team-10/venv/Lib/site-packages/narwhals/_pandas_like/namespace.py
2025-08-02 02:00:33 +02:00

438 lines
16 KiB
Python

from __future__ import annotations
import operator
import warnings
from functools import reduce
from itertools import chain
from typing import TYPE_CHECKING, Any, Literal, Protocol, overload
from narwhals._compliant import CompliantThen, EagerNamespace, EagerWhen
from narwhals._expression_parsing import (
combine_alias_output_names,
combine_evaluate_output_names,
)
from narwhals._pandas_like.dataframe import PandasLikeDataFrame
from narwhals._pandas_like.expr import PandasLikeExpr
from narwhals._pandas_like.selectors import PandasSelectorNamespace
from narwhals._pandas_like.series import PandasLikeSeries
from narwhals._pandas_like.typing import NativeDataFrameT, NativeSeriesT
from narwhals._pandas_like.utils import is_non_nullable_boolean
if TYPE_CHECKING:
from collections.abc import Iterable, Sequence
from typing_extensions import TypeAlias
from narwhals._compliant.typing import ScalarKwargs
from narwhals._utils import Implementation, Version
from narwhals.typing import IntoDType, NonNestedLiteral
Incomplete: TypeAlias = Any
"""Escape hatch, but leaving a trace that this isn't ideal."""
_Vertical: TypeAlias = Literal[0]
_Horizontal: TypeAlias = Literal[1]
Axis: TypeAlias = Literal[_Vertical, _Horizontal]
VERTICAL: _Vertical = 0
HORIZONTAL: _Horizontal = 1
class PandasLikeNamespace(
EagerNamespace[
PandasLikeDataFrame,
PandasLikeSeries,
PandasLikeExpr,
NativeDataFrameT,
NativeSeriesT,
]
):
@property
def _dataframe(self) -> type[PandasLikeDataFrame]:
return PandasLikeDataFrame
@property
def _expr(self) -> type[PandasLikeExpr]:
return PandasLikeExpr
@property
def _series(self) -> type[PandasLikeSeries]:
return PandasLikeSeries
@property
def selectors(self) -> PandasSelectorNamespace:
return PandasSelectorNamespace.from_namespace(self)
def __init__(self, implementation: Implementation, version: Version) -> None:
self._implementation = implementation
self._version = version
def coalesce(self, *exprs: PandasLikeExpr) -> PandasLikeExpr:
def func(df: PandasLikeDataFrame) -> list[PandasLikeSeries]:
align = self._series._align_full_broadcast
series = align(*(s for _expr in exprs for s in _expr(df)))
return [
reduce(lambda x, y: x.fill_null(y, strategy=None, limit=None), series)
]
return self._expr._from_callable(
func=func,
depth=max(x._depth for x in exprs) + 1,
function_name="coalesce",
evaluate_output_names=combine_evaluate_output_names(*exprs),
alias_output_names=combine_alias_output_names(*exprs),
context=self,
)
def lit(self, value: NonNestedLiteral, dtype: IntoDType | None) -> PandasLikeExpr:
def _lit_pandas_series(df: PandasLikeDataFrame) -> PandasLikeSeries:
pandas_series = self._series.from_iterable(
data=[value],
name="literal",
index=df._native_frame.index[0:1],
context=self,
)
if dtype:
return pandas_series.cast(dtype)
return pandas_series
return PandasLikeExpr(
lambda df: [_lit_pandas_series(df)],
depth=0,
function_name="lit",
evaluate_output_names=lambda _df: ["literal"],
alias_output_names=None,
implementation=self._implementation,
version=self._version,
)
def len(self) -> PandasLikeExpr:
return PandasLikeExpr(
lambda df: [
self._series.from_iterable(
[len(df._native_frame)], name="len", index=[0], context=self
)
],
depth=0,
function_name="len",
evaluate_output_names=lambda _df: ["len"],
alias_output_names=None,
implementation=self._implementation,
version=self._version,
)
# --- horizontal ---
def sum_horizontal(self, *exprs: PandasLikeExpr) -> PandasLikeExpr:
def func(df: PandasLikeDataFrame) -> list[PandasLikeSeries]:
align = self._series._align_full_broadcast
it = chain.from_iterable(expr(df) for expr in exprs)
series = align(*it)
native_series = (s.fill_null(0, None, None) for s in series)
return [reduce(operator.add, native_series)]
return self._expr._from_callable(
func=func,
depth=max(x._depth for x in exprs) + 1,
function_name="sum_horizontal",
evaluate_output_names=combine_evaluate_output_names(*exprs),
alias_output_names=combine_alias_output_names(*exprs),
context=self,
)
def all_horizontal(
self, *exprs: PandasLikeExpr, ignore_nulls: bool
) -> PandasLikeExpr:
def func(df: PandasLikeDataFrame) -> list[PandasLikeSeries]:
align = self._series._align_full_broadcast
series = [s for _expr in exprs for s in _expr(df)]
if not ignore_nulls and any(
s.native.dtype == "object" and s.is_null().any() for s in series
):
# classical NumPy boolean columns don't support missing values, so
# only do the full scan with `is_null` if we have `object` dtype.
msg = "Cannot use `ignore_nulls=False` in `all_horizontal` for non-nullable NumPy-backed pandas Series when nulls are present."
