| | from functools import lru_cache |
| | from logging import getLogger |
| | from typing import List, Optional |
| |
|
| | from .constant import ( |
| | COMMON_SAFE_ASCII_CHARACTERS, |
| | TRACE, |
| | UNICODE_SECONDARY_RANGE_KEYWORD, |
| | ) |
| | from .utils import ( |
| | is_accentuated, |
| | is_arabic, |
| | is_arabic_isolated_form, |
| | is_case_variable, |
| | is_cjk, |
| | is_emoticon, |
| | is_hangul, |
| | is_hiragana, |
| | is_katakana, |
| | is_latin, |
| | is_punctuation, |
| | is_separator, |
| | is_symbol, |
| | is_thai, |
| | is_unprintable, |
| | remove_accent, |
| | unicode_range, |
| | ) |
| |
|
| |
|
| | class MessDetectorPlugin: |
| | """ |
| | Base abstract class used for mess detection plugins. |
| | All detectors MUST extend and implement given methods. |
| | """ |
| |
|
| | def eligible(self, character: str) -> bool: |
| | """ |
| | Determine if given character should be fed in. |
| | """ |
| | raise NotImplementedError |
| |
|
| | def feed(self, character: str) -> None: |
| | """ |
| | The main routine to be executed upon character. |
| | Insert the logic in witch the text would be considered chaotic. |
| | """ |
| | raise NotImplementedError |
| |
|
| | def reset(self) -> None: |
| | """ |
| | Permit to reset the plugin to the initial state. |
| | """ |
| | raise NotImplementedError |
| |
|
| | @property |
| | def ratio(self) -> float: |
| | """ |
| | Compute the chaos ratio based on what your feed() has seen. |
| | Must NOT be lower than 0.; No restriction gt 0. |
| | """ |
| | raise NotImplementedError |
| |
|
| |
|
| | class TooManySymbolOrPunctuationPlugin(MessDetectorPlugin): |
| | def __init__(self) -> None: |
| | self._punctuation_count: int = 0 |
| | self._symbol_count: int = 0 |
| | self._character_count: int = 0 |
| |
|
| | self._last_printable_char: Optional[str] = None |
| | self._frenzy_symbol_in_word: bool = False |
| |
|
| | def eligible(self, character: str) -> bool: |
| | return character.isprintable() |
| |
|
| | def feed(self, character: str) -> None: |
| | self._character_count += 1 |
| |
|
| | if ( |
| | character != self._last_printable_char |
| | and character not in COMMON_SAFE_ASCII_CHARACTERS |
| | ): |
| | if is_punctuation(character): |
| | self._punctuation_count += 1 |
| | elif ( |
| | character.isdigit() is False |
| | and is_symbol(character) |
| | and is_emoticon(character) is False |
| | ): |
| | self._symbol_count += 2 |
| |
|
| | self._last_printable_char = character |
| |
|
| | def reset(self) -> None: |
| | self._punctuation_count = 0 |
| | self._character_count = 0 |
| | self._symbol_count = 0 |
| |
|
| | @property |
| | def ratio(self) -> float: |
| | if self._character_count == 0: |
| | return 0.0 |
| |
|
| | ratio_of_punctuation: float = ( |
| | self._punctuation_count + self._symbol_count |
| | ) / self._character_count |
| |
|
| | return ratio_of_punctuation if ratio_of_punctuation >= 0.3 else 0.0 |
| |
|
| |
|
| | class TooManyAccentuatedPlugin(MessDetectorPlugin): |
| | def __init__(self) -> None: |
| | self._character_count: int = 0 |
| | self._accentuated_count: int = 0 |
| |
|
| | def eligible(self, character: str) -> bool: |
| | return character.isalpha() |
| |
|
| | def feed(self, character: str) -> None: |
| | self._character_count += 1 |
| |
|
| | if is_accentuated(character): |
| | self._accentuated_count += 1 |
| |
|
| | def reset(self) -> None: |
| | self._character_count = 0 |
| | self._accentuated_count = 0 |
| |
|
| | @property |
| | def ratio(self) -> float: |
| | if self._character_count < 8: |
| | return 0.0 |
| |
|
| | ratio_of_accentuation: float = self._accentuated_count / self._character_count |
| | return ratio_of_accentuation if ratio_of_accentuation >= 0.35 else 0.0 |
| |
|
| |
|
