Upload cleaner.py with huggingface_hub
Browse files- cleaner.py +581 -0
cleaner.py
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| 1 |
+
"""Text cleaning pipeline for preparing training data."""
|
| 2 |
+
|
| 3 |
+
import logging
|
| 4 |
+
import re
|
| 5 |
+
import unicodedata
|
| 6 |
+
|
| 7 |
+
logger = logging.getLogger(__name__)
|
| 8 |
+
|
| 9 |
+
|
| 10 |
+
class TextCleaner:
|
| 11 |
+
"""Cleans raw text for character-level language model training."""
|
| 12 |
+
|
| 13 |
+
# Project Gutenberg header/footer patterns
|
| 14 |
+
GUTENBERG_START = re.compile(
|
| 15 |
+
r"\*\*\*\s*START OF (?:THE |THIS )?PROJECT GUTENBERG.*?\*\*\*",
|
| 16 |
+
re.IGNORECASE,
|
| 17 |
+
)
|
| 18 |
+
GUTENBERG_END = re.compile(
|
| 19 |
+
r"\*\*\*\s*END OF (?:THE |THIS )?PROJECT GUTENBERG.*?\*\*\*",
|
| 20 |
+
re.IGNORECASE,
|
| 21 |
+
)
|
| 22 |
+
# Fallback for Gutenberg files that lack *** markers
|
| 23 |
+
GUTENBERG_END_PLAIN = re.compile(
|
| 24 |
+
r"^End of (?:the )?Project Gutenberg",
|
| 25 |
+
re.IGNORECASE | re.MULTILINE,
|
| 26 |
+
)
|
| 27 |
+
|
| 28 |
+
# MIT Internet Classics Archive patterns
|
| 29 |
+
MIT_HEADER = re.compile(
|
| 30 |
+
r"provided by the internet classics archive\..*?-{6,}",
|
| 31 |
+
re.IGNORECASE | re.DOTALL,
|
| 32 |
+
)
|
| 33 |
+
MIT_FOOTER = re.compile(
|
| 34 |
+
r"the internet classics archive\b[^\n]*(?:web atomics)?[^\n]*",
|
| 35 |
+
re.IGNORECASE,
|
| 36 |
+
)
|
| 37 |
+
MIT_DASH_LINE = re.compile(r"-{6,}")
|
| 38 |
+
|
| 39 |
+
# Internet Archive patterns
|
| 40 |
+
IA_HEADER = re.compile(
|
| 41 |
+
r"(?:Digitized by|Book digitized by|Original from|Uploaded by)"
|
| 42 |
+
r"[^\n]*",
|
| 43 |
+
re.IGNORECASE,
|
| 44 |
+
)
|
| 45 |
+
IA_GOOGLE_MARKER = re.compile(
|
| 46 |
+
r"(?:Generated (?:by|from)|Google-digitized|"
|
| 47 |
+
r"This is a digital copy of a book)[^\n]*",
|
| 48 |
+
re.IGNORECASE,
|
| 49 |
+
)
|
| 50 |
+
|
| 51 |
+
# Roman numeral pattern — matches standalone uppercase Roman numerals (2+ chars)
|
| 52 |
+
ROMAN_NUMERAL = re.compile(
|
| 53 |
+
r"\b(M{0,3}(?:CM|CD|D?C{0,3})(?:XC|XL|L?X{0,3})(?:IX|IV|V?I{0,3}))\b"
|
| 54 |
+
)
|
| 55 |
+
# Context words that allow single "I" to be treated as Roman numeral 1
|
| 56 |
+
ROMAN_CONTEXT = re.compile(
|
| 57 |
+
r"\b(?:book|chapter|prop|proposition|part|vol|volume|no|number|"
|
| 58 |
+
r"section|act|scene|lib|epistle|ode|psalm|canon|lemma|corollary|"
|
| 59 |
+
r"cor|def|definition|axiom|postulate)\b",
|
| 60 |
+
re.IGNORECASE,
|
| 61 |
+
)
|
| 62 |
+
|
| 63 |
+
# Roman numeral value map
|
| 64 |
+
ROMAN_VALUES = {"I": 1, "V": 5, "X": 10, "L": 50, "C": 100, "D": 500, "M": 1000}
|
| 65 |
+
|
| 66 |
+
# Non-body section headers (for aggressive stripping)
|
| 67 |
+
# NOTE: "INTRODUCTION" is deliberately excluded — it is often the author's own text
|
| 68 |
+
FRONT_MATTER_HEADERS = re.compile(
|
| 69 |
+
r"^\s*(?:PREFACE|FOREWORD|FORWARD|EDITOR[\u2019']?S?\s+NOTE|"
|
| 70 |
+
