81 lines
3.0 KiB
Python
81 lines
3.0 KiB
Python
from __future__ import annotations
|
|
|
|
from typing import TYPE_CHECKING
|
|
|
|
import dask.dataframe as dd
|
|
|
|
from narwhals._compliant import LazyExprNamespace
|
|
from narwhals._compliant.any_namespace import StringNamespace
|
|
from narwhals._utils import not_implemented
|
|
|
|
if TYPE_CHECKING:
|
|
import dask.dataframe.dask_expr as dx
|
|
|
|
from narwhals._dask.expr import DaskExpr
|
|
|
|
|
|
class DaskExprStringNamespace(LazyExprNamespace["DaskExpr"], StringNamespace["DaskExpr"]):
|
|
def len_chars(self) -> DaskExpr:
|
|
return self.compliant._with_callable(lambda expr: expr.str.len())
|
|
|
|
def replace(
|
|
self, value: DaskExpr, pattern: str, *, literal: bool, n: int
|
|
) -> DaskExpr:
|
|
if not value._metadata.is_literal:
|
|
msg = "dask backed `Expr.str.replace` only supports str replacement values"
|
|
raise TypeError(msg)
|
|
|
|
def _replace(expr: dx.Series, value: dx.Series) -> dx.Series:
|
|
# OK to call `compute` here as `value` is just a literal expression.
|
|
return expr.str.replace( # pyright: ignore[reportAttributeAccessIssue]
|
|
pattern, value.compute(), regex=not literal, n=n
|
|
)
|
|
|
|
return self.compliant._with_callable(_replace, value=value)
|
|
|
|
def replace_all(self, value: DaskExpr, pattern: str, *, literal: bool) -> DaskExpr:
|
|
return self.replace(value, pattern, literal=literal, n=-1)
|
|
|
|
def strip_chars(self, characters: str | None) -> DaskExpr:
|
|
return self.compliant._with_callable(lambda expr: expr.str.strip(characters))
|
|
|
|
def starts_with(self, prefix: str) -> DaskExpr:
|
|
return self.compliant._with_callable(lambda expr: expr.str.startswith(prefix))
|
|
|
|
def ends_with(self, suffix: str) -> DaskExpr:
|
|
return self.compliant._with_callable(lambda expr: expr.str.endswith(suffix))
|
|
|
|
def contains(self, pattern: str, *, literal: bool) -> DaskExpr:
|
|
return self.compliant._with_callable(
|
|
lambda expr: expr.str.contains(pat=pattern, regex=not literal)
|
|
)
|
|
|
|
def slice(self, offset: int, length: int | None) -> DaskExpr:
|
|
return self.compliant._with_callable(
|
|
lambda expr: expr.str.slice(
|
|
start=offset, stop=offset + length if length else None
|
|
)
|
|
)
|
|
|
|
def split(self, by: str) -> DaskExpr:
|
|
return self.compliant._with_callable(lambda expr: expr.str.split(pat=by))
|
|
|
|
def to_datetime(self, format: str | None) -> DaskExpr:
|
|
return self.compliant._with_callable(
|
|
lambda expr: dd.to_datetime(expr, format=format)
|
|
)
|
|
|
|
def to_uppercase(self) -> DaskExpr:
|
|
return self.compliant._with_callable(lambda expr: expr.str.upper())
|
|
|
|
def to_lowercase(self) -> DaskExpr:
|
|
return self.compliant._with_callable(lambda expr: expr.str.lower())
|
|
|
|
def to_titlecase(self) -> DaskExpr:
|
|
return self.compliant._with_callable(lambda expr: expr.str.title())
|
|
|
|
def zfill(self, width: int) -> DaskExpr:
|
|
return self.compliant._with_callable(lambda expr: expr.str.zfill(width))
|
|
|
|
to_date = not_implemented()
|