| | class UnprintablePlugin(MessDetectorPlugin): |
| | def __init__(self) -> None: |
| | self._unprintable_count: int = 0 |
| | self._character_count: int = 0 |
| |
|
| | def eligible(self, character: str) -> bool: |
| | return True |
| |
|
| | def feed(self, character: str) -> None: |
| | if is_unprintable(character): |
| | self._unprintable_count += 1 |
| | self._character_count += 1 |
| |
|
| | def reset(self) -> None: |
| | self._unprintable_count = 0 |
| |
|
| | @property |
| | def ratio(self) -> float: |
| | if self._character_count == 0: |
| | return 0.0 |
| |
|
| | return (self._unprintable_count * 8) / self._character_count |
| |
|
| |
|
| | class SuspiciousDuplicateAccentPlugin(MessDetectorPlugin): |
| | def __init__(self) -> None: |
| | self._successive_count: int = 0 |
| | self._character_count: int = 0 |
| |
|
| | self._last_latin_character: Optional[str] = None |
| |
|
| | def eligible(self, character: str) -> bool: |
| | return character.isalpha() and is_latin(character) |
| |
|
| | def feed(self, character: str) -> None: |
| | self._character_count += 1 |
| | if ( |
| | self._last_latin_character is not None |
| | and is_accentuated(character) |
| | and is_accentuated(self._last_latin_character) |
| | ): |
| | if character.isupper() and self._last_latin_character.isupper(): |
| | self._successive_count += 1 |
| | |
| | if remove_accent(character) == remove_accent(self._last_latin_character): |
| | self._successive_count += 1 |
| | self._last_latin_character = character |
| |
|
| | def reset(self) -> None: |
| | self._successive_count = 0 |
| | self._character_count = 0 |
| | self._last_latin_character = None |
| |
|
| | @property |
| | def ratio(self) -> float: |
| | if self._character_count == 0: |
| | return 0.0 |
| |
|
| | return (self._successive_count * 2) / self._character_count |
| |
|
| |
|
| | class SuspiciousRange(MessDetectorPlugin): |
| | def __init__(self) -> None: |
| | self._suspicious_successive_range_count: int = 0 |
| | self._character_count: int = 0 |
| | self._last_printable_seen: Optional[str] = None |
| |
|
| | def eligible(self, character: str) -> bool: |
| | return character.isprintable() |
| |
|
| | def feed(self, character: str) -> None: |
| | self._character_count += 1 |
| |
|
| | if ( |
| | character.isspace() |
| | or is_punctuation(character) |
| | or character in COMMON_SAFE_ASCII_CHARACTERS |
| | ): |
| | self._last_printable_seen = None |
| | return |
| |
|
| | if self._last_printable_seen is None: |
| | self._last_printable_seen = character |
| | return |
| |
|
| | unicode_range_a: Optional[str] = unicode_range(self._last_printable_seen) |
| | unicode_range_b: Optional[str] = unicode_range(character) |
| |
|
| | if is_suspiciously_successive_range(unicode_range_a, unicode_range_b): |
| | self._suspicious_successive_range_count += 1 |
| |
|
| | self._last_printable_seen = character |
| |
|
| | def reset(self) -> None: |
| | self._character_count = 0 |
| | self._suspicious_successive_range_count = 0 |
| | self._last_printable_seen = None |
| |
|
| | @property |
| | def ratio(self) -> float: |
| | if self._character_count <= 13: |
| | return 0.0 |
| |
|
| | ratio_of_suspicious_range_usage: float = ( |
| | self._suspicious_successive_range_count * 2 |
| | ) / self._character_count |
| |
|
| | return ratio_of_suspicious_range_usage |
| |
|
| |
|
| | class SuperWeirdWordPlugin(MessDetectorPlugin): |
| | def __init__(self) -> None: |
| | self._word_count: int = 0 |
| | self._bad_word_count: int = 0 |
| | self._foreign_long_count: int = 0 |
| |
|
| | self._is_current_word_bad: bool = False |
| | self._foreign_long_watch: bool = False |
| |
|
| | self._character_count: int = 0 |
| | self._bad_character_count: int = 0 |
| |
|
| | self._buffer: str = "" |
| | self._buffer_accent_count: int = 0 |
