ZombitThai-GPT-128K / advanced_thai_tokenizer.py
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"""
Advanced Thai Tokenizer for ZombitThai-GPT
Features:
- Thai-specific tokenization with syllable awareness
- Continuous learning system for new words
- Duplicate prevention mechanism
- Dynamic vocabulary expansion
- Memory-efficient token management
"""
import json
import os
import re
import hashlib
from typing import List, Dict, Set, Tuple, Optional
from collections import defaultdict, Counter
import pickle
from pathlib import Path
import logging
# Import pythainlp for advanced Thai word segmentation
try:
from pythainlp import word_tokenize
PYTHAINLP_AVAILABLE = True
except ImportError:
PYTHAINLP_AVAILABLE = False
logging.warning("pythainlp not available. Using fallback Thai segmentation.")
# Set up logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)
class AdvancedThaiTokenizer:
"""
Ultra-Advanced Thai Tokenizer with Multi-Engine Support and Context-Aware Segmentation
Features:
- Multi-engine PyThaiNLP integration
- Context-aware word segmentation
- Domain-specific dictionaries
- Subword tokenization (BPE)
- Intelligent caching system
- Quality metrics and evaluation
- Adaptive learning from corrections
"""
def __init__(self, vocab_size: int = 50000, min_freq: int = 1, enable_cache: bool = True):
self.vocab_size = vocab_size
self.min_freq = min_freq
self.vocab: Dict[str, int] = {}
self.reverse_vocab: Dict[int, str] = {}
self.word_freq: Counter = Counter()
self.syllable_patterns: Set[str] = set()
self.compound_words: Set[str] = set()
self.learning_enabled = True
self.enable_cache = enable_cache
# Advanced caching system
self.tokenization_cache: Dict[str, List[str]] = {}
self.cache_hits = 0
self.cache_misses = 0
# Multi-engine configuration
self.pythainlp_engines = ["newmm", "longest", "multi_cut"]
self.current_engine = "newmm"
# Context-aware segmentation
self.context_patterns = self._load_context_patterns()
# Domain-specific dictionaries
self.domain_dictionaries = self._load_domain_dictionaries()
# Quality metrics
self.segmentation_quality = {
"total_segments": 0,
"correct_segments": 0,
"avg_confidence": 0.0
}
# Special tokens
self.special_tokens = {
"<pad>": 0,
"<bos>": 1,
"<eos>": 2,
"<unk>": 3,
"<mask>": 4,
"<newline>": 5,
}
# Thai-specific patterns
self.thai_consonants = "กขฃคฅฆงจฉชซฌญฎฏฐฑฒณดตถทธนบปผฝพฟภมยรลวศษสหฬอฮ"
self.thai_vowels = "ะาำิีึืุูเแโใไๅๆ็่้๊๋์"
self.thai_tonemarks = "่้๊๋์"
# Thai word dictionary for better segmentation
self.thai_dictionary = self._load_thai_dictionary()
self.max_word_length = max(len(word) for word in self.thai_dictionary) if self.thai_dictionary else 10
# Initialize vocabulary with special tokens
self._init_vocab()
def _init_vocab(self):
"""Initialize vocabulary with special tokens."""
self.vocab = self.special_tokens.copy()
self.reverse_vocab = {v: k for k, v in self.vocab.items()}
self.next_token_id = len(self.special_tokens)
def _is_thai_text(self, text: str) -> bool:
"""Check if text contains Thai characters."""
thai_chars = set(self.thai_consonants + "ะาำิีึืุูเแโใไๅๆ็่้๊๋์")
return any(char in thai_chars for char in text)
def _extract_syllables(self, text: str) -> List[str]:
"""Extract syllables from Thai text using linguistic patterns."""
syllables = []
# Split by whitespace first
words = text.split()
for word in words:
if len(word) <= 2:
# Very short words are treated as single syllables
syllables.append(word)
elif len(word) <= 4:
# Short words: try to keep as whole words if they're common
if word in self.vocab or self.word_freq.get(word, 0) > 0:
syllables.append(word)
else:
syllables.extend(list(word)) # Fallback to characters
else:
# Long words: apply syllable segmentation
word_syllables = self._segment_word_into_syllables(word)
syllables.extend(word_syllables)
return syllables
def _segment_word_into_syllables(self, word: str) -> List[str]:
"""Segment a long Thai word into syllables using advanced linguistic rules."""
if not word:
return []
# Use dictionary-based approach first for known words
if word in self.vocab or self.word_freq.get(word, 0) > 0:
return [word]
# Apply advanced syllable segmentation
syllables = []
i = 0
while i < len(word):
syllable = self._extract_single_syllable(word, i)
if syllable:
syllables.append(syllable)
i += len(syllable)
else:
# Fallback: take single character
syllables.append(word[i])
i += 1
return syllables
def _extract_single_syllable(self, word: str, start_pos: int) -> str:
"""Extract a single syllable from word starting at given position."""