r"TRANSLATOR[\u2019']?S?\s+NOTE|PREFATORY\s+NOTE|PRELIMINARY\s+NOTE|"
|
| 71 |
+
r"BIOGRAPHICAL\s+(?:NOTE|SKETCH)|ADVERTISEMENT|DEDICAT(?:ION|ED\s+TO)|"
|
| 72 |
+
r"TO\s+THE\s+READER|NOTE\s+ON\s+(?:THE\s+)?TEXT|ABOUT\s+THIS\s+EDITION|"
|
| 73 |
+
r"CHRONOLOG(?:Y|ICAL))[.:\-\u2014]*\s*$",
|
| 74 |
+
re.IGNORECASE | re.MULTILINE,
|
| 75 |
+
)
|
| 76 |
+
BACK_MATTER_HEADERS = re.compile(
|
| 77 |
+
r"^\s*(?:APPENDIX|ADDEND(?:UM|A)|INDEX|GLOSSARY|BIBLIOGRAPHY|"
|
| 78 |
+
r"WORKS?\s+CITED|REFERENCES|ENDNOTES|FOOTNOTES|"
|
| 79 |
+
r"ACKNOWLEDG(?:E?MENTS?)|CREDITS|COLOPHON|ERRATA|"
|
| 80 |
+
r"TRANSCRIBER[\u2019']?S?\s+NOTES?|"
|
| 81 |
+
r"TYPOGRAPHICAL\s+ERRORS?\s+CORRECTED|"
|
| 82 |
+
r"LIST\s+OF\s+(?:ILLUSTRATIONS|FIGURES|PLATES))[.:\-\u2014]*\s*$",
|
| 83 |
+
re.IGNORECASE | re.MULTILINE,
|
| 84 |
+
)
|
| 85 |
+
TOC_HEADER = re.compile(
|
| 86 |
+
r"^\s*(?:TABLE\s+OF\s+)?CONTENTS?[.:\-\u2014]*\s*$",
|
| 87 |
+
re.IGNORECASE | re.MULTILINE,
|
| 88 |
+
)
|
| 89 |
+
|
| 90 |
+
# Production/publisher patterns (for front matter cleanup)
|
| 91 |
+
PRODUCTION_PATTERNS = [
|
| 92 |
+
re.compile(p, re.IGNORECASE) for p in [
|
| 93 |
+
r"(?:produced|prepared|transcribed|digitized|scanned)\s+(?:by|for|at)",
|
| 94 |
+
r"production\s+note",
|
| 95 |
+
r"transcriber[\u2019']?s?\s+note",
|
| 96 |
+
r"scanner[\u2019']?s?\s+note",
|
| 97 |
+
r"cornell\s+university\s+library",
|
| 98 |
+
r"(?:published|printed)\s+(?:by|for|at|in)",
|
| 99 |
+
r"(?:first|second|third|\d+(?:st|nd|rd|th))\s+edition",
|
| 100 |
+
r"price\s+\w+[sd]\.",
|
| 101 |
+
r"(?:cloth|paper|hardcover|paperback|octavo|quarto)",
|
| 102 |
+
r"\bisbn\b",
|
| 103 |
+
r"all\s+rights?\s+reserved",
|
| 104 |
+
r"(?:copyright|copr\.?)\s*(?:\(c\)|\xa9|\d)",
|
| 105 |
+
r"press\s+of\b",
|
| 106 |
+
r"university\s+press",
|
| 107 |
+
]
|
| 108 |
+
]
|
| 109 |
+
|
| 110 |
+
# Transcriber correction notes (back matter)
|
| 111 |
+
TRANSCRIBER_CORRECTION = re.compile(
|
| 112 |
+
r"^p\.\s*(?:\d+|\?\??|\.)\s*[.,]?\s*(?:sqq\.|in\s|the\s|as\s|heading|"
|
| 113 |
+
r"reference|prop|from\s|then\s|these\s|def\.|"
|
| 114 |
+
r"twenty|thirty|forty|fifty|sixty|seventy|eighty|ninety|"
|
| 115 |
+
r"one\s|two\s|three|four|five|six\s|seven|eight|nine|"
|
| 116 |
+
# Match quoted corrections
|
| 117 |
+
r'["\u201c])',
|
| 118 |
+
re.IGNORECASE,
|
| 119 |
+
)
|
| 120 |
+
|
| 121 |
+
# Separator/decoration lines
|
| 122 |
+
SEPARATOR_LINE = re.compile(r"^[\s.*_=~\-#]+$")
|
| 123 |
+
|
| 124 |
+
# Number words for 0-19 and tens
|
| 125 |
+
ONES = [
|
| 126 |
+
"zero", "one", "two", "three", "four", "five", "six", "seven",
|
| 127 |
+
"eight", "nine", "ten", "eleven", "twelve", "thirteen", "fourteen",
|
| 128 |
+
"fifteen", "sixteen", "seventeen", "eighteen", "nineteen",
|
| 129 |
+
]
|
| 130 |
+
TENS = [
|
| 131 |
+
"", "", "twenty", "thirty", "forty", "fifty", "sixty", "seventy",
|
| 132 |
+
"eighty", "ninety",
|
| 133 |
+
]
|
| 134 |
+
|
| 135 |
+
