3RNN/Lib/site-packages/pandas/core/arrays/boolean.py
2024-05-26 19:49:15 +02:00

408 lines
12 KiB
Python

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
)