if start_pos >= len(word):
return ""
# Enhanced Thai syllable patterns with better priority
patterns = [
# Most common Thai syllable patterns
self._match_pattern(word, start_pos, "CVC"), # เช่น: มาก, คน, ดี
self._match_pattern(word, start_pos, "CV"), # เช่น: มา, ไป, เขา
self._match_pattern(word, start_pos, "CCV"), # เช่น: ใคร, ไทย, ใช่
self._match_pattern(word, start_pos, "CCVC"), # เช่น: ประเทศ, ทำงาน
self._match_pattern(word, start_pos, "CVCC"), # เช่น: วันนี, แต่ไม่ค่อยมี
self._match_pattern(word, start_pos, "CC"), # เช่น: ครับ, ค่ะ (short forms)
]
# Return first matching pattern
for pattern in patterns:
if pattern:
return pattern
# Enhanced fallback: try to find meaningful Thai units
return self._enhanced_fallback_extraction(word, start_pos)
def _match_pattern(self, word: str, start: int, pattern: str) -> str:
"""Match Thai syllable pattern starting from given position."""
if start >= len(word):
return ""
i = start
matched = ""
for pattern_char in pattern:
if i >= len(word):
return "" # Pattern too long for remaining text
if pattern_char == 'C': # Consonant
if word[i] in self.thai_consonants:
matched += word[i]
i += 1
else:
return "" # Pattern doesn't match
elif pattern_char == 'V': # Vowel
if word[i] in (self.thai_vowels + self.thai_tonemarks):
matched += word[i]
i += 1
else:
return "" # Pattern doesn't match
else:
return "" # Unknown pattern character
return matched
def _fallback_syllable_extraction(self, word: str, start: int) -> str:
"""Fallback syllable extraction when patterns don't match."""
if start >= len(word):
return ""
# Simple rule-based approach
i = start
# Take initial consonants (up to 2)
while i < len(word) and word[i] in self.thai_consonants and (i - start) < 2:
i += 1
# Take vowels and tone marks
while i < len(word) and word[i] in (self.thai_vowels + self.thai_tonemarks):
i += 1
# Take final consonant if present
if i < len(word) and word[i] in self.thai_consonants:
i += 1
syllable = word[start:i]
return syllable if syllable else word[start] # At least one character
def _enhanced_fallback_extraction(self, word: str, start: int) -> str:
"""Enhanced fallback extraction for Thai text."""
if start >= len(word):
return ""
# Try to find Thai character groups
i = start
# Look for Thai consonant + vowel combinations
if i < len(word) and word[i] in self.thai_consonants:
syllable = word[i]
i += 1
# Add vowels and tone marks
while i < len(word) and word[i] in (self.thai_vowels + self.thai_tonemarks):
syllable += word[i]
i += 1
# Add final consonant if present
if i < len(word) and word[i] in self.thai_consonants:
syllable += word[i]
i += 1
if len(syllable) > 1: # Return only if we got more than just a consonant
return syllable
# If Thai pattern fails, try to find word-like sequences
# Look for sequences that might be meaningful
for length in range(min(4, len(word) - start), 0, -1):
candidate = word[start:start + length]
# Check if it contains Thai characters
if any(c in (self.thai_consonants + self.thai_vowels) for c in candidate):
return candidate
# Final fallback: single character
return word[start]
def _load_context_patterns(self) -> Dict[str, List[str]]:
"""Load context-aware segmentation patterns."""
return {
"question": ["อะไร", "ทำไม", "อย่างไร", "เมื่อไหร่", "ที่ไหน", "ใคร"],
"greeting": ["สวัสดี", "ครับ", "คะ", "ค่ะ", "นะครับ", "นะคะ"],
"polite": ["กรุณา", "ขอโทษ", "ขอบคุณ", "ยินดี", "ด้วย"],
"time": ["วันนี้", "เมื่อวาน", "พรุ่งนี้", "เช้า", "บ่าย", "เย็น", "คืน"],
"quantity": ["หนึ่ง", "สอง", "สาม", "ทั้งหมด", "หลาย", "บาง"],
"negation": ["ไม่", "ไม่ได้", "ไม่มี", "ไม่ได้"],
"emphasis": ["มาก", "ที่สุด", "จริงๆ", "แน่นอน", "จริง"]
}
def _load_domain_dictionaries(self) -> Dict[str, Set[str]]:
"""Load domain-specific dictionaries."""
return {
"tech": {
"ปัญญาประดิษฐ์", "แมชชีนเลิร์นนิง", "ดีปเลิร์นนิง", "อัลกอริทึม",
"โมเดล", "ข้อมูล", "การฝึก", "การทดสอบ", "ความแม่นยำ", "คลัสเตอร์",
"นิวรัลเน็ตเวิร์ก", "บิ๊กดาต้า", "ไอโอที", "บล็อกเชน", "คลาวด์"
},
"medical": {
"โรงพยาบาล", "แพทย์", "พยาบาล", "ยา", "อาการ", "ป่วย", "หาย",
"สุขภาพ", "โรค", "อาการป่วย", "การรักษา", "ผู้ป่วย", "การวินิจฉัย"
},
"business": {
"บริษัท", "ธุรกิจ", "ลูกค้า", "ขาย", "ซื้อ", "เงิน", "ราคา",
"ตลาด", "งาน", "เงินเดือน", "สัญญา", "เอกสาร", "กำไร", "ขาดทุน"
},
"education": {
"โรงเรียน", "มหาวิทยาลัย", "นักเรียน", "นักศึกษา", "ครู", "อาจารย์",
"เรียน", "สอน", "สอบ", "เกรด", "วิชา", "ห้องเรียน", "ห้องสมุด"
}
}
def _load_thai_dictionary(self) -> Set[str]:
"""Load comprehensive Thai word dictionary for better segmentation."""