def __init__(self, config: dict):
|
| 136 |
+
self.lowercase = config.get("lowercase", True)
|
| 137 |
+
self.strip_gutenberg = config.get("strip_gutenberg", True)
|
| 138 |
+
self.strip_mit_classics = config.get("strip_mit_classics", True)
|
| 139 |
+
self.strip_internet_archive = config.get("strip_internet_archive", True)
|
| 140 |
+
self.normalize_unicode = config.get("normalize_unicode", True)
|
| 141 |
+
self.convert_numerals = config.get("convert_numerals", False)
|
| 142 |
+
self.convert_roman_numerals = config.get("convert_roman_numerals", False)
|
| 143 |
+
self.strip_non_body = config.get("strip_non_body", True)
|
| 144 |
+
self.min_line_length = config.get("min_line_length", 20)
|
| 145 |
+
self.remove_urls = config.get("remove_urls", True)
|
| 146 |
+
self.collapse_whitespace = config.get("collapse_whitespace", True)
|
| 147 |
+
self.allowed_chars = config.get("allowed_chars", r"a-z0-9 .,;:!?'\"\-\(\)")
|
| 148 |
+
|
| 149 |
+
def clean(self, text: str) -> str:
|
| 150 |
+
"""Run all cleaning stages on the input text."""
|
| 151 |
+
if not text.strip():
|
| 152 |
+
return ""
|
| 153 |
+
|
| 154 |
+
# Stage 1: Strip source-specific boilerplate
|
| 155 |
+
if self.strip_gutenberg:
|
| 156 |
+
text = self._strip_gutenberg(text)
|
| 157 |
+
|
| 158 |
+
if self.strip_mit_classics:
|
| 159 |
+
text = self._strip_mit_classics(text)
|
| 160 |
+
|
| 161 |
+
if self.strip_internet_archive:
|
| 162 |
+
text = self._strip_internet_archive(text)
|
| 163 |
+
|
| 164 |
+
# Stage 2: Strip non-body content (before any text transforms)
|
| 165 |
+
if self.strip_non_body:
|
| 166 |
+
text = self._strip_non_body(text)
|
| 167 |
+
|
| 168 |
+
# Stage 3: Normalize unicode
|
| 169 |
+
if self.normalize_unicode:
|
| 170 |
+
text = self._normalize_unicode(text)
|
| 171 |
+
|
| 172 |
+
if self.remove_urls:
|
| 173 |
+
text = self._remove_urls(text)
|
| 174 |
+
|
| 175 |
+
# Stage 4: Convert Roman numerals (BEFORE lowercase — needs uppercase)
|
| 176 |
+
if self.convert_roman_numerals:
|
| 177 |
+
text = self._convert_roman_numerals(text)
|
| 178 |
+
|
| 179 |
+
# Stage 5: Lowercase
|
| 180 |
+
if self.lowercase:
|
| 181 |
+
text = text.lower()
|
| 182 |
+
|
| 183 |
+
# Stage 6: Convert Arabic numerals
|
| 184 |
+
if self.convert_numerals:
|
| 185 |
+
text = self._convert_numerals(text)
|
| 186 |
+
|
| 187 |
+
# Stage 7: Character filtering
|
| 188 |
+
text = self._clean_chars(text)
|
| 189 |
+
|
| 190 |
+
# Stage 8: Collapse whitespace
|
| 191 |
+
if self.collapse_whitespace:
|
| 192 |
+
text = self._collapse_whitespace(text)
|
| 193 |
+
|
| 194 |
+
return text.strip()
|
| 195 |
+
|
| 196 |
+
# ------------------------------------------------------------------
|
| 197 |
+
# Source boilerplate stripping
|
| 198 |
+
# ------------------------------------------------------------------
|
| 199 |
+
|
| 200 |
+
def _strip_gutenberg(self, text: str) -> str:
|
| 201 |
+
"""Remove Project Gutenberg headers and footers."""