| | self._buffer_glyph_count: int = 0 |
| |
|
| | def eligible(self, character: str) -> bool: |
| | return True |
| |
|
| | def feed(self, character: str) -> None: |
| | if character.isalpha(): |
| | self._buffer += character |
| | if is_accentuated(character): |
| | self._buffer_accent_count += 1 |
| | if ( |
| | self._foreign_long_watch is False |
| | and (is_latin(character) is False or is_accentuated(character)) |
| | and is_cjk(character) is False |
| | and is_hangul(character) is False |
| | and is_katakana(character) is False |
| | and is_hiragana(character) is False |
| | and is_thai(character) is False |
| | ): |
| | self._foreign_long_watch = True |
| | if ( |
| | is_cjk(character) |
| | or is_hangul(character) |
| | or is_katakana(character) |
| | or is_hiragana(character) |
| | or is_thai(character) |
| | ): |
| | self._buffer_glyph_count += 1 |
| | return |
| | if not self._buffer: |
| | return |
| | if ( |
| | character.isspace() or is_punctuation(character) or is_separator(character) |
| | ) and self._buffer: |
| | self._word_count += 1 |
| | buffer_length: int = len(self._buffer) |
| |
|
| | self._character_count += buffer_length |
| |
|
| | if buffer_length >= 4: |
| | if self._buffer_accent_count / buffer_length >= 0.5: |
| | self._is_current_word_bad = True |
| | |
| | |
| | elif ( |
| | is_accentuated(self._buffer[-1]) |
| | and self._buffer[-1].isupper() |
| | and all(_.isupper() for _ in self._buffer) is False |
| | ): |
| | self._foreign_long_count += 1 |
| | self._is_current_word_bad = True |
| | elif self._buffer_glyph_count == 1: |
| | self._is_current_word_bad = True |
| | self._foreign_long_count += 1 |
| | if buffer_length >= 24 and self._foreign_long_watch: |
| | camel_case_dst = [ |
| | i |
| | for c, i in zip(self._buffer, range(0, buffer_length)) |
| | if c.isupper() |
| | ] |
| | probable_camel_cased: bool = False |
| |
|
| | if camel_case_dst and (len(camel_case_dst) / buffer_length <= 0.3): |
| | probable_camel_cased = True |
| |
|
| | if not probable_camel_cased: |
| | self._foreign_long_count += 1 |
| | self._is_current_word_bad = True |
| |
|
| | if self._is_current_word_bad: |
| | self._bad_word_count += 1 |
| | self._bad_character_count += len(self._buffer) |
| | self._is_current_word_bad = False |
| |
|
| | self._foreign_long_watch = False |
| | self._buffer = "" |
| | self._buffer_accent_count = 0 |
| | self._buffer_glyph_count = 0 |
| | elif ( |
| | character not in {"<", ">", "-", "=", "~", "|", "_"} |
| | and character.isdigit() is False |
| | and is_symbol(character) |
| | ): |
| | self._is_current_word_bad = True |
| | self._buffer += character |
| |
|
| | def reset(self) -> None: |
| | self._buffer = "" |
| | self._is_current_word_bad = False |
| | self._foreign_long_watch = False |
| | self._bad_word_count = 0 |
| | self._word_count = 0 |
| | self._character_count = 0 |
| | self._bad_character_count = 0 |
| | self._foreign_long_count = 0 |
| |
|
| | @property |
| | def ratio(self) -> float: |
| | if self._word_count <= 10 and self._foreign_long_count == 0: |
| | return 0.0 |
| |
|
| | return self._bad_character_count / self._character_count |
| |
|
| |
|
| | class CjkInvalidStopPlugin(MessDetectorPlugin): |
| | """ |
| | GB(Chinese) based encoding often render the stop incorrectly when the content does not fit and |
| | can be easily detected. Searching for the overuse of '丅' and '丄'. |
| | """ |
| |
|
| | def __init__(self) -> None: |
| | self._wrong_stop_count: int = 0 |
| | self._cjk_character_count: int = 0 |
| |
|
| | def eligible(self, character: str) -> bool: |
| | return True |
| |
|
| | def feed(self, character: str) -> None: |
| | if character in {"丅", "丄"}: |
| | self._wrong_stop_count += 1 |
| | return |