# Basic Thai word dictionary (can be expanded)
thai_words = {
# Common words
"สวัสดี", "ครับ", "คะ", "ค่ะ", "ครับ", "นะ", "นะครับ", "นะคะ",
"และ", "หรือ", "แต่", "แล้ว", "ก็", "ได้", "มี", "เป็น", "ไป", "มา",
"จะ", "ต้อง", "ไม่", "ใช่", "ใช่ไหม", "ทำไม", "อะไร", "เมื่อไหร่",
"ที่ไหน", "อย่างไร", "อย่างไรบ้าง", "สบายดี", "ขอบคุณ", "ยินดี",
# Technology terms
"คอมพิวเตอร์", "อินเทอร์เน็ต", "โทรศัพท์", "มือถือ", "แท็บเล็ต",
"ปัญญาประดิษฐ์", "แมชชีนเลิร์นนิง", "ดีปเลิร์นนิง", "ข้อมูล",
"โปรแกรม", "ซอฟต์แวร์", "ฮาร์ดแวร์", "ระบบ", "เครือข่าย",
# Education terms
"โรงเรียน", "มหาวิทยาลัย", "นักเรียน", "นักศึกษา", "ครู", "อาจารย์",
"เรียน", "สอน", "สอบ", "เกรด", "วิชา", "ห้องเรียน", "ห้องสมุด",
# Business terms
"บริษัท", "ธุรกิจ", "ลูกค้า", "ขาย", "ซื้อ", "เงิน", "ราคา",
"ตลาด", "งาน", "เงินเดือน", "สัญญา", "สัญญา", "เอกสาร",
# Health terms
"โรงพยาบาล", "แพทย์", "พยาบาล", "ยา", "อาการ", "ป่วย", "หาย",
"สุขภาพ", "ออกกำลังกาย", "อาหาร", "ดื่ม", "นอน",
# Time expressions
"วันนี้", "เมื่อวาน", "พรุ่งนี้", "เช้า", "บ่าย", "เย็น", "คืน",
"อาทิตย์", "เดือน", "ปี", "ชั่วโมง", "นาที", "วินาที",
# Numbers and quantities
"หนึ่ง", "สอง", "สาม", "สี่", "ห้า", "หก", "เจ็ด", "แปด", "เก้า", "สิบ",
"ร้อย", "พัน", "หมื่น", "แสน", "ล้าน", "หลาย", "ทั้งหมด", "บาง",
# Question words
"ใคร", "อะไร", "ที่ไหน", "เมื่อไหร่", "ทำไม", "อย่างไร", "เท่าไหร่",
# Prepositions and conjunctions
"ใน", "บน", "ใต้", "ข้าง", "หลัง", "หน้า", "ระหว่าง", "กับ",
"จาก", "ถึง", "โดย", "สำหรับ", "เกี่ยวกับ", "เนื่องจาก",
# Adjectives
"ดี", "เลว", "ใหญ่", "เล็ก", "สวย", "งาม", "เร็ว", "ช้า",
"ร้อน", "เย็น", "ง่าย", "ยาก", "แพง", "ถูก", "ใหม่", "เก่า",
# Verbs
"ทำ", "ไป", "มา", "เห็น", "ได้ยิน", "พูด", "เขียน", "อ่าน",
"กิน", "ดื่ม", "นั่ง", "ยืน", "นอน", "วิ่ง", "เดิน", "ขับ",
# Nouns
"บ้าน", "รถ", "แมว", "สุนัข", "คน", "เด็ก", "ผู้ใหญ่", "ผู้หญิง", "ผู้ชาย",
"แม่", "พ่อ", "พี่", "น้อง", "เพื่อน", "ครอบครัว", "เมือง", "ประเทศ",
# Places
"กรุงเทพ", "เชียงใหม่", "ภูเก็ต", "พัทยา", "หัวหิน", "เกาะสมุย",
"ประเทศไทย", "อเมริกา", "ยุโรป", "เอเชีย", "แอฟริกา",
# Food and drinks
"ข้าว", "น้ำ", "กาแฟ", "ชา", "นม", "เนื้อ", "ปลา", "ผัก", "ผลไม้",
"อาหาร", "เครื่องดื่ม", "ร้านอาหาร", "ตลาด", "ซุปเปอร์มาร์เก็ต",
# Technology specific
"แอพพลิเคชัน", "เว็บไซต์", "อีเมล", "โซเชียลมีเดีย", "ยูทูบ",
"เฟซบุ๊ก", "ทวิตเตอร์", "อินสตาแกรม", "ไลน์", "วีแชต",
# AI/ML terms
"โมเดล", "อัลกอริทึม", "ข้อมูล", "การฝึก", "การทดสอบ", "ความแม่นยำ",
"การทำนาย", "การจำแนก", "การถดถอย", "คลัสเตอร์", "นิวรัลเน็ตเวิร์ก"
}
return set(thai_words)
def _longest_matching_segmentation(self, text: str) -> List[str]:
"""Apply longest matching algorithm for Thai word segmentation."""
if not text:
return []
words = []
i = 0
while i < len(text):
# Try longest possible match first
found = False
for length in range(min(self.max_word_length, len(text) - i), 0, -1):
candidate = text[i:i + length]
if candidate in self.thai_dictionary or candidate in self.vocab:
words.append(candidate)
i += length
found = True
break
if not found:
# No dictionary match, use syllable segmentation
syllable = self._extract_single_syllable(text, i)
if syllable:
words.append(syllable)
i += len(syllable)
else:
# Fallback to single character
words.append(text[i])
i += 1
return words
def _learn_new_words(self, text: str):
"""Learn new words from text and add to vocabulary if they meet criteria."""
if not self.learning_enabled:
return
words = self._extract_words(text)
for word in words:
if len(word.strip()) > 0:
self.word_freq[word] += 1
# Add to vocabulary if frequency meets threshold and vocab not full
if (self.word_freq[word] >= self.min_freq and
word not in self.vocab and
len(self.vocab) < self.vocab_size):
self._add_token(word)
logger.debug(f"Learned new word: '{word}' (freq: {self.word_freq[word]})")
def _extract_words(self, text: str) -> List[str]:
"""Extract words from text, handling Thai word boundaries with enhanced PyThaiNLP."""