|
| 202 |
+
# Strip footer first (before positions shift)
|
| 203 |
+
end_match = self.GUTENBERG_END.search(text)
|
| 204 |
+
if not end_match:
|
| 205 |
+
end_match = self.GUTENBERG_END_PLAIN.search(text)
|
| 206 |
+
if end_match:
|
| 207 |
+
text = text[:end_match.start()]
|
| 208 |
+
|
| 209 |
+
# Strip header
|
| 210 |
+
start_match = self.GUTENBERG_START.search(text)
|
| 211 |
+
if start_match:
|
| 212 |
+
text = text[start_match.end():]
|
| 213 |
+
|
| 214 |
+
# Also strip common Gutenberg preamble lines
|
| 215 |
+
lines = text.split("\n")
|
| 216 |
+
cleaned = []
|
| 217 |
+
skip = True if start_match is None else False
|
| 218 |
+
for line in lines:
|
| 219 |
+
stripped = line.strip()
|
| 220 |
+
if skip and stripped.startswith(("Title:", "Author:", "Release Date:",
|
| 221 |
+
"Language:", "Character set",
|
| 222 |
+
"Produced by", "Updated editions")):
|
| 223 |
+
continue
|
| 224 |
+
if skip and not stripped:
|
| 225 |
+
continue
|
| 226 |
+
skip = False
|
| 227 |
+
cleaned.append(line)
|
| 228 |
+
|
| 229 |
+
return "\n".join(cleaned)
|
| 230 |
+
|
| 231 |
+
def _strip_mit_classics(self, text: str) -> str:
|
| 232 |
+
"""Remove MIT Internet Classics Archive headers, footers, and section dividers."""
|
| 233 |
+
text = self.MIT_HEADER.sub("", text)
|
| 234 |
+
text = self.MIT_FOOTER.sub("", text)
|
| 235 |
+
text = self.MIT_DASH_LINE.sub("", text)
|
| 236 |
+
return text
|
| 237 |
+
|
| 238 |
+
def _strip_internet_archive(self, text: str) -> str:
|
| 239 |
+
"""Remove Internet Archive / Google Books digitization boilerplate."""
|
| 240 |
+
text = self.IA_HEADER.sub("", text)
|
| 241 |
+
text = self.IA_GOOGLE_MARKER.sub("", text)
|
| 242 |
+
return text
|
| 243 |
+
|
| 244 |
+
# ------------------------------------------------------------------
|
| 245 |
+
# Non-body content stripping (aggressive mode)
|
| 246 |
+
# ------------------------------------------------------------------
|
| 247 |
+
|
| 248 |
+
def _strip_non_body(self, text: str) -> str:
|
| 249 |
+
"""Remove front matter, back matter, and inline non-body content."""
|
| 250 |
+
text = self._strip_front_matter(text)
|
| 251 |
+
text = self._strip_back_matter(text)
|
| 252 |
+
text = self._strip_inline_non_body(text)
|
| 253 |
+
return text
|
| 254 |
+
|
| 255 |
+
def _strip_front_matter(self, text: str) -> str:
|
| 256 |
+
"""Strip front matter: production notes, TOC, preface, etc.
|
| 257 |
+
|
| 258 |
+
Order: (1) strip named sections by header, (2) skip remaining
|
| 259 |
+
non-body paragraphs at the top.