raise ValueError(msg)
it = (
(
# NumPy-backed 'bool' dtype can't contain nulls so doesn't need filling.
s if is_non_nullable_boolean(s) else s.fill_null(True, None, None) # noqa: FBT003
for s in series
)
if ignore_nulls
else iter(series)
)
return [reduce(operator.and_, align(*it))]
return self._expr._from_callable(
func=func,
depth=max(x._depth for x in exprs) + 1,
function_name="all_horizontal",
evaluate_output_names=combine_evaluate_output_names(*exprs),
alias_output_names=combine_alias_output_names(*exprs),
context=self,
)
def any_horizontal(
self, *exprs: PandasLikeExpr, ignore_nulls: bool
) -> PandasLikeExpr:
def func(df: PandasLikeDataFrame) -> list[PandasLikeSeries]:
align = self._series._align_full_broadcast
series = [s for _expr in exprs for s in _expr(df)]
if not ignore_nulls and any(
s.native.dtype == "object" and s.is_null().any() for s in series
):
# classical NumPy boolean columns don't support missing values, so
# only do the full scan with `is_null` if we have `object` dtype.
msg = "Cannot use `ignore_nulls=False` in `any_horizontal` for non-nullable NumPy-backed pandas Series when nulls are present."
raise ValueError(msg)
it = (
(
# NumPy-backed 'bool' dtype can't contain nulls so doesn't need filling.
s if is_non_nullable_boolean(s) else s.fill_null(False, None, None) # noqa: FBT003
for s in series
)
if ignore_nulls
else iter(series)
)
return [reduce(operator.or_, align(*it))]
return self._expr._from_callable(
func=func,
depth=max(x._depth for x in exprs) + 1,
function_name="any_horizontal",
evaluate_output_names=combine_evaluate_output_names(*exprs),
alias_output_names=combine_alias_output_names(*exprs),
context=self,
)
def mean_horizontal(self, *exprs: PandasLikeExpr) -> PandasLikeExpr:
def func(df: PandasLikeDataFrame) -> list[PandasLikeSeries]:
expr_results = [s for _expr in exprs for s in _expr(df)]
align = self._series._align_full_broadcast
series = align(
*(s.fill_null(0, strategy=None, limit=None) for s in expr_results)
)
non_na = align(*(1 - s.is_null() for s in expr_results))
return [reduce(operator.add, series) / reduce(operator.add, non_na)]
return self._expr._from_callable(
func=func,
depth=max(x._depth for x in exprs) + 1,
function_name="mean_horizontal",
evaluate_output_names=combine_evaluate_output_names(*exprs),
alias_output_names=combine_alias_output_names(*exprs),
context=self,
)
def min_horizontal(self, *exprs: PandasLikeExpr) -> PandasLikeExpr:
def func(df: PandasLikeDataFrame) -> list[PandasLikeSeries]:
it = chain.from_iterable(expr(df) for expr in exprs)
align = self._series._align_full_broadcast
series = align(*it)
return [
PandasLikeSeries(
self.concat(
(s.to_frame() for s in series), how="horizontal"
)._native_frame.min(axis=1),
implementation=self._implementation,
version=self._version,
).alias(series[0].name)
]
return self._expr._from_callable(
func=func,
depth=max(x._depth for x in exprs) + 1,
function_name="min_horizontal",
evaluate_output_names=combine_evaluate_output_names(*exprs),
alias_output_names=combine_alias_output_names(*exprs),
context=self,
)
def max_horizontal(self, *exprs: PandasLikeExpr) -> PandasLikeExpr:
def func(df: PandasLikeDataFrame) -> list[PandasLikeSeries]:
it = chain.from_iterable(expr(df) for expr in exprs)
align = self._series._align_full_broadcast
series = align(*it)
return [
PandasLikeSeries(
self.concat(
(s.to_frame() for s in series), how="horizontal"
).native.max(axis=1),
implementation=self._implementation,
version=self._version,
).alias(series[0].name)
]
return self._expr._from_callable(
func=func,
depth=max(x._depth for x in exprs) + 1,
function_name="max_horizontal",
evaluate_output_names=combine_evaluate_output_names(*exprs),
alias_output_names=combine_alias_output_names(*exprs),
context=self,
)
@property
def _concat(self) -> _NativeConcat[NativeDataFrameT, NativeSeriesT]:
"""Concatenate pandas objects along a particular axis.
Return the **native** equivalent of `pd.concat`.