# For Thai text, use enhanced pythainlp integration
if self._is_thai_text(text):
if PYTHAINLP_AVAILABLE:
try:
words = word_tokenize(text, engine="newmm")
# Enhanced filtering and processing
filtered_words = []
for w in words:
w = w.strip()
if len(w) >= 2 and w and not w.isdigit():
# Add to vocabulary immediately for better tokenization
if self.learning_enabled and w not in self.vocab:
self._add_token_immediately(w)
filtered_words.append(w)
return filtered_words
except Exception as e:
logger.warning(f"PyThaiNLP word extraction failed: {e}. Using enhanced fallback.")
return self._enhanced_pythainlp_fallback(text)
else:
# For non-Thai text, use regex-based extraction
words = re.findall(r'\b\w+\b', text)
filtered_words = []
for word in words:
word = word.strip()
if len(word) >= 2 and not word.isdigit():
filtered_words.append(word)
return filtered_words
def _extract_thai_words(self, text: str) -> List[str]:
"""Extract Thai words using syllable and linguistic patterns."""
words = []
# Split by spaces first
chunks = text.split()
for chunk in chunks:
chunk = chunk.strip()
if not chunk:
continue
# For short chunks, treat as single words
if len(chunk) <= 4:
if len(chunk) >= 2:
words.append(chunk)
continue
# For longer chunks, try to split into meaningful words
# This is a simplified approach - in practice, you'd want more sophisticated Thai word segmentation
potential_words = []
# Try different split points
for i in range(2, len(chunk) - 1):
if i < len(chunk):
word1 = chunk[:i]
word2 = chunk[i:]
# Check if both parts look like valid Thai words
if (len(word1) >= 2 and len(word2) >= 2 and
self._is_valid_thai_word(word1) and self._is_valid_thai_word(word2)):
potential_words.append((word1, word2))
if potential_words:
# Use the first reasonable split
word1, word2 = potential_words[0]
words.extend([word1, word2])
else:
# If no good split found, keep as single word or split into syllables
syllables = self._extract_syllables(chunk)
words.extend([s for s in syllables if len(s) >= 2])
return words
def _is_valid_thai_word(self, word: str) -> bool:
"""Check if a string looks like a valid Thai word."""
if len(word) < 2:
return False
# Must contain at least one Thai consonant
has_consonant = any(c in self.thai_consonants for c in word)
# Should not be all consonants or all vowels
has_vowel = any(c in (self.thai_vowels + self.thai_tonemarks) for c in word)
return has_consonant and has_vowel
def _add_token(self, token: str):
"""Add a new token to vocabulary with duplicate prevention."""
if token in self.vocab:
return # Already exists
# Use sequential token ID assignment instead of hash-based
if not hasattr(self, 'next_token_id'):
self.next_token_id = len(self.special_tokens)
token_id = self.next_token_id
# Ensure we don't exceed vocab size
if token_id >= self.vocab_size:
logger.warning(f"Cannot add token '{token}': vocab size limit reached ({self.vocab_size})")
return
# Ensure uniqueness (though sequential should prevent this)
while token_id in self.reverse_vocab:
token_id += 1
if token_id >= self.vocab_size:
logger.warning(f"Cannot add token '{token}': no available token IDs")
return
self.vocab[token] = token_id
self.reverse_vocab[token_id] = token
self.next_token_id = token_id + 1
logger.info(f"Added new token: '{token}' -> {token_id}")
def _add_token_immediately(self, token: str):
"""Add token immediately without frequency checking for PyThaiNLP integration."""
if token in self.vocab:
return # Already exists
# Use sequential token ID assignment
if not hasattr(self, 'next_token_id'):
self.next_token_id = len(self.special_tokens)
token_id = self.next_token_id
# Ensure we don't exceed vocab size
if token_id >= self.vocab_size:
return # Silently skip if vocab full
# Ensure uniqueness
while token_id in self.reverse_vocab:
token_id += 1
if token_id >= self.vocab_size:
return
self.vocab[token] = token_id
self.reverse_vocab[token_id] = token
self.next_token_id = token_id + 1
logger.debug(f"Immediately added token: '{token}' -> {token_id}")
def _enhanced_pythainlp_fallback(self, text: str) -> List[str]:
"""Enhanced fallback segmentation when PyThaiNLP is not available."""
words = []
# Split by spaces first
chunks = text.split()
for chunk in chunks:
chunk = chunk.strip()
if not chunk:
continue
# For short chunks, treat as single words
if len(chunk) <= 4:
if len(chunk) >= 2:
words.append(chunk)
continue
# Try dictionary-based segmentation first
dict_words = self._dictionary_based_segmentation(chunk)
if dict_words:
words.extend(dict_words)
else:
# Fallback to syllable segmentation
syllables = self._extract_syllables(chunk)
words.extend([s for s in syllables if len(s) >= 2])
return words
def _dictionary_based_segmentation(self, text: str) -> List[str]:
"""Segment text using dictionary lookup."""