|
| 260 |
+
"""
|
| 261 |
+
# Pass 1: Remove named sections that have clear headers
|
| 262 |
+
text = self._strip_section(text, self.FRONT_MATTER_HEADERS)
|
| 263 |
+
text = self._strip_section(text, self.TOC_HEADER)
|
| 264 |
+
|
| 265 |
+
# Pass 2: Skip non-body paragraphs at the beginning.
|
| 266 |
+
# Body prose = substantial paragraph (>150 chars) with full sentences
|
| 267 |
+
# that does NOT match production/publisher patterns.
|
| 268 |
+
lines = text.split("\n")
|
| 269 |
+
start_idx = 0
|
| 270 |
+
i = 0
|
| 271 |
+
while i < len(lines):
|
| 272 |
+
# Collect next paragraph
|
| 273 |
+
while i < len(lines) and not lines[i].strip():
|
| 274 |
+
i += 1
|
| 275 |
+
para_start = i
|
| 276 |
+
para_lines = []
|
| 277 |
+
while i < len(lines) and lines[i].strip():
|
| 278 |
+
para_lines.append(lines[i].strip())
|
| 279 |
+
i += 1
|
| 280 |
+
|
| 281 |
+
if not para_lines:
|
| 282 |
+
continue
|
| 283 |
+
|
| 284 |
+
para_text = " ".join(para_lines)
|
| 285 |
+
|
| 286 |
+
has_sentences = bool(re.search(r"\.\s+[A-Z]", para_text))
|
| 287 |
+
is_substantial = len(para_text) > 150
|
| 288 |
+
is_production = self._is_production_line(para_text)
|
| 289 |
+
|
| 290 |
+
# Title pages / heading blocks: mostly uppercase letters
|
| 291 |
+
alpha_chars = [c for c in para_text if c.isalpha()]
|
| 292 |
+
is_mostly_uppercase = (
|
| 293 |
+
alpha_chars
|
| 294 |
+
and sum(1 for c in alpha_chars if c.isupper()) / len(alpha_chars) > 0.5
|
| 295 |
+
)
|
| 296 |
+
|
| 297 |
+
# Short average line length suggests a title/heading block
|
| 298 |
+
avg_line_len = sum(len(l) for l in para_lines) / len(para_lines)
|
| 299 |
+
is_short_lines = avg_line_len < 50
|
| 300 |
+
|
| 301 |
+
if (is_substantial and has_sentences
|
| 302 |
+
and not is_production
|
| 303 |
+
and not is_mostly_uppercase
|
| 304 |
+
and not is_short_lines):
|
| 305 |
+
start_idx = para_start
|
| 306 |
+
break
|
| 307 |
+
|
| 308 |
+
# Not body yet — skip it
|
| 309 |
+
start_idx = i
|
| 310 |
+
|
| 311 |
+
return "\n".join(lines[start_idx:])
|
| 312 |
+
|
| 313 |
+
def _strip_back_matter(self, text: str) -> str:
|
| 314 |
+
"""Strip back matter: appendixes, index, transcriber notes, etc."""
|
| 315 |
+
lines = text.split("\n")
|
| 316 |
+
|
| 317 |
+
# Find the first back-matter header and truncate there
|
| 318 |
+
first_back_idx = None
|
| 319 |
+
for i, line in enumerate(lines):
|
| 320 |
+
stripped = line.strip()
|
| 321 |
+
if self.BACK_MATTER_HEADERS.match(stripped):
|
| 322 |
+
first_back_idx = i
|
| 323 |
+
break
|
| 324 |
+
# Also detect "Typographical Errors corrected..." as back matter start
|
| 325 |
+
if re.match(r"Typographical\s+Errors?\b", stripped, re.IGNORECASE):
|
| 326 |
+
first_back_idx = i
|
| 327 |
+
break
|
| 328 |
+
|
| 329 |
+
if first_back_idx is not None:
|
| 330 |
+
lines = lines[:first_back_idx]
|
| 331 |
+
|
| 332 |
+
# Strip trailing transcriber correction notes (working backward)
|
| 333 |
+
while lines:
|
| 334 |
+
stripped = lines[-1].strip()
|
| 335 |
+
if not stripped:
|
| 336 |
+
lines.pop()
|
| 337 |
+
continue
|
| 338 |
+
if self.TRANSCRIBER_CORRECTION.match(stripped):
|
| 339 |
+
lines.pop()
|
| 340 |
+
continue
|
| 341 |
+
if self._is_production_line(stripped):
|
| 342 |
+
lines.pop()
|
| 343 |
+
continue
|
| 344 |
+
break
|
| 345 |
+
|
| 346 |
+
return "\n".join(lines)
|
| 347 |
+
|
| 348 |
+
def _strip_inline_non_body(self, text: str) -> str:
|
| 349 |
+
"""Strip inline non-body markers: separator lines, all-caps headings."""
