# -*- coding: utf-8 -*-
# SPDX-FileCopyrightText: 2016-2025 PyThaiNLP Project
# SPDX-FileType: SOURCE
# SPDX-License-Identifier: Apache-2.0
"""
Thai collation (sorted according to Thai dictionary order)
Simple implementation using regular expressions
"""
import re
from typing import Iterable, List
_RE_TONE = re.compile(r"[็-์]")
_RE_LV_C = re.compile(r"([เ-ไ])([ก-ฮ])")
def _thkey(word: str) -> str:
cv = _RE_TONE.sub("", word) # remove tone
cv = _RE_LV_C.sub("\\2\\1", cv) # switch lead vowel
tone_match = _RE_TONE.search(word)
tone = tone_match.group() if tone_match else ""
return cv + tone
[docs]
def collate(data: Iterable, reverse: bool = False) -> List[str]:
"""
This function sorts strings (almost) according to Thai dictionary.
Important notes: this implementation ignores tone marks and symbols
:param data: a list of words to be sorted
:type data: Iterable
:param reverse: If `reverse` is set to **True** the result will be
sorted in descending order. Otherwise, the result
will be sorted in ascending order, defaults to False
:type reverse: bool, optional
:return: a list of strings, sorted alphabetically, (almost) according to
Thai dictionary
:rtype: List[str]
:Example:
::
from pythainlp.util import collate
collate(['ไก่', 'เกิด', 'กาล', 'เป็ด', 'หมู', 'วัว', 'วันที่'])
# output: ['กาล', 'เกิด', 'ไก่', 'เป็ด', 'วันที่', 'วัว', 'หมู']
collate(['ไก่', 'เกิด', 'กาล', 'เป็ด', 'หมู', 'วัว', 'วันที่'], \\
reverse=True)
# output: ['หมู', 'วัว', 'วันที่', 'เป็ด', 'ไก่', 'เกิด', 'กาล']
"""
return sorted(data, key=_thkey, reverse=reverse)