if not text:
return []
words = []
i = 0
while i < len(text):
# Try longest possible match from dictionary
found = False
for length in range(min(len(text) - i, 10), 0, -1): # Max word length 10
candidate = text[i:i + length]
if candidate in self.thai_dictionary or candidate in self.vocab:
words.append(candidate)
i += length
found = True
break
if not found:
# No dictionary match, take next character
words.append(text[i])
i += 1
return words
def _multi_engine_segmentation(self, text: str, domain: str = "general") -> List[str]:
"""Use multiple PyThaiNLP engines and select the best result."""
if not PYTHAINLP_AVAILABLE:
return self._ultra_enhanced_fallback(text, domain)
best_words = []
best_score = 0.0
# Try different engines
for engine in self.pythainlp_engines:
try:
words = word_tokenize(text, engine=engine)
score = self._evaluate_segmentation_quality(words, text, domain)
if score > best_score:
best_score = score
best_words = words
logger.debug(f"Better segmentation found with {engine}: score {score:.2f}")
except Exception as e:
logger.debug(f"Engine {engine} failed: {e}")
continue
# If no engine worked well, use fallback
if not best_words or best_score < 0.5:
logger.debug("Using fallback segmentation")
best_words = self._ultra_enhanced_fallback(text, domain)
return best_words
def _context_aware_postprocessing(self, words: List[str], original_text: str) -> List[str]:
"""Apply context-aware post-processing to improve segmentation."""
if not words:
return words
processed_words = []
for i, word in enumerate(words):
# Check for context patterns
if word in self.context_patterns.get("question", []):
# Ensure question words are kept together
processed_words.append(word)
elif word in self.context_patterns.get("polite", []):
# Polite expressions should be preserved
processed_words.append(word)
elif word in self.context_patterns.get("time", []):
# Time expressions should be kept intact
processed_words.append(word)
else:
# Check if word should be split further based on context
context_split = self._context_based_split(word, i, words)
if context_split:
processed_words.extend(context_split)
else:
processed_words.append(word)
return processed_words
def _domain_specific_enhancement(self, words: List[str], domain: str) -> List[str]:
"""Enhance segmentation based on domain-specific knowledge."""
if domain not in self.domain_dictionaries:
return words
domain_dict = self.domain_dictionaries[domain]
enhanced_words = []
for word in words:
# Check if word can be further split using domain knowledge
if word in domain_dict:
enhanced_words.append(word)
else:
# Try to find domain-specific compounds
domain_split = self._find_domain_compounds(word, domain_dict)
if domain_split:
enhanced_words.extend(domain_split)
else:
enhanced_words.append(word)
return enhanced_words
def _assess_segmentation_quality(self, words: List[str], original_text: str) -> float:
"""Assess the quality of segmentation result."""
if not words:
return 0.0
# Basic quality metrics
total_chars = len(original_text.replace(" ", ""))
segmented_chars = sum(len(word) for word in words)
# Character coverage
coverage = segmented_chars / total_chars if total_chars > 0 else 0.0
# Average word length (prefer meaningful words)
avg_word_length = segmented_chars / len(words) if words else 0.0
# Dictionary coverage
dict_coverage = sum(1 for word in words if word in self.thai_dictionary) / len(words)
# Combined quality score
quality_score = (coverage * 0.4) + (min(avg_word_length / 5.0, 1.0) * 0.3) + (dict_coverage * 0.3)
# Update quality metrics
self.segmentation_quality["total_segments"] += len(words)
self.segmentation_quality["correct_segments"] += int(dict_coverage * len(words))
self.segmentation_quality["avg_confidence"] = (
self.segmentation_quality["avg_confidence"] + quality_score
) / 2
return quality_score
def _ultra_enhanced_fallback(self, text: str, domain: str = "general") -> List[str]:
"""Ultra-enhanced fallback when PyThaiNLP is not available."""
words = []
# Split by spaces first
chunks = text.split()
for chunk in chunks:
chunk = chunk.strip()
if not chunk:
continue
# For short chunks, treat as single words
if len(chunk) <= 4:
if len(chunk) >= 2:
words.append(chunk)
continue
# Try domain-specific segmentation first
if domain in self.domain_dictionaries:
domain_words = self._domain_based_segmentation(chunk, self.domain_dictionaries[domain])
if domain_words:
words.extend(domain_words)
continue
# Try dictionary-based segmentation
dict_words = self._dictionary_based_segmentation(chunk)
if dict_words:
words.extend(dict_words)
else:
# Enhanced syllable segmentation
syllables = self._extract_syllables(chunk)
words.extend([s for s in syllables if len(s) >= 2])
return words
def _ultra_intelligent_segmentation(self, word: str, domain: str = "general") -> List[str]:
"""Ultra-intelligent segmentation for unknown words."""
if not word:
return []
# First, try to add the whole word if it's reasonable
if len(word) <= 10 and self.learning_enabled: # Allow longer words
self._add_token_immediately(word)
return [word]
# Try domain-specific segmentation
if domain in self.domain_dictionaries:
domain_segments = self._domain_based_segmentation(word, self.domain_dictionaries[domain])
if domain_segments:
return domain_segments
# Try dictionary lookup for parts
segments = self._dictionary_based_segmentation(word)
if segments and len(segments) > 1:
return segments
# Enhanced syllable segmentation with context
syllables = self._context_aware_syllable_segmentation(word)
if syllables:
return syllables
# Final fallback: character level
return list(word)
def _enhanced_non_thai_tokenization(self, text: str) -> List[str]:
"""Enhanced tokenization for non-Thai text."""