|
| 350 |
+
lines = text.split("\n")
|
| 351 |
+
cleaned = []
|
| 352 |
+
for line in lines:
|
| 353 |
+
stripped = line.strip()
|
| 354 |
+
|
| 355 |
+
# Remove separator/decoration lines
|
| 356 |
+
if stripped and self.SEPARATOR_LINE.match(stripped):
|
| 357 |
+
continue
|
| 358 |
+
|
| 359 |
+
# Remove short ALL-CAPS lines (likely section headings)
|
| 360 |
+
if stripped and len(stripped) < 80 and stripped == stripped.upper() and stripped.isalpha():
|
| 361 |
+
continue
|
| 362 |
+
|
| 363 |
+
cleaned.append(line)
|
| 364 |
+
|
| 365 |
+
return "\n".join(cleaned)
|
| 366 |
+
|
| 367 |
+
def _strip_section(self, text: str, header_pattern: re.Pattern) -> str:
|
| 368 |
+
"""Remove a section identified by header_pattern until next section boundary."""
|
| 369 |
+
lines = text.split("\n")
|
| 370 |
+
result = []
|
| 371 |
+
skipping = False
|
| 372 |
+
|
| 373 |
+
for i, line in enumerate(lines):
|
| 374 |
+
stripped = line.strip()
|
| 375 |
+
|
| 376 |
+
if header_pattern.match(stripped):
|
| 377 |
+
skipping = True
|
| 378 |
+
continue
|
| 379 |
+
|
| 380 |
+
if skipping:
|
| 381 |
+
# Stop skipping at next section boundary:
|
| 382 |
+
# A substantial non-empty line after a blank line, OR
|
| 383 |
+
# A line that looks like a real body section start
|
| 384 |
+
is_blank = not stripped
|
| 385 |
+
if not is_blank and self._is_section_boundary(stripped, lines, i):
|
| 386 |
+
skipping = False
|
| 387 |
+
result.append(line)
|
| 388 |
+
continue
|
| 389 |
+
|
| 390 |
+
result.append(line)
|
| 391 |
+
|
| 392 |
+
return "\n".join(result)
|
| 393 |
+
|
| 394 |
+
def _is_section_boundary(self, stripped: str, lines: list[str], idx: int) -> bool:
|
| 395 |
+
"""Detect if a line marks the beginning of a new major section.
|
| 396 |
+
|
| 397 |
+
Only returns True for explicit section headers/markers, NOT for
|
| 398 |
+
long body-text lines (which can appear inside prefaces/forewords).
|
| 399 |
+
"""
|
| 400 |
+
# Body-start keywords (these signal real content resuming)
|
| 401 |
+
if re.match(
|
| 402 |
+
r"(?:Book|Chapter|Part|Section|Proposition|Theorem|Definition|"
|
| 403 |
+
r"Axiom|Postulate|Introduction|Definitions|Lemma|Corollary|"
|
| 404 |
+
r"Contents?)\b",
|
| 405 |
+
stripped, re.IGNORECASE,
|
| 406 |
+
):
|
| 407 |
+
return True
|
| 408 |
+
|
| 409 |
+
# Another named section header (front or back matter)
|
| 410 |
+
if self.FRONT_MATTER_HEADERS.match(stripped):
|
| 411 |
+
return True
|
| 412 |
+
if self.BACK_MATTER_HEADERS.match(stripped):
|
| 413 |
+
return True
|
| 414 |
+
if self.TOC_HEADER.match(stripped):
|
| 415 |
+
return True
|
| 416 |
+
|
| 417 |
+
return False
|
| 418 |
+
|
| 419 |
+
def _is_production_line(self, line: str) -> bool:
|
| 420 |
+
"""Check if a line is production/publisher metadata."""
|
| 421 |
+
for pattern in self.PRODUCTION_PATTERNS:
|
| 422 |
+
if pattern.search(line):
|
| 423 |
+
return True
|
| 424 |
+
return False
|
| 425 |
+
|
| 426 |
+
# ------------------------------------------------------------------
|
| 427 |
+
# Unicode normalization
|
| 428 |
+
# ------------------------------------------------------------------
|
| 429 |
+
|
| 430 |
+
def _normalize_unicode(self, text: str) -> str:
|
| 431 |
+
"""Normalize unicode characters to their closest ASCII equivalents."""
