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Buffteks-Website/buffteks/lib/python3.12/site-packages/narwhals/_pandas_like/namespace.py
2025-05-08 21:10:14 -05:00

335 lines
12 KiB
Python

from __future__ import annotations
import operator
from functools import reduce
from typing import TYPE_CHECKING
from typing import Any
from typing import Iterable
from typing import Literal
from narwhals._compliant import CompliantThen
from narwhals._compliant import EagerNamespace
from narwhals._compliant import EagerWhen
from narwhals._expression_parsing import combine_alias_output_names
from narwhals._expression_parsing import 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.utils import align_series_full_broadcast
from narwhals._pandas_like.utils import diagonal_concat
from narwhals._pandas_like.utils import horizontal_concat
from narwhals._pandas_like.utils import vertical_concat
from narwhals.utils import import_dtypes_module
if TYPE_CHECKING:
import pandas as pd
from typing_extensions import Self
from narwhals.dtypes import DType
from narwhals.utils import Implementation
from narwhals.utils import Version
class PandasLikeNamespace(
EagerNamespace[PandasLikeDataFrame, PandasLikeSeries, PandasLikeExpr]
):
@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: Self) -> PandasSelectorNamespace:
return PandasSelectorNamespace(self)
# --- not in spec ---
def __init__(
self: Self,
implementation: Implementation,
backend_version: tuple[int, ...],
version: Version,
) -> None:
self._implementation = implementation
self._backend_version = backend_version
self._version = version
def lit(self: Self, value: Any, dtype: DType | type[DType] | 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,
backend_version=self._backend_version,
version=self._version,
)
def len(self: 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,
backend_version=self._backend_version,
version=self._version,
)
# --- horizontal ---
def sum_horizontal(self: Self, *exprs: PandasLikeExpr) -> PandasLikeExpr:
def func(df: PandasLikeDataFrame) -> list[PandasLikeSeries]:
series = [s for _expr in exprs for s in _expr(df)]
series = align_series_full_broadcast(*series)
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: Self, *exprs: PandasLikeExpr) -> PandasLikeExpr:
def func(df: PandasLikeDataFrame) -> list[PandasLikeSeries]:
series = align_series_full_broadcast(
*(s for _expr in exprs for s in _expr(df))
)
return [reduce(operator.and_, series)]
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: Self, *exprs: PandasLikeExpr) -> PandasLikeExpr:
def func(df: PandasLikeDataFrame) -> list[PandasLikeSeries]:
series = align_series_full_broadcast(
*(s for _expr in exprs for s in _expr(df))
)
return [reduce(operator.or_, series)]
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: Self, *exprs: PandasLikeExpr) -> PandasLikeExpr:
def func(df: PandasLikeDataFrame) -> list[PandasLikeSeries]:
expr_results = [s for _expr in exprs for s in _expr(df)]
series = align_series_full_broadcast(
*(s.fill_null(0, strategy=None, limit=None) for s in expr_results)
)
non_na = align_series_full_broadcast(*(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: Self, *exprs: PandasLikeExpr) -> PandasLikeExpr:
def func(df: PandasLikeDataFrame) -> list[PandasLikeSeries]:
series = [s for _expr in exprs for s in _expr(df)]
series = align_series_full_broadcast(*series)
return [
PandasLikeSeries(
self.concat(
(s.to_frame() for s in series), how="horizontal"
)._native_frame.min(axis=1),
implementation=self._implementation,
backend_version=self._backend_version,
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: Self, *exprs: PandasLikeExpr) -> PandasLikeExpr:
def func(df: PandasLikeDataFrame) -> list[PandasLikeSeries]:
series = [s for _expr in exprs for s in _expr(df)]
series = align_series_full_broadcast(*series)
return [
PandasLikeSeries(
self.concat(
(s.to_frame() for s in series), how="horizontal"
)._native_frame.max(axis=1),
implementation=self._implementation,
backend_version=self._backend_version,
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,
)
def concat(
self: Self,
items: Iterable[PandasLikeDataFrame],
*,
how: Literal["horizontal", "vertical", "diagonal"],
) -> PandasLikeDataFrame:
dfs: list[Any] = [item._native_frame for item in items]
if how == "horizontal":
return PandasLikeDataFrame(
horizontal_concat(
dfs,
implementation=self._implementation,
backend_version=self._backend_version,
),
implementation=self._implementation,
backend_version=self._backend_version,
version=self._version,
validate_column_names=True,
)
if how == "vertical":
return PandasLikeDataFrame(
vertical_concat(
dfs,
implementation=self._implementation,
backend_version=self._backend_version,
),
implementation=self._implementation,
backend_version=self._backend_version,
version=self._version,
validate_column_names=True,
)
if how == "diagonal":
return PandasLikeDataFrame(
diagonal_concat(
dfs,
implementation=self._implementation,
backend_version=self._backend_version,
),
implementation=self._implementation,
backend_version=self._backend_version,
version=self._version,
validate_column_names=True,
)
raise NotImplementedError
def when(self: Self, predicate: PandasLikeExpr) -> PandasWhen:
return PandasWhen.from_expr(predicate, context=self)
def concat_str(
self: Self,
*exprs: PandasLikeExpr,
separator: str,
ignore_nulls: bool,
) -> PandasLikeExpr:
dtypes = import_dtypes_module(self._version)
def func(df: PandasLikeDataFrame) -> list[PandasLikeSeries]:
expr_results = [s for _expr in exprs for s in _expr(df)]
series = align_series_full_broadcast(
*(s.cast(dtypes.String()) for s in expr_results)
)
null_mask = align_series_full_broadcast(*(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:
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 PandasWhen(
EagerWhen[PandasLikeDataFrame, PandasLikeSeries, PandasLikeExpr, "pd.Series[Any]"]
):
@property
def _then(self) -> type[PandasThen]:
return PandasThen
def _if_then_else(
self, when: pd.Series[Any], then: pd.Series[Any], otherwise: Any, /
) -> pd.Series[Any]:
return then.where(when) if otherwise is None else then.where(when, otherwise)
class PandasThen(
CompliantThen[PandasLikeDataFrame, PandasLikeSeries, PandasLikeExpr], PandasLikeExpr
): ...