# Use regex to find words, including contractions and hyphenated words
import re
words = re.findall(r'\b\w+(?:[-\']\w+)*\b', text)
filtered_words = []
for word in words:
word = word.strip()
if len(word) >= 2 and not word.isdigit():
filtered_words.append(word)
return filtered_words
def _evaluate_segmentation_quality(self, words: List[str], text: str, domain: str) -> float:
"""Evaluate segmentation quality for multi-engine selection."""
return self._assess_segmentation_quality(words, text)
def _context_based_split(self, word: str, position: int, all_words: List[str]) -> List[str]:
"""Split word based on context."""
# Simple context-based splitting logic
if len(word) > 6:
# Try to split long words at natural boundaries
for i in range(2, len(word) - 1):
if i < len(word):
part1 = word[:i]
part2 = word[i:]
# Check if both parts are meaningful
if (part1 in self.thai_dictionary or len(part1) <= 3) and \
(part2 in self.thai_dictionary or len(part2) <= 3):
return [part1, part2]
return None
def _find_domain_compounds(self, word: str, domain_dict: Set[str]) -> List[str]:
"""Find domain-specific compound words."""
# Simple compound detection
for i in range(2, len(word)):
if i < len(word):
part1 = word[:i]
part2 = word[i:]
if part1 in domain_dict and part2 in domain_dict:
return [part1, part2]
return None
def _domain_based_segmentation(self, text: str, domain_dict: Set[str]) -> List[str]:
"""Segment text using domain-specific dictionary."""
if not text:
return []
words = []
i = 0
while i < len(text):
found = False
# Try longest possible match from domain dictionary
for length in range(min(len(text) - i, 12), 0, -1):
candidate = text[i:i + length]
if candidate in domain_dict:
words.append(candidate)
i += length
found = True
break
if not found:
# No domain match, take next character
words.append(text[i])
i += 1
return words
def _context_aware_syllable_segmentation(self, word: str) -> List[str]:
"""Context-aware syllable segmentation."""
# Enhanced syllable segmentation with Thai linguistic knowledge
syllables = []
i = 0
while i < len(word):
# Try different syllable lengths
for length in range(min(4, len(word) - i), 0, -1):
candidate = word[i:i + length]
# Check if it looks like a valid Thai syllable
if self._is_valid_thai_syllable(candidate):
syllables.append(candidate)
i += length
break
else:
# No valid syllable found, take single character
syllables.append(word[i])
i += 1
return syllables
def _is_valid_thai_syllable(self, syllable: str) -> bool:
"""Check if a string is a valid Thai syllable."""
if len(syllable) < 1 or len(syllable) > 4:
return False
# Must contain at least one Thai character
has_thai = any(c in (self.thai_consonants + self.thai_vowels) for c in syllable)
# Should not be all consonants (unless very short)
if len(syllable) > 2:
has_vowel = any(c in (self.thai_vowels + self.thai_tonemarks) for c in syllable)
return has_thai and has_vowel
else:
return has_thai
def fit(self, texts: List[str], epochs: int = 1):
"""Train the tokenizer on a corpus of texts."""
logger.info(f"Training tokenizer on {len(texts)} texts for {epochs} epochs")
# Pre-process all texts to build word frequency
logger.info("Building word frequency statistics...")
all_words = []
for text in texts:
words = self._extract_words(text)
all_words.extend(words)
# Update word frequencies
for word in all_words:
self.word_freq[word] += 1
# Sort words by frequency for priority learning
sorted_words = sorted(self.word_freq.items(), key=lambda x: x[1], reverse=True)
for epoch in range(epochs):
logger.info(f"Epoch {epoch + 1}/{epochs}")
words_added = 0
for word, freq in sorted_words:
if freq >= self.min_freq and word not in self.vocab:
if len(self.vocab) < self.vocab_size:
self._add_token(word)
words_added += 1
else:
break
if words_added % 100 == 0 and words_added > 0:
logger.info(f"Added {words_added} words to vocabulary")
logger.info(f"Training complete. Vocabulary size: {len(self.vocab)}")
logger.info(f"Total unique words learned: {len(self.word_freq)}")
def _tokenize_single_line(self, text: str, domain: str = "general") -> List[str]:
"""Tokenize a single line of text without newlines."""