| | if is_cjk(character): |
| | self._cjk_character_count += 1 |
| |
|
| | def reset(self) -> None: |
| | self._wrong_stop_count = 0 |
| | self._cjk_character_count = 0 |
| |
|
| | @property |
| | def ratio(self) -> float: |
| | if self._cjk_character_count < 16: |
| | return 0.0 |
| | return self._wrong_stop_count / self._cjk_character_count |
| |
|
| |
|
| | class ArchaicUpperLowerPlugin(MessDetectorPlugin): |
| | def __init__(self) -> None: |
| | self._buf: bool = False |
| |
|
| | self._character_count_since_last_sep: int = 0 |
| |
|
| | self._successive_upper_lower_count: int = 0 |
| | self._successive_upper_lower_count_final: int = 0 |
| |
|
| | self._character_count: int = 0 |
| |
|
| | self._last_alpha_seen: Optional[str] = None |
| | self._current_ascii_only: bool = True |
| |
|
| | def eligible(self, character: str) -> bool: |
| | return True |
| |
|
| | def feed(self, character: str) -> None: |
| | is_concerned = character.isalpha() and is_case_variable(character) |
| | chunk_sep = is_concerned is False |
| |
|
| | if chunk_sep and self._character_count_since_last_sep > 0: |
| | if ( |
| | self._character_count_since_last_sep <= 64 |
| | and character.isdigit() is False |
| | and self._current_ascii_only is False |
| | ): |
| | self._successive_upper_lower_count_final += ( |
| | self._successive_upper_lower_count |
| | ) |
| |
|
| | self._successive_upper_lower_count = 0 |
| | self._character_count_since_last_sep = 0 |
| | self._last_alpha_seen = None |
| | self._buf = False |
| | self._character_count += 1 |
| | self._current_ascii_only = True |
| |
|
| | return |
| |
|
| | if self._current_ascii_only is True and character.isascii() is False: |
| | self._current_ascii_only = False |
| |
|
| | if self._last_alpha_seen is not None: |
| | if (character.isupper() and self._last_alpha_seen.islower()) or ( |
| | character.islower() and self._last_alpha_seen.isupper() |
| | ): |
| | if self._buf is True: |
| | self._successive_upper_lower_count += 2 |
| | self._buf = False |
| | else: |
| | self._buf = True |
| | else: |
| | self._buf = False |
| |
|
| | self._character_count += 1 |
| | self._character_count_since_last_sep += 1 |
| | self._last_alpha_seen = character |
| |
|
| | def reset(self) -> None: |
| | self._character_count = 0 |
| | self._character_count_since_last_sep = 0 |
| | self._successive_upper_lower_count = 0 |
| | self._successive_upper_lower_count_final = 0 |
| | self._last_alpha_seen = None |
| | self._buf = False |
| | self._current_ascii_only = True |
| |
|
| | @property |
| | def ratio(self) -> float: |
| | if self._character_count == 0: |
| | return 0.0 |
| |
|
| | return self._successive_upper_lower_count_final / self._character_count |
| |
|
| |
|
| | class ArabicIsolatedFormPlugin(MessDetectorPlugin): |
| | def __init__(self) -> None: |
| | self._character_count: int = 0 |
| | self._isolated_form_count: int = 0 |
| |
|
| | def reset(self) -> None: |
| | self._character_count = 0 |
| | self._isolated_form_count = 0 |
| |
|
| | def eligible(self, character: str) -> bool: |
| | return is_arabic(character) |
| |
|
| | def feed(self, character: str) -> None: |
| | self._character_count += 1 |
| |
|
| | if is_arabic_isolated_form(character): |
| | self._isolated_form_count += 1 |
| |
|
| | @property |
| | def ratio(self) -> float: |
| | if self._character_count < 8: |
| | return 0.0 |
| |
|
| | isolated_form_usage: float = self._isolated_form_count / self._character_count |
| |
|
| | return isolated_form_usage |
| |
|
| |
|
| | @lru_cache(maxsize=1024) |
| | def is_suspiciously_successive_range( |
| | unicode_range_a: Optional[str], unicode_range_b: Optional[str] |
| | ) -> bool: |
| | """ |
| | Determine if two Unicode range seen next to each other can be considered as suspicious. |