|
| 432 |
+
text = unicodedata.normalize("NFKD", text)
|
| 433 |
+
replacements = {
|
| 434 |
+
"\u2018": "'", "\u2019": "'", # smart quotes
|
| 435 |
+
"\u201c": '"', "\u201d": '"',
|
| 436 |
+
"\u2013": "-", "\u2014": "-", # en/em dash
|
| 437 |
+
"\u2026": "...", # ellipsis
|
| 438 |
+
"\u00a0": " ", # non-breaking space
|
| 439 |
+
"\u00b6": "", # pilcrow
|
| 440 |
+
"\u00a7": "", # section sign
|
| 441 |
+
}
|
| 442 |
+
for old, new in replacements.items():
|
| 443 |
+
text = text.replace(old, new)
|
| 444 |
+
|
| 445 |
+
# Strip remaining non-ASCII
|
| 446 |
+
text = text.encode("ascii", errors="ignore").decode("ascii")
|
| 447 |
+
return text
|
| 448 |
+
|
| 449 |
+
def _remove_urls(self, text: str) -> str:
|
| 450 |
+
"""Remove URLs and email addresses."""
|
| 451 |
+
text = re.sub(r"https?://\S+", "", text)
|
| 452 |
+
text = re.sub(r"www\.\S+", "", text)
|
| 453 |
+
text = re.sub(r"\S+@\S+\.\S+", "", text)
|
| 454 |
+
return text
|
| 455 |
+
|
| 456 |
+
# ------------------------------------------------------------------
|
| 457 |
+
# Roman numeral conversion
|
| 458 |
+
# ------------------------------------------------------------------
|
| 459 |
+
|
| 460 |
+
def _roman_to_int(self, s: str) -> int:
|
| 461 |
+
"""Convert a Roman numeral string to an integer."""
|
| 462 |
+
result = 0
|
| 463 |
+
prev = 0
|
| 464 |
+
for char in reversed(s.upper()):
|
| 465 |
+
val = self.ROMAN_VALUES.get(char, 0)
|
| 466 |
+
if val < prev:
|
| 467 |
+
result -= val
|
| 468 |
+
else:
|
| 469 |
+
result += val
|
| 470 |
+
prev = val
|
| 471 |
+
return result
|
| 472 |
+
|
| 473 |
+
def _is_valid_roman(self, s: str) -> bool:
|
| 474 |
+
"""Check if a string is a valid Roman numeral (not just random letters)."""
|
| 475 |
+
if not s:
|
| 476 |
+
return False
|
| 477 |
+
# Must only contain valid Roman numeral characters
|
| 478 |
+
if not all(c in "IVXLCDM" for c in s.upper()):
|
| 479 |
+
return False
|
| 480 |
+
# Must convert to a positive number
|
| 481 |
+
val = self._roman_to_int(s)
|
| 482 |
+
return val > 0
|
| 483 |
+
|
| 484 |
+
def _convert_roman_numerals(self, text: str) -> str:
|
| 485 |
+
"""Convert Roman numerals to English words.
|
| 486 |
+
|
| 487 |
+
Handles multi-character Roman numerals (II, IV, XIV, etc.) directly.
|
| 488 |
+
Single 'I' is only converted when preceded by a context word.
|
| 489 |
+
"""
|
| 490 |
+
def replace_roman(m):
|
| 491 |
+
numeral = m.group(1)
|
| 492 |
+
# Skip single-char matches that aren't clearly Roman numerals
|
| 493 |
+
if len(numeral) == 1:
|
| 494 |
+
# Single 'I' — only convert after context words
|
| 495 |
+
if numeral.upper() == "I":
|
| 496 |
+
# Check the text before this match for context words
|
| 497 |
+
before = text[max(0, m.start() - 30):m.start()]
|
| 498 |
+
if not self.ROMAN_CONTEXT.search(before):
|
| 499 |
+
return m.group(0)
|
| 500 |
+
else:
|
| 501 |
+
# Single V, X, L, C, D, M — convert them
|
| 502 |
+
pass
|
| 503 |
+
|
| 504 |
+
if not self._is_valid_roman(numeral):
|
| 505 |
+
return m.group(0)
|
| 506 |
+
|
| 507 |
+
val = self._roman_to_int(numeral)
|
| 508 |
+
return self._number_to_words(val)
|
| 509 |
+
|
| 510 |
+
return self.ROMAN_NUMERAL.sub(replace_roman, text)
|
| 511 |
+
|
| 512 |
+
# ------------------------------------------------------------------
|
| 513 |
+
# Arabic numeral conversion
|
| 514 |
+
# ------------------------------------------------------------------
|
| 515 |
+
|
| 516 |
+
def _number_to_words(self, n: int) -> str:
|
| 517 |
+
"""Convert an integer to English words."""