tokens = []
# Handle Thai text with ultra-advanced processing
if self._is_thai_text(text):
if PYTHAINLP_AVAILABLE:
# Multi-engine segmentation with quality evaluation
words = self._multi_engine_segmentation(text, domain)
# Context-aware post-processing
words = self._context_aware_postprocessing(words, text)
# Domain-specific enhancement
words = self._domain_specific_enhancement(words, domain)
# Quality assessment
quality_score = self._assess_segmentation_quality(words, text)
logger.debug(f"Segmentation quality: {quality_score:.2f}")
# Immediate vocabulary expansion
if self.learning_enabled:
for word in words:
if len(word.strip()) >= 2 and word not in self.vocab:
self._add_token_immediately(word)
else:
# Enhanced fallback when PyThaiNLP is not available
words = self._ultra_enhanced_fallback(text, domain)
# Process words with advanced logic
for word in words:
word = word.strip()
if not word:
continue
if word in self.vocab:
tokens.append(word)
elif len(word) <= 3:
# Short words: intelligent handling
if self.learning_enabled and len(word) >= 2:
self._add_token_immediately(word)
tokens.append(word)
else:
tokens.extend(list(word))
else:
# Long words: advanced segmentation
segmented = self._ultra_intelligent_segmentation(word, domain)
tokens.extend(segmented)
else:
# Non-Thai text: enhanced word-based tokenization
words = self._enhanced_non_thai_tokenization(text)
for word in words:
if word in self.vocab:
tokens.append(word)
else:
tokens.extend(list(word))
# Cache the result for future use (skip caching for single lines to avoid conflicts)
# if use_cache and self.enable_cache:
# self.tokenization_cache[text] = tokens.copy()
# Learn new words after tokenization if learning is enabled
if self.learning_enabled:
self._learn_new_words(text)
return tokens
def tokenize(self, text: str, domain: str = "general", use_cache: bool = True) -> List[str]:
"""Ultra-advanced tokenization with multi-engine support, context-awareness, and newline handling."""
tokens = []
# Check cache first for performance
if use_cache and self.enable_cache and text in self.tokenization_cache:
self.cache_hits += 1
return self.tokenization_cache[text].copy()
self.cache_misses += 1
# Handle newlines by splitting text and preserving line breaks
if '\n' in text:
lines = text.split('\n')
all_tokens = []
for i, line in enumerate(lines):
if line.strip(): # Only tokenize non-empty lines
line_tokens = self._tokenize_single_line(line, domain)
all_tokens.extend(line_tokens)
# Add newline token between lines (except after the last line)
if i < len(lines) - 1:
all_tokens.append("<newline>")
tokens = all_tokens
else:
tokens = self._tokenize_single_line(text, domain)
# Cache the result for future use
if use_cache and self.enable_cache:
self.tokenization_cache[text] = tokens.copy()
# Learn new words after tokenization if learning is enabled
if self.learning_enabled:
self._learn_new_words(text)
return tokens
def encode(self, text: str) -> List[int]:
"""Convert text to token IDs."""
tokens = self.tokenize(text)
token_ids = []
for token in tokens:
if token in self.vocab:
token_ids.append(self.vocab[token])
else:
token_ids.append(self.special_tokens["<unk>"])
return token_ids
def decode(self, token_ids: List[int]) -> str:
"""Convert token IDs back to text."""
tokens = []
for token_id in token_ids:
if token_id in self.reverse_vocab:
token = self.reverse_vocab[token_id]
if token == "<newline>":
tokens.append("\n")
elif token not in self.special_tokens:
tokens.append(token)
else:
tokens.append("<unk>")
return "".join(tokens)
def save(self, path: str):
"""Save tokenizer state to disk."""
os.makedirs(os.path.dirname(path), exist_ok=True)
state = {
'vocab': self.vocab,
'reverse_vocab': self.reverse_vocab,
'word_freq': dict(self.word_freq),
'syllable_patterns': list(self.syllable_patterns),
'compound_words': list(self.compound_words),
'vocab_size': self.vocab_size,
'min_freq': self.min_freq,
'learning_enabled': self.learning_enabled,
'next_token_id': getattr(self, 'next_token_id', len(self.special_tokens))
}
with open(path, 'wb') as f:
pickle.dump(state, f)
logger.info(f"Tokenizer saved to {path}")
def load(self, path: str):
"""Load tokenizer state from disk."""
if not os.path.exists(path):
logger.warning(f"Tokenizer file {path} not found")
return
with open(path, 'rb') as f:
state = pickle.load(f)
self.vocab = state['vocab']
self.reverse_vocab = state['reverse_vocab']
self.word_freq = Counter(state['word_freq'])
self.syllable_patterns = set(state['syllable_patterns'])
self.compound_words = set(state['compound_words'])
self.vocab_size = state['vocab_size']
self.min_freq = state['min_freq']
self.learning_enabled = state['learning_enabled']
self.next_token_id = state.get('next_token_id', len(self.special_tokens))
logger.info(f"Tokenizer loaded from {path}")
def get_vocab_size(self) -> int:
"""Get current vocabulary size."""
return len(self.vocab)
def get_stats(self) -> Dict:
"""Get comprehensive tokenizer statistics."""
cache_hit_rate = 0.0
if self.cache_hits + self.cache_misses > 0:
cache_hit_rate = self.cache_hits / (self.cache_hits + self.cache_misses)
return {
'vocab_size': len(self.vocab),
'total_words_learned': len(self.word_freq),
'most_common_words': self.word_freq.most_common(10),
'learning_enabled': self.learning_enabled,
'special_tokens': list(self.special_tokens.keys()),
'pythainlp_available': PYTHAINLP_AVAILABLE,
'thai_dictionary_size': len(self.thai_dictionary) if hasattr(self, 'thai_dictionary') else 0,
'cache_enabled': self.enable_cache,
'cache_hit_rate': cache_hit_rate,
'cache_hits': self.cache_hits,
'cache_misses': self.cache_misses,
'current_engine': self.current_engine,
'pythainlp_engines': self.pythainlp_engines,
'domain_dictionaries': list(self.domain_dictionaries.keys()),
'segmentation_quality': self.segmentation_quality,
'context_patterns': list(self.context_patterns.keys())
}
def enable_learning(self):
"""Enable continuous learning mode."""
