import importlib import logging import unicodedata from codecs import IncrementalDecoder from encodings.aliases import aliases from functools import lru_cache from re import findall from typing import Generator, List, Optional, Set, Tuple, Union from _multibytecodec import MultibyteIncrementalDecoder from .constant import ( ENCODING_MARKS, IANA_SUPPORTED_SIMILAR, RE_POSSIBLE_ENCODING_INDICATION, UNICODE_RANGES_COMBINED, UNICODE_SECONDARY_RANGE_KEYWORD, UTF8_MAXIMAL_ALLOCATION, ) @lru_cache(maxsize=UTF8_MAXIMAL_ALLOCATION) def is_accentuated(character: str) -> bool: try: description: str = unicodedata.name(character) except ValueError: return False return ( "WITH GRAVE" in description or "WITH ACUTE" in description or "WITH CEDILLA" in description or "WITH DIAERESIS" in description or "WITH CIRCUMFLEX" in description or "WITH TILDE" in description or "WITH MACRON" in description or "WITH RING ABOVE" in description ) @lru_cache(maxsize=UTF8_MAXIMAL_ALLOCATION) def remove_accent(character: str) -> str: decomposed: str = unicodedata.decomposition(character) if not decomposed: return character codes: List[str] = decomposed.split(" ") return chr(int(codes[0], 16)) @lru_cache(maxsize=UTF8_MAXIMAL_ALLOCATION) def unicode_range(character: str) -> Optional[str]: """ Retrieve the Unicode range official name from a single character. """ character_ord: int = ord(character) for range_name, ord_range in UNICODE_RANGES_COMBINED.items(): if character_ord in ord_range: return range_name return None @lru_cache(maxsize=UTF8_MAXIMAL_ALLOCATION) def is_latin(character: str) -> bool: try: description: str = unicodedata.name(character) except ValueError: return False return "LATIN" in description @lru_cache(maxsize=UTF8_MAXIMAL_ALLOCATION) def is_punctuation(character: str) -> bool: character_category: str = unicodedata.category(character) if "P" in character_category: return True character_range: Optional[str] = unicode_range(character) if character_range is None: return False return "Punctuation" in character_range @lru_cache(maxsize=UTF8_MAXIMAL_ALLOCATION) def is_symbol(character: str) -> bool: character_category: str = unicodedata.category(character) if "S" in character_category or "N" in character_category: return True character_range: Optional[str] = unicode_range(character) if character_range is None: return False return "Forms" in character_range and character_category != "Lo" @lru_cache(maxsize=UTF8_MAXIMAL_ALLOCATION) def is_emoticon(character: str) -> bool: character_range: Optional[str] = unicode_range(character) if character_range is None: return False return "Emoticons" in character_range or "Pictographs" in character_range @lru_cache(maxsize=UTF8_MAXIMAL_ALLOCATION) def is_separator(character: str) -> bool: if character.isspace() or character in {"|", "+", "<", ">"}: return True character_category: str = unicodedata.category(character) return "Z" in character_category or character_category in {"Po", "Pd", "Pc"} @lru_cache(maxsize=UTF8_MAXIMAL_ALLOCATION) def is_case_variable(character: str) -> bool: return character.islower() != character.isupper() @lru_cache(maxsize=UTF8_MAXIMAL_ALLOCATION) def is_cjk(character: str) -> bool: try: character_name = unicodedata.name(character) except ValueError: return False return "CJK" in character_name @lru_cache(maxsize=UTF8_MAXIMAL_ALLOCATION) def is_hiragana(character: str) -> bool: try: character_name = unicodedata.name(character) except ValueError: return False return "HIRAGANA" in character_name @lru_cache(maxsize=UTF8_MAXIMAL_ALLOCATION) def is_katakana(character: str) -> bool: try: character_name = unicodedata.name(character) except ValueError: return False return "KATAKANA" in character_name @lru_cache(maxsize=UTF8_MAXIMAL_ALLOCATION) def is_hangul(character: str) -> bool: try: character_name = unicodedata.name(character) except ValueError: return False return "HANGUL" in character_name @lru_cache(maxsize=UTF8_MAXIMAL_ALLOCATION) def is_thai(character: str) -> bool: try: character_name = unicodedata.name(character) except ValueError: return False return "THAI" in character_name @lru_cache(maxsize=UTF8_MAXIMAL_ALLOCATION) def is_arabic(character: str) -> bool: try: character_name = unicodedata.name(character) except ValueError: return False return "ARABIC" in character_name @lru_cache(maxsize=UTF8_MAXIMAL_ALLOCATION) def is_arabic_isolated_form(character: str) -> bool: try: character_name = unicodedata.name(character) except ValueError: return False return "ARABIC" in character_name and "ISOLATED FORM" in character_name @lru_cache(maxsize=len(UNICODE_RANGES_COMBINED)) def is_unicode_range_secondary(range_name: str) -> bool: return any(keyword in range_name for keyword in UNICODE_SECONDARY_RANGE_KEYWORD) @lru_cache(maxsize=UTF8_MAXIMAL_ALLOCATION) def is_unprintable(character: str) -> bool: return ( character.isspace() is False # includes \n \t \r \v and character.isprintable() is False and character != "\x1A" # Why? Its the ASCII substitute character. and character != "\ufeff" # bug