# SPDX-License-Identifier: MIT
# Copyright (C) 2022 Max Bachmann
from __future__ import annotations
import re
_alnum_regex = re.compile(r"(?ui)\W")
def default_process(sentence: str) -> str:
"""
This function preprocesses a string by:
* removing all non alphanumeric characters
* trimming whitespaces
* converting all characters to lower case
Parameters
----------
sentence : str
String to preprocess
Returns
-------
processed_string : str
processed string
"""
string_out = _alnum_regex.sub(" ", sentence)
return string_out.strip().lower()