| | """ |
| | if unicode_range_a is None or unicode_range_b is None: |
| | return True |
| |
|
| | if unicode_range_a == unicode_range_b: |
| | return False |
| |
|
| | if "Latin" in unicode_range_a and "Latin" in unicode_range_b: |
| | return False |
| |
|
| | if "Emoticons" in unicode_range_a or "Emoticons" in unicode_range_b: |
| | return False |
| |
|
| | |
| | |
| | if ("Latin" in unicode_range_a or "Latin" in unicode_range_b) and ( |
| | "Combining" in unicode_range_a or "Combining" in unicode_range_b |
| | ): |
| | return False |
| |
|
| | keywords_range_a, keywords_range_b = unicode_range_a.split( |
| | " " |
| | ), unicode_range_b.split(" ") |
| |
|
| | for el in keywords_range_a: |
| | if el in UNICODE_SECONDARY_RANGE_KEYWORD: |
| | continue |
| | if el in keywords_range_b: |
| | return False |
| |
|
| | |
| | range_a_jp_chars, range_b_jp_chars = ( |
| | unicode_range_a |
| | in ( |
| | "Hiragana", |
| | "Katakana", |
| | ), |
| | unicode_range_b in ("Hiragana", "Katakana"), |
| | ) |
| | if (range_a_jp_chars or range_b_jp_chars) and ( |
| | "CJK" in unicode_range_a or "CJK" in unicode_range_b |
| | ): |
| | return False |
| | if range_a_jp_chars and range_b_jp_chars: |
| | return False |
| |
|
| | if "Hangul" in unicode_range_a or "Hangul" in unicode_range_b: |
| | if "CJK" in unicode_range_a or "CJK" in unicode_range_b: |
| | return False |
| | if unicode_range_a == "Basic Latin" or unicode_range_b == "Basic Latin": |
| | return False |
| |
|
| | |
| | if ("CJK" in unicode_range_a or "CJK" in unicode_range_b) or ( |
| | unicode_range_a in ["Katakana", "Hiragana"] |
| | and unicode_range_b in ["Katakana", "Hiragana"] |
| | ): |
| | if "Punctuation" in unicode_range_a or "Punctuation" in unicode_range_b: |
| | return False |
| | if "Forms" in unicode_range_a or "Forms" in unicode_range_b: |
| | return False |
| | if unicode_range_a == "Basic Latin" or unicode_range_b == "Basic Latin": |
| | return False |
| |
|
| | return True |
| |
|
| |
|
| | @lru_cache(maxsize=2048) |
| | def mess_ratio( |
| | decoded_sequence: str, maximum_threshold: float = 0.2, debug: bool = False |
| | ) -> float: |
| | """ |
| | Compute a mess ratio given a decoded bytes sequence. The maximum threshold does stop the computation earlier. |
| | """ |
| |
|
| | detectors: List[MessDetectorPlugin] = [ |
| | md_class() for md_class in MessDetectorPlugin.__subclasses__() |
| | ] |
| |
|
| | length: int = len(decoded_sequence) + 1 |
| |
|
| | mean_mess_ratio: float = 0.0 |
| |
|
| | if length < 512: |
| | intermediary_mean_mess_ratio_calc: int = 32 |
| | elif length <= 1024: |
| | intermediary_mean_mess_ratio_calc = 64 |
| | else: |
| | intermediary_mean_mess_ratio_calc = 128 |
| |
|
| | for character, index in zip(decoded_sequence + "\n", range(length)): |
| | for detector in detectors: |
| | if detector.eligible(character): |
| | detector.feed(character) |
| |
|
| | if ( |
| | index > 0 and index % intermediary_mean_mess_ratio_calc == 0 |
| | ) or index == length - 1: |
| | mean_mess_ratio = sum(dt.ratio for dt in detectors) |
| |
|
| | if mean_mess_ratio >= maximum_threshold: |
| | break |
| |
|
| | if debug: |
| | logger = getLogger("charset_normalizer") |
| |
|
| | logger.log( |
| | TRACE, |
| | "Mess-detector extended-analysis start. " |
| | f"intermediary_mean_mess_ratio_calc={intermediary_mean_mess_ratio_calc} mean_mess_ratio={mean_mess_ratio} " |
| | f"maximum_threshold={maximum_threshold}", |
| | ) |
| |
|
| | if len(decoded_sequence) > 16: |
| | logger.log(TRACE, f"Starting with: {decoded_sequence[:16]}") |
| | logger.log(TRACE, f"Ending with: {decoded_sequence[-16::]}") |
| |
|
| | for dt in detectors: |
| | logger.log(TRACE, f"{dt.__class__}: {dt.ratio}") |
| |
|
| | return round(mean_mess_ratio, 3) |
| |
|