discovered in Python, # Zero Width No-Break Space located in Arabic Presentation Forms-B, Unicode 1.1 not acknowledged as space. ) def any_specified_encoding(sequence: bytes, search_zone: int = 8192) -> Optional[str]: """ Extract using ASCII-only decoder any specified encoding in the first n-bytes. """ if not isinstance(sequence, bytes): raise TypeError seq_len: int = len(sequence) results: List[str] = findall( RE_POSSIBLE_ENCODING_INDICATION, sequence[: min(seq_len, search_zone)].decode("ascii", errors="ignore"), ) if len(results) == 0: return None for specified_encoding in results: specified_encoding = specified_encoding.lower().replace("-", "_") encoding_alias: str encoding_iana: str for encoding_alias, encoding_iana in aliases.items(): if encoding_alias == specified_encoding: return encoding_iana if encoding_iana == specified_encoding: return encoding_iana return None @lru_cache(maxsize=128) def is_multi_byte_encoding(name: str) -> bool: """ Verify is a specific encoding is a multi byte one based on it IANA name """ return name in { "utf_8", "utf_8_sig", "utf_16", "utf_16_be", "utf_16_le", "utf_32", "utf_32_le", "utf_32_be", "utf_7", } or issubclass( importlib.import_module("encodings.{}".format(name)).IncrementalDecoder, MultibyteIncrementalDecoder, ) def identify_sig_or_bom(sequence: bytes) -> Tuple[Optional[str], bytes]: """ Identify and extract SIG/BOM in given sequence. """ for iana_encoding in ENCODING_MARKS: marks: Union[bytes, List[bytes]] = ENCODING_MARKS[iana_encoding] if isinstance(marks, bytes): marks = [marks] for mark in marks: if sequence.startswith(mark): return iana_encoding, mark return None, b"" def should_strip_sig_or_bom(iana_encoding: str) -> bool: return iana_encoding not in {"utf_16", "utf_32"} def iana_name(cp_name: str, strict: bool = True) -> str: cp_name = cp_name.lower().replace("-", "_") encoding_alias: str encoding_iana: str for encoding_alias, encoding_iana in aliases.items(): if cp_name in [encoding_alias, encoding_iana]: return encoding_iana if strict: raise ValueError("Unable to retrieve IANA for '{}'".format(cp_name)) return cp_name def range_scan(decoded_sequence: str) -> List[str]: ranges: Set[str] = set() for character in decoded_sequence: character_range: Optional[str] = unicode_range(character) if character_range is None: continue ranges.add(character_range) return list(ranges) def cp_similarity(iana_name_a: str, iana_name_b: str) -> float: if is_multi_byte_encoding(iana_name_a) or is_multi_byte_encoding(iana_name_b): return 0.0 decoder_a = importlib.import_module( "encodings.{}".format(iana_name_a) ).IncrementalDecoder decoder_b = importlib.import_module( "encodings.{}".format(iana_name_b) ).IncrementalDecoder id_a: IncrementalDecoder = decoder_a(errors="ignore") id_b: IncrementalDecoder = decoder_b(errors="ignore") character_match_count: int = 0 for i in range(255): to_be_decoded: bytes = bytes([i]) if id_a.decode(to_be_decoded) == id_b.decode(to_be_decoded): character_match_count += 1 return character_match_count / 254 def is_cp_similar(iana_name_a: str, iana_name_b: str) -> bool: """ Determine if two code page are at least 80% similar. IANA_SUPPORTED_SIMILAR dict was generated using the function cp_similarity. """ return ( iana_name_a in IANA_SUPPORTED_SIMILAR and iana_name_b in IANA_SUPPORTED_SIMILAR[iana_name_a] ) def set_logging_handler( name: str = "charset_normalizer", level: int = logging.INFO, format_string: str = "%(asctime)s | %(levelname)s | %(message)s", ) -> None: logger = logging.getLogger(name) logger.setLevel(level) handler = logging.StreamHandler() handler.setFormatter(logging.Formatter(format_string)) logger.addHandler(handler) def cut_sequence_chunks( sequences: bytes, encoding_iana: str, offsets: range, chunk_size: int, bom_or_sig_available: bool, strip_sig_or_bom: bool, sig_payload: bytes, is_multi_byte_decoder: bool, decoded_payload: Optional[str] = None, ) -> Generator[str, None, None]: if decoded_payload and is_multi_byte_decoder is False: for i in offsets: chunk = decoded_payload[i : i + chunk_size] if not chunk: break yield chunk else: for i in offsets: chunk_end = i + chunk_size if chunk_end > len(sequences) + 8: continue cut_sequence = sequences[i : i + chunk_size] if bom_or_sig_available and strip_sig_or_bom is False: cut_sequence = sig_payload + cut_sequence chunk = cut_sequence.decode( encoding_iana, errors="ignore" if is_multi_byte_decoder else "strict", ) # multi-byte bad cutting detector and adjustment # not the cleanest way to perform that fix but clever enough for now. if is_multi_byte_decoder and i > 0: chunk_partial_size_chk: int = min(chunk_size, 16) if ( decoded_payload and chunk[:chunk_partial_size_chk] not in decoded_payload ): for j in range(i, i - 4, -1): cut_sequence = sequences[j:chunk_end] if bom_or_sig_available and strip_sig_or_bom is False: cut_sequence = sig_payload + cut_sequence chunk = cut_sequence.decode(encoding_iana, errors="ignore") if chunk[:chunk_partial_size_chk] in decoded_payload: break yield chunk