+        pp_index = printing.pprint_thing(self.sp_index)
+        return f"{pp_str}\nFill: {pp_fill}\n{pp_index}"
+
+    def _formatter(self, boxed: bool = False):
+        # Defer to the formatter from the GenericArrayFormatter calling us.
+        # This will infer the correct formatter from the dtype of the values.
+        return None
+
+
+def _make_sparse(
+    arr: np.ndarray,
+    kind: SparseIndexKind = "block",
+    fill_value=None,
+    dtype: np.dtype | None = None,
+):
+    """
+    Convert ndarray to sparse format
+
+    Parameters
+    ----------
+    arr : ndarray
+    kind : {'block', 'integer'}
+    fill_value : NaN or another value
+    dtype : np.dtype, optional
+    copy : bool, default False
+
+    Returns
+    -------
+    (sparse_values, index, fill_value) : (ndarray, SparseIndex, Scalar)
+    """
+    assert isinstance(arr, np.ndarray)
+
+    if arr.ndim > 1:
+        raise TypeError("expected dimension <= 1 data")
+
+    if fill_value is None:
+        fill_value = na_value_for_dtype(arr.dtype)
+
+    if isna(fill_value):
+        mask = notna(arr)
+    else:
+        # cast to object comparison to be safe
+        if is_string_dtype(arr.dtype):
+            arr = arr.astype(object)
+
+        if is_object_dtype(arr.dtype):
+            # element-wise equality check method in numpy doesn't treat
+            # each element type, eg. 0, 0.0, and False are treated as
+            # same. So we have to check the both of its type and value.
+            mask = splib.make_mask_object_ndarray(arr, fill_value)
+        else:
+            mask = arr != fill_value
+
+    length = len(arr)
+    if length != len(mask):
+        # the arr is a SparseArray
+        indices = mask.sp_index.indices
+    else:
+        indices = mask.nonzero()[0].astype(np.int32)
+
+    index = make_sparse_index(length, indices, kind)
+    sparsified_values = arr[mask]
+    if dtype is not None:
+        sparsified_values = ensure_wrapped_if_datetimelike(sparsified_values)
+        sparsified_values = astype_array(sparsified_values, dtype=dtype)
+        sparsified_values = np.asarray(sparsified_values)
+
+    # TODO: copy
+    return sparsified_values, index, fill_value
+
+
+@overload
+def make_sparse_index(length: int, indices, kind: Literal["block"]) -> BlockIndex:
+    ...
+
+
+@overload
+def make_sparse_index(length: int, indices, kind: Literal["integer"]) -> IntIndex:
+    ...
+
+
+def make_sparse_index(length: int, indices, kind: SparseIndexKind) -> SparseIndex:
+    index: SparseIndex
+    if kind == "block":
+        locs, lens = splib.get_blocks(indices)
+        index = BlockIndex(length, locs, lens)
+    elif kind == "integer":
+        index = IntIndex(length, indices)
+    else:  # pragma: no cover
+        raise ValueError("must be block or integer type")
+    return index

venv/lib/python3.10/site-packages/pandas/core/arrays/sparse/scipy_sparse.py

@@ -0,0 +1,207 @@
+"""
+Interaction with scipy.sparse matrices.
+
+Currently only includes to_coo helpers.
+"""
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+from pandas._libs import lib
+
+from pandas.core.dtypes.missing import notna
+
+from pandas.core.algorithms import factorize
+from pandas.core.indexes.api import MultiIndex
+from pandas.core.series import Series
+
+if TYPE_CHECKING:
+    from collections.abc import Iterable
+
+    import numpy as np
+    import scipy.sparse
+
+    from pandas._typing import (
+        IndexLabel,
+        npt,
+    )
+
+
+def _check_is_partition(parts: Iterable, whole: Iterable):
+    whole = set(whole)
+    parts = [set(x) for x in parts]
+    if set.intersection(*parts) != set():
+        raise ValueError("Is not a partition because intersection is not null.")
+    if set.union(*parts) != whole:
+        raise ValueError("Is not a partition because union is not the whole.")
+
+
+def _levels_to_axis(
+    ss,
+    levels: tuple[int] | list[int],
+    valid_ilocs: npt.NDArray[np.intp],
+    sort_labels: bool = False,
+) -> tuple[npt.NDArray[np.intp], list[IndexLabel]]:
+    """
+    For a MultiIndexed sparse Series `ss`, return `ax_coords` and `ax_labels`,
+    where `ax_coords` are the coordinates along one of the two axes of the
+    destination sparse matrix, and `ax_labels` are the labels from `ss`' Index
+    which correspond to these coordinates.
+
+    Parameters
+    ----------
+    ss : Series
+    levels : tuple/list
+    valid_ilocs : numpy.ndarray
+        Array of integer positions of valid values for the sparse matrix in ss.
+    sort_labels : bool, default False
+        Sort the axis labels before forming the sparse matrix. When `levels`
+        refers to a single level, set to True for a faster execution.
+
+    Returns
+    -------
+    ax_coords : numpy.ndarray (axis coordinates)
+    ax_labels : list (axis labels)
+    """
+    # Since the labels are sorted in `Index.levels`, when we wish to sort and
+    # there is only one level of the MultiIndex for this axis, the desired
+    # output can be obtained in the following simpler, more efficient way.
