team-10/env/Lib/site-packages/narwhals/_ibis/expr_str.py
2025-08-02 07:34:44 +02:00

132 lines
4.9 KiB
Python

from __future__ import annotations
from typing import TYPE_CHECKING, Any, Callable, cast
import ibis
import ibis.expr.types as ir
from ibis.expr.datatypes import Timestamp
from narwhals._compliant import LazyExprNamespace
from narwhals._compliant.any_namespace import StringNamespace
from narwhals._ibis.utils import lit
from narwhals._utils import _is_naive_format, not_implemented
if TYPE_CHECKING:
from narwhals._ibis.expr import IbisExpr
class IbisExprStringNamespace(LazyExprNamespace["IbisExpr"], StringNamespace["IbisExpr"]):
def starts_with(self, prefix: str) -> IbisExpr:
def fn(expr: ir.StringColumn) -> ir.BooleanValue:
return expr.startswith(prefix)
return self.compliant._with_callable(fn)
def ends_with(self, suffix: str) -> IbisExpr:
def fn(expr: ir.StringColumn) -> ir.BooleanValue:
return expr.endswith(suffix)
return self.compliant._with_callable(fn)
def contains(self, pattern: str, *, literal: bool) -> IbisExpr:
def fn(expr: ir.StringColumn) -> ir.BooleanValue:
return expr.contains(pattern) if literal else expr.re_search(pattern)
return self.compliant._with_callable(fn)
def slice(self, offset: int, length: int | None) -> IbisExpr:
def fn(expr: ir.StringColumn) -> ir.StringValue:
return expr.substr(start=offset, length=length)
return self.compliant._with_callable(fn)
def split(self, by: str) -> IbisExpr:
def fn(expr: ir.StringColumn) -> ir.ArrayValue:
return expr.split(by)
return self.compliant._with_callable(fn)
def len_chars(self) -> IbisExpr:
return self.compliant._with_callable(lambda expr: expr.length())
def to_lowercase(self) -> IbisExpr:
return self.compliant._with_callable(lambda expr: expr.lower())
def to_uppercase(self) -> IbisExpr:
return self.compliant._with_callable(lambda expr: expr.upper())
def strip_chars(self, characters: str | None) -> IbisExpr:
if characters is not None:
msg = "Ibis does not support `characters` argument in `str.strip_chars`"
raise NotImplementedError(msg)
return self.compliant._with_callable(lambda expr: expr.strip())
def _replace_all(self, pattern: str, value: str) -> Callable[..., ir.StringValue]:
def fn(expr: ir.StringColumn) -> ir.StringValue:
return expr.re_replace(pattern, value)
return fn
def _replace_all_literal(
self, pattern: str, value: str
) -> Callable[..., ir.StringValue]:
def fn(expr: ir.StringColumn) -> ir.StringValue:
return expr.replace(pattern, value) # pyright: ignore[reportArgumentType]
return fn
def replace_all(self, pattern: str, value: str, *, literal: bool) -> IbisExpr:
fn = self._replace_all_literal if literal else self._replace_all
return self.compliant._with_callable(fn(pattern, value))
def _to_datetime(self, format: str) -> Callable[..., ir.TimestampValue]:
def fn(expr: ir.StringColumn) -> ir.TimestampValue:
return expr.as_timestamp(format)
return fn
def _to_datetime_naive(self, format: str) -> Callable[..., ir.TimestampValue]:
def fn(expr: ir.StringColumn) -> ir.TimestampValue:
dtype: Any = Timestamp(timezone=None)
return expr.as_timestamp(format).cast(dtype)
return fn
def to_datetime(self, format: str | None) -> IbisExpr:
if format is None:
msg = "Cannot infer format with Ibis backend"
raise NotImplementedError(msg)
fn = self._to_datetime_naive if _is_naive_format(format) else self._to_datetime
return self.compliant._with_callable(fn(format))
def to_date(self, format: str | None) -> IbisExpr:
if format is None:
msg = "Cannot infer format with Ibis backend"
raise NotImplementedError(msg)
def fn(expr: ir.StringColumn) -> ir.DateValue:
return expr.as_date(format)
return self.compliant._with_callable(fn)
def zfill(self, width: int) -> IbisExpr:
def func(expr: ir.StringColumn) -> ir.Value:
length = expr.length()
less_than_width = length < lit(width)
zero, hyphen, plus = "0", "-", "+"
starts_with_minus = expr.startswith(hyphen)
starts_with_plus = expr.startswith(plus)
one = cast("ir.IntegerScalar", lit(1))
sub_length = cast("ir.IntegerValue", length - one)
substring = expr.substr(one, sub_length).lpad(width - 1, zero)
return ibis.cases(
(starts_with_minus & less_than_width, (substring.lpad(width, hyphen))),
(starts_with_plus & less_than_width, (substring.lpad(width, plus))),
(less_than_width, expr.lpad(width, zero)),
else_=expr,
)
return self.compliant._with_callable(func)
replace = not_implemented()