self.learning_enabled = True
logger.info("Continuous learning enabled")
def disable_learning(self):
"""Disable continuous learning mode."""
self.learning_enabled = False
logger.info("Continuous learning disabled")
# Utility functions for HF integration
def create_hf_tokenizer_files(tokenizer: AdvancedThaiTokenizer, output_dir: str):
"""Create Hugging Face compatible tokenizer files."""
os.makedirs(output_dir, exist_ok=True)
# Create tokenizer.json (simplified BPE-like structure)
tokenizer_json = {
"version": "1.0",
"truncation": None,
"padding": None,
"added_tokens": [
{
"id": tid,
"content": token,
"single_word": False,
"lstrip": False,
"rstrip": False,
"normalized": False,
"special": token in ["<pad>", "<bos>", "<eos>", "<unk>", "<mask>", "<newline>"]
}
for token, tid in tokenizer.vocab.items()
],
"normalizer": None,
"pre_tokenizer": None,
"post_processor": None,
"decoder": None,
"model": {
"type": "BPE",
"vocab": tokenizer.vocab,
"merges": [] # Simplified - no merges for basic implementation
}
}
with open(os.path.join(output_dir, "tokenizer.json"), 'w', encoding='utf-8') as f:
json.dump(tokenizer_json, f, ensure_ascii=False, indent=2)
# Update tokenizer_config.json
tokenizer_config = {
"add_bos_token": True,
"add_eos_token": False,
"bos_token": "<bos>",
"eos_token": "<eos>",
"pad_token": "<pad>",
"unk_token": "<unk>",
"clean_up_tokenization_spaces": False,
"legacy": True,
"model_max_length": 2048,
"tokenizer_class": "PreTrainedTokenizerFast",
"vocab_size": len(tokenizer.vocab),
"use_default_system_prompt": False
}
with open(os.path.join(output_dir, "tokenizer_config.json"), 'w', encoding='utf-8') as f:
json.dump(tokenizer_config, f, ensure_ascii=False, indent=2)
# Update special_tokens_map.json
special_tokens_map = {
"bos_token": "<bos>",
"eos_token": "<eos>",
"pad_token": "<pad>",
"unk_token": "<unk>"
}
with open(os.path.join(output_dir, "special_tokens_map.json"), 'w', encoding='utf-8') as f:
json.dump(special_tokens_map, f, ensure_ascii=False, indent=2)
logger.info(f"Hugging Face tokenizer files created in {output_dir}")
if __name__ == "__main__":
# Example usage
tokenizer = AdvancedThaiTokenizer(vocab_size=50000)
# Sample Thai texts for training (expanded corpus)
sample_texts = [
"สวัสดีครับ วันนี้อากาศดีมากเลย",
"ฉันชอบกินข้าวมันไก่ เพราะอร่อยมาก",
"การเรียนภาษาไทยเป็นเรื่องที่น่าสนใจ",
"ปัญญาประดิษฐ์จะเปลี่ยนโลกใบนี้ไปตลอดกาล",
"เทคโนโลยีสมัยใหม่ช่วยให้ชีวิตง่ายขึ้นมาก",
"ประเทศไทยเป็นประเทศที่มีวัฒนธรรมที่หลากหลาย",
"การพัฒนาประเทศต้องอาศัยการศึกษาที่ดี",
"นักเรียนควรมีความรู้ทางวิทยาศาสตร์และเทคโนโลยี",
"การใช้ภาษาไทยในการสื่อสารเป็นสิ่งสำคัญ",
"เศรษฐกิจไทยมีการเติบโตอย่างต่อเนื่อง",
"การท่องเที่ยวเป็นอุตสาหกรรมสำคัญของไทย",
"วัฒนธรรมไทยมีเอกลักษณ์เฉพาะตัว",
"การอนุรักษ์สิ่งแวดล้อมเป็นหน้าที่ของทุกคน",
"การศึกษาเป็นรากฐานสำคัญของการพัฒนา",
"นวัตกรรมและเทคโนโลยีเป็นกุญแจสู่ความสำเร็จ",
"การทำงานเป็นทีมช่วยให้บรรลุเป้าหมายได้",
"ความซื่อสัตย์และความรับผิดชอบเป็นคุณธรรมสำคัญ",
"การใช้เวลาว่างให้เกิดประโยชน์เป็นสิ่งที่ดี",
"การออกกำลังกายช่วยให้สุขภาพแข็งแรง",
"การอ่านหนังสือเพิ่มพูนความรู้และปัญญา"
]
# Train tokenizer
tokenizer.fit(sample_texts, epochs=2)
# Test tokenization
test_text = "สวัสดีครับ ผมชอบเรียนภาษาไทย"
tokens = tokenizer.tokenize(test_text)
token_ids = tokenizer.encode(test_text)
decoded = tokenizer.decode(token_ids)
print(f"Original: {test_text}")
print(f"Tokens: {tokens}")
print(f"Token IDs: {token_ids}")
print(f"Decoded: {decoded}")
print(f"Vocab size: {tokenizer.get_vocab_size()}")
print(f"Stats: {tokenizer.get_stats()}")
# Save tokenizer
tokenizer.save("modern-thai-gpt-hf/advanced_tokenizer.pkl")
# Create HF compatible files
create_hf_tokenizer_files(tokenizer, "modern-thai-gpt-hf/")