"""
return self._implementation.to_native_namespace().concat
def _concat_diagonal(self, dfs: Sequence[NativeDataFrameT], /) -> NativeDataFrameT:
if self._implementation.is_pandas() and self._backend_version < (3,):
return self._concat(dfs, axis=VERTICAL, copy=False)
return self._concat(dfs, axis=VERTICAL)
def _concat_horizontal(
self, dfs: Sequence[NativeDataFrameT | NativeSeriesT], /
) -> NativeDataFrameT:
if self._implementation.is_cudf():
with warnings.catch_warnings():
warnings.filterwarnings(
"ignore",
message="The behavior of array concatenation with empty entries is deprecated",
category=FutureWarning,
)
return self._concat(dfs, axis=HORIZONTAL)
elif self._implementation.is_pandas() and self._backend_version < (3,):
return self._concat(dfs, axis=HORIZONTAL, copy=False)
return self._concat(dfs, axis=HORIZONTAL)
def _concat_vertical(self, dfs: Sequence[NativeDataFrameT], /) -> NativeDataFrameT:
cols_0 = dfs[0].columns
for i, df in enumerate(dfs[1:], start=1):
cols_current = df.columns
if not (
(len(cols_current) == len(cols_0)) and (cols_current == cols_0).all()
):
msg = (
"unable to vstack, column names don't match:\n"
f" - dataframe 0: {cols_0.to_list()}\n"
f" - dataframe {i}: {cols_current.to_list()}\n"
)
raise TypeError(msg)
if self._implementation.is_pandas() and self._backend_version < (3,):
return self._concat(dfs, axis=VERTICAL, copy=False)
return self._concat(dfs, axis=VERTICAL)
def when(self, predicate: PandasLikeExpr) -> PandasWhen[NativeSeriesT]:
return PandasWhen[NativeSeriesT].from_expr(predicate, context=self)
def concat_str(
self, *exprs: PandasLikeExpr, separator: str, ignore_nulls: bool
) -> PandasLikeExpr:
string = self._version.dtypes.String()
def func(df: PandasLikeDataFrame) -> list[PandasLikeSeries]:
expr_results = [s for _expr in exprs for s in _expr(df)]
align = self._series._align_full_broadcast
series = align(*(s.cast(string) for s in expr_results))
null_mask = align(*(s.is_null() for s in expr_results))
if not ignore_nulls:
null_mask_result = reduce(operator.or_, null_mask)
result = reduce(lambda x, y: x + separator + y, series).zip_with(
~null_mask_result, None
)
else:
# NOTE: Trying to help `mypy` later
# error: Cannot determine type of "values" [has-type]
values: list[PandasLikeSeries]
init_value, *values = [
s.zip_with(~nm, "") for s, nm in zip(series, null_mask)
]
sep_array = init_value.from_iterable(
data=[separator] * len(init_value),
name="sep",
index=init_value.native.index,
context=self,
)
separators = (sep_array.zip_with(~nm, "") for nm in null_mask[:-1])
result = reduce(
operator.add, (s + v for s, v in zip(separators, values)), init_value
)
return [result]
return self._expr._from_callable(
func=func,
depth=max(x._depth for x in exprs) + 1,
function_name="concat_str",
evaluate_output_names=combine_evaluate_output_names(*exprs),
alias_output_names=combine_alias_output_names(*exprs),
context=self,
)
class _NativeConcat(Protocol[NativeDataFrameT, NativeSeriesT]):
@overload
def __call__(
self,
objs: Iterable[NativeDataFrameT],
*,
axis: _Vertical,
copy: bool | None = ...,
) -> NativeDataFrameT: ...
@overload
def __call__(
self, objs: Iterable[NativeSeriesT], *, axis: _Vertical, copy: bool | None = ...
) -> NativeSeriesT: ...
@overload
def __call__(
self,
objs: Iterable[NativeDataFrameT | NativeSeriesT],
*,
axis: _Horizontal,
copy: bool | None = ...,
) -> NativeDataFrameT: ...
@overload
def __call__(
self,
objs: Iterable[NativeDataFrameT | NativeSeriesT],
*,
axis: Axis,
copy: bool | None = ...,
) -> NativeDataFrameT | NativeSeriesT: ...
def __call__(
self,
objs: Iterable[NativeDataFrameT | NativeSeriesT],
*,
axis: Axis,
copy: bool | None = None,
) -> NativeDataFrameT | NativeSeriesT: ...
class PandasWhen(
EagerWhen[PandasLikeDataFrame, PandasLikeSeries, PandasLikeExpr, NativeSeriesT]
):
@property
# Signature of "_then" incompatible with supertype "CompliantWhen"
# ArrowWhen seems to follow the same pattern, but no mypy complaint there?
def _then(self) -> type[PandasThen]: # type: ignore[override]
return PandasThen
def _if_then_else(
self,
when: NativeSeriesT,
then: NativeSeriesT,
otherwise: NativeSeriesT | NonNestedLiteral,
) -> NativeSeriesT:
where: Incomplete = then.where
return where(when) if otherwise is None else where(when, otherwise)
class PandasThen(
CompliantThen[PandasLikeDataFrame, PandasLikeSeries, PandasLikeExpr, PandasWhen],
PandasLikeExpr,
):
_depth: int = 0
_scalar_kwargs: ScalarKwargs = {} # noqa: RUF012
_function_name: str = "whenthen"