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from __future__ import annotations
import string
from typing import TYPE_CHECKING
import pyarrow.compute as pc
from narwhals._arrow.utils import ArrowSeriesNamespace, lit, parse_datetime_format
if TYPE_CHECKING:
from narwhals._arrow.series import ArrowSeries
class ArrowSeriesStringNamespace(ArrowSeriesNamespace):
def len_chars(self) -> ArrowSeries:
return self.with_native(pc.utf8_length(self.native))
def replace(self, pattern: str, value: str, *, literal: bool, n: int) -> ArrowSeries:
fn = pc.replace_substring if literal else pc.replace_substring_regex
arr = fn(self.native, pattern, replacement=value, max_replacements=n)
return self.with_native(arr)
def replace_all(self, pattern: str, value: str, *, literal: bool) -> ArrowSeries:
return self.replace(pattern, value, literal=literal, n=-1)
def strip_chars(self, characters: str | None) -> ArrowSeries:
return self.with_native(
pc.utf8_trim(self.native, characters or string.whitespace)
)
def starts_with(self, prefix: str) -> ArrowSeries:
return self.with_native(pc.equal(self.slice(0, len(prefix)).native, lit(prefix)))
def ends_with(self, suffix: str) -> ArrowSeries:
return self.with_native(
pc.equal(self.slice(-len(suffix), None).native, lit(suffix))
)
def contains(self, pattern: str, *, literal: bool) -> ArrowSeries:
check_func = pc.match_substring if literal else pc.match_substring_regex
return self.with_native(check_func(self.native, pattern))
def slice(self, offset: int, length: int | None) -> ArrowSeries:
stop = offset + length if length is not None else None
return self.with_native(
pc.utf8_slice_codeunits(self.native, start=offset, stop=stop)
)
def split(self, by: str) -> ArrowSeries:
split_series = pc.split_pattern(self.native, by) # type: ignore[call-overload]
return self.with_native(split_series)
def to_datetime(self, format: str | None) -> ArrowSeries:
format = parse_datetime_format(self.native) if format is None else format
timestamp_array = pc.strptime(self.native, format=format, unit="us")
return self.with_native(timestamp_array)
def to_uppercase(self) -> ArrowSeries:
return self.with_native(pc.utf8_upper(self.native))
def to_lowercase(self) -> ArrowSeries:
return self.with_native(pc.utf8_lower(self.native))
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