|
| 518 |
+
if n < 0:
|
| 519 |
+
return "negative " + self._number_to_words(-n)
|
| 520 |
+
if n == 0:
|
| 521 |
+
return self.ONES[0]
|
| 522 |
+
if n < 20:
|
| 523 |
+
return self.ONES[n]
|
| 524 |
+
if n < 100:
|
| 525 |
+
tens, ones = divmod(n, 10)
|
| 526 |
+
return self.TENS[tens] + (" " + self.ONES[ones] if ones else "")
|
| 527 |
+
if n < 1000:
|
| 528 |
+
hundreds, remainder = divmod(n, 100)
|
| 529 |
+
result = self.ONES[hundreds] + " hundred"
|
| 530 |
+
if remainder:
|
| 531 |
+
result += " " + self._number_to_words(remainder)
|
| 532 |
+
return result
|
| 533 |
+
if n < 1000000:
|
| 534 |
+
thousands, remainder = divmod(n, 1000)
|
| 535 |
+
result = self._number_to_words(thousands) + " thousand"
|
| 536 |
+
if remainder:
|
| 537 |
+
result += " " + self._number_to_words(remainder)
|
| 538 |
+
return result
|
| 539 |
+
return str(n)
|
| 540 |
+
|
| 541 |
+
def _convert_numerals(self, text: str) -> str:
|
| 542 |
+
"""Replace standalone digit sequences with their English word equivalents.
|
| 543 |
+
|
| 544 |
+
Only converts digit groups that are standalone words (surrounded by
|
| 545 |
+
whitespace or punctuation), preventing garbled output from codes
|
| 546 |
+
like Z39.48-1984.
|
| 547 |
+
"""
|
| 548 |
+
def replace_match(m):
|
| 549 |
+
# Ensure digits are not part of a larger alphanumeric token
|
| 550 |
+
start, end = m.start(), m.end()
|
| 551 |
+
if start > 0 and text[start - 1].isalnum():
|
| 552 |
+
return m.group()
|
| 553 |
+
if end < len(text) and text[end].isalnum():
|
| 554 |
+
return m.group()
|
| 555 |
+
try:
|
| 556 |
+
n = int(m.group())
|
| 557 |
+
if n < 1000000:
|
| 558 |
+
return self._number_to_words(n)
|
| 559 |
+
except ValueError:
|
| 560 |
+
pass
|
| 561 |
+
return m.group()
|
| 562 |
+
return re.sub(r"\d+", replace_match, text)
|
| 563 |
+
|
| 564 |
+
# ------------------------------------------------------------------
|
| 565 |
+
# Character filtering and whitespace
|
| 566 |
+
# ------------------------------------------------------------------
|
| 567 |
+
|
| 568 |
+
def _clean_chars(self, text: str) -> str:
|
| 569 |
+
"""Remove characters not in the allowed set."""
|
| 570 |
+
pattern = f"[^{self.allowed_chars}\n]"
|
| 571 |
+
text = re.sub(pattern, " ", text)
|
| 572 |
+
# Remove lines that are only dots and/or spaces (separator lines)
|
| 573 |
+
text = re.sub(r"^[. ]+$", "", text, flags=re.MULTILINE)
|
| 574 |
+
return text
|
| 575 |
+
|
| 576 |
+
def _collapse_whitespace(self, text: str) -> str:
|
| 577 |
+
"""Collapse multiple spaces/newlines into single spaces."""
|
| 578 |
+
text = re.sub(r"\n{3,}", "\n\n", text)
|
| 579 |
+
text = re.sub(r" {2,}", " ", text)
|
| 580 |
+
text = re.sub(r" *\n *", "\n", text)
|
| 581 |
+
return text
|