File size: 3,370 Bytes
e4b9a7b | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 | # -*- coding: utf-8 -*-
# SPDX-FileCopyrightText: 2016-2025 PyThaiNLP Project
# SPDX-FileType: SOURCE
# SPDX-License-Identifier: Apache-2.0
"""
Check if a word is a "native Thai word"
Adapted from
https://github.com/wannaphong/open-thai-nlp-document/blob/master/check_thai_word.md
References
- ทีมงานทรูปลูกปัญญา 2015. ลักษณะของคำไทยแท้ \
http://www.trueplookpanya.com/learning/detail/30589-043067
- วารุณี บำรุงรส 2010. คำไทยแท้ https://www.gotoknow.org/posts/377619
"""
import re
_THANTHAKHAT_CHAR = "\u0e4c" # Thanthakhat (cancellation of sound)
# Non-native Thai characters
_TH_NON_NATIVE_CHARS = {
"ฆ",
"ณ",
"ฌ",
"ฎ",
"ฏ",
"ฐ",
"ฑ",
"ฒ",
"ธ",
"ศ",
"ษ",
"ฬ",
_THANTHAKHAT_CHAR,
}
# Native Thai final consonants
_TH_NATIVE_FINALS = {"ก", "ด", "บ", "น", "ง", "ม", "ย", "ว"}
# Known native Thai words (exceptions)
_TH_NATIVE_WORDS = {
"ฆ่า",
"เฆี่ยน",
"ศึก",
"ศอก",
"เศิก",
"เศร้า",
"ธ",
"ณ",
"ฯพณฯ",
"ใหญ่",
"หญ้า",
"ควาย",
"ความ",
"กริ่งเกรง",
"ผลิ",
}
# Diphthong prefixes (can start native Thai word)
_TH_PREFIX_DIPHTHONG = {"กะ", "กระ", "ปะ", "ประ"}
# Thai consonant filter
# O ANG (U+0E2D) is omitted, as it can be considered as vowel
_TH_CONSONANTS_PATTERN = re.compile(r"[ก-ฬฮ]", re.U)
def is_native_thai(word: str) -> bool:
"""
Check if a word is an "native Thai word" (Thai: "คำไทยแท้")
This function is based on a simple heuristic algorithm
and cannot be entirely reliable.
:param str word: word
:return: True or False
:rtype: bool
:Example:
English word::
from pythainlp.util import is_native_thai
is_native_thai("Avocado")
# output: False
Native Thai word::
is_native_thai("มะม่วง")
# output: True
is_native_thai("ตะวัน")
# output: True
Non-native Thai word::
is_native_thai("สามารถ")
# output: False
is_native_thai("อิสริยาภรณ์")
# output: False
"""
if not isinstance(word, str) or not word.strip():
return False
word = word.strip()
# Known native Thai words (exceptions)
if word in _TH_NATIVE_WORDS:
return True
# If a word contains non-Thai chars, it is not a native Thai
if any(ch in word for ch in _TH_NON_NATIVE_CHARS):
return False
# If it does not contain any Thai consonants -> it cannot be Thai
chs = re.findall(_TH_CONSONANTS_PATTERN, word)
if not chs:
return False
# If there's only one Thai consonant -> it can be a native Thai
if len(chs) == 1:
return True
# If a word ends with native final, it can be a native Thai
if word[-1] in _TH_NATIVE_FINALS:
return True
# Note: This will not work, as it check the whole word, not the prefix.
# Prefix-sensitive tokenization is required in order to be able to check this.
if word in _TH_PREFIX_DIPHTHONG:
return True
return False
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