+    if sort_labels and len(levels) == 1:
+        ax_coords = ss.index.codes[levels[0]][valid_ilocs]
+        ax_labels = ss.index.levels[levels[0]]
+
+    else:
+        levels_values = lib.fast_zip(
+            [ss.index.get_level_values(lvl).to_numpy() for lvl in levels]
+        )
+        codes, ax_labels = factorize(levels_values, sort=sort_labels)
+        ax_coords = codes[valid_ilocs]
+
+    ax_labels = ax_labels.tolist()
+    return ax_coords, ax_labels
+
+
+def _to_ijv(
+    ss,
+    row_levels: tuple[int] | list[int] = (0,),
+    column_levels: tuple[int] | list[int] = (1,),
+    sort_labels: bool = False,
+) -> tuple[
+    np.ndarray,
+    npt.NDArray[np.intp],
+    npt.NDArray[np.intp],
+    list[IndexLabel],
+    list[IndexLabel],
+]:
+    """
+    For an arbitrary MultiIndexed sparse Series return (v, i, j, ilabels,
+    jlabels) where (v, (i, j)) is suitable for passing to scipy.sparse.coo
+    constructor, and ilabels and jlabels are the row and column labels
+    respectively.
+
+    Parameters
+    ----------
+    ss : Series
+    row_levels : tuple/list
+    column_levels : tuple/list
+    sort_labels : bool, default False
+        Sort the row and column labels before forming the sparse matrix.
+        When `row_levels` and/or `column_levels` refer to a single level,
+        set to `True` for a faster execution.
+
+    Returns
+    -------
+    values : numpy.ndarray
+        Valid values to populate a sparse matrix, extracted from
+        ss.
+    i_coords : numpy.ndarray (row coordinates of the values)
+    j_coords : numpy.ndarray (column coordinates of the values)
+    i_labels : list (row labels)
+    j_labels : list (column labels)
+    """
+    # index and column levels must be a partition of the index
+    _check_is_partition([row_levels, column_levels], range(ss.index.nlevels))
+    # From the sparse Series, get the integer indices and data for valid sparse
+    # entries.
+    sp_vals = ss.array.sp_values
+    na_mask = notna(sp_vals)
+    values = sp_vals[na_mask]
+    valid_ilocs = ss.array.sp_index.indices[na_mask]
+
+    i_coords, i_labels = _levels_to_axis(
+        ss, row_levels, valid_ilocs, sort_labels=sort_labels
+    )
+
+    j_coords, j_labels = _levels_to_axis(
+        ss, column_levels, valid_ilocs, sort_labels=sort_labels
+    )
+
+    return values, i_coords, j_coords, i_labels, j_labels
+
+
+def sparse_series_to_coo(
+    ss: Series,
+    row_levels: Iterable[int] = (0,),
+    column_levels: Iterable[int] = (1,),
+    sort_labels: bool = False,
+) -> tuple[scipy.sparse.coo_matrix, list[IndexLabel], list[IndexLabel]]:
+    """
+    Convert a sparse Series to a scipy.sparse.coo_matrix using index
+    levels row_levels, column_levels as the row and column
+    labels respectively. Returns the sparse_matrix, row and column labels.
+    """
+    import scipy.sparse
+
+    if ss.index.nlevels < 2:
+        raise ValueError("to_coo requires MultiIndex with nlevels >= 2.")
+    if not ss.index.is_unique:
+        raise ValueError(
+            "Duplicate index entries are not allowed in to_coo transformation."
+        )
+
+    # to keep things simple, only rely on integer indexing (not labels)
+    row_levels = [ss.index._get_level_number(x) for x in row_levels]
+    column_levels = [ss.index._get_level_number(x) for x in column_levels]
+
+    v, i, j, rows, columns = _to_ijv(
+        ss, row_levels=row_levels, column_levels=column_levels, sort_labels=sort_labels
+    )
+    sparse_matrix = scipy.sparse.coo_matrix(
+        (v, (i, j)), shape=(len(rows), len(columns))
+    )
+    return sparse_matrix, rows, columns
+
+
+def coo_to_sparse_series(
+    A: scipy.sparse.coo_matrix, dense_index: bool = False
+) -> Series:
+    """
+    Convert a scipy.sparse.coo_matrix to a Series with type sparse.
+
+    Parameters
+    ----------
+    A : scipy.sparse.coo_matrix
+    dense_index : bool, default False
+
+    Returns
+    -------
+    Series
+
+    Raises
+    ------
+    TypeError if A is not a coo_matrix
+    """
+    from pandas import SparseDtype
+
+    try:
+        ser = Series(A.data, MultiIndex.from_arrays((A.row, A.col)), copy=False)
+    except AttributeError as err:
+        raise TypeError(
+            f"Expected coo_matrix. Got {type(A).__name__} instead."
+        ) from err
+    ser = ser.sort_index()
+    ser = ser.astype(SparseDtype(ser.dtype))
+    if dense_index:
+        ind = MultiIndex.from_product([A.row, A.col])
+        ser = ser.reindex(ind)
+    return ser