# -*- coding: utf-8 -*- # This work is licensed under the MIT License. # To view a copy of this license, visit https://opensource.org/licenses/MIT # Written by Abdullah Diab (mpcabd) # Email: mpcabd@gmail.com # Website: http://mpcabd.xyz import re from functools import cached_property from itertools import repeat from .ligatures import LIGATURES from .reshaper_config import auto_config from .letters import (UNSHAPED, ISOLATED, TATWEEL, ZWJ, LETTERS_ARABIC, LETTERS_ARABIC_V2, LETTERS_KURDISH, FINAL, INITIAL, MEDIAL, connects_with_letters_before_and_after, connects_with_letter_before, connects_with_letter_after) HARAKAT_RE = re.compile( '[' '\u0610-\u061a' '\u064b-\u065f' '\u0670' '\u06d6-\u06dc' '\u06df-\u06e8' '\u06ea-\u06ed' '\u08d4-\u08e1' '\u08d4-\u08ed' '\u08e3-\u08ff' ']', re.UNICODE | re.X ) class ArabicReshaper: """ A class for Arabic reshaper, it allows for fine-tune configuration over the API. If no configuration is passed to the constructor, the class will check for an environment variable :envvar:`PYTHON_ARABIC_RESHAPER_CONFIGURATION_FILE` , if the variable is available, the class will load the file pointed to by the variable, and will read it as an ini file. If the variable doesn't exist, the class will load with the default configuration file :file:`default-config.ini` Check these links for information on the configuration files format: * Python 3: https://docs.python.org/3/library/configparser.html See the default configuration file :file:`default-config.ini` for details on how to configure your reshaper. """ def __init__(self, configuration=None, configuration_file=None): super().__init__() self.configuration = auto_config(configuration, configuration_file) self.language = self.configuration.get('language') if self.language == 'ArabicV2': self.letters = LETTERS_ARABIC_V2 elif self.language == 'Kurdish': self.letters = LETTERS_KURDISH else: self.letters = LETTERS_ARABIC @cached_property def _ligatures_re(self): patterns = [] self._re_group_index_to_ligature_forms = {} index = 0 FORMS = 1 MATCH = 0 for ligature, replacement in LIGATURES: if not self.configuration.getboolean(ligature): continue self._re_group_index_to_ligature_forms[index] = replacement[FORMS] patterns.append(f'({replacement[MATCH]})') index += 1 return re.compile('|'.join(patterns), re.UNICODE) def _get_ligature_forms_from_re_group_index(self, group_index): return self._re_group_index_to_ligature_forms[group_index] def reshape(self, text: str) -> str: if not text: return '' output = [] LETTER = 0 FORM = 1 NOT_SUPPORTED = -1 delete_harakat = self.configuration.getboolean('delete_harakat') delete_tatweel = self.configuration.getboolean('delete_tatweel') support_zwj = self.configuration.getboolean('support_zwj') shift_harakat_position = self.configuration.getboolean( 'shift_harakat_position' ) use_unshaped_instead_of_isolated = self.configuration.getboolean( 'use_unshaped_instead_of_isolated' ) positions_harakat = {} isolated_form = (UNSHAPED if use_unshaped_instead_of_isolated else ISOLATED) for letter in text: if HARAKAT_RE.match(letter): if not delete_harakat: position = len(output) - 1 if shift_harakat_position: position -= 1 if position not in positions_harakat: positions_harakat[position] = [] if shift_harakat_position: positions_harakat[position].insert(0, letter) else: positions_harakat[position].append(letter) elif letter == TATWEEL and delete_tatweel: pass elif letter == ZWJ and not support_zwj: pass elif letter not in self.letters: output.append((letter, NOT_SUPPORTED)) elif not output: # first letter output.append((letter, isolated_form)) else: previous_letter = output[-1] if previous_letter[FORM] == NOT_SUPPORTED: output.append((letter, isolated_form)) elif not connects_with_letter_before(letter, self.letters): output.append((letter, isolated_form)) elif not connects_with_letter_after( previous_letter[LETTER], self.letters): output.append((letter, isolated_form)) elif (previous_letter[FORM] == FINAL and not connects_with_letters_before_and_after( previous_letter[LETTER], self.letters )): output.append((letter, isolated_form)) elif previous_letter[FORM] == isolated_form: output[-1] = ( previous_letter[LETTER], INITIAL ) output.append((letter, FINAL)) # Otherwise, we will change the previous letter to connect # to the current letter else: output[-1] = ( previous_letter[LETTER], MEDIAL ) output.append((letter, FINAL)) # Remove ZWJ if it's the second to last item as it won't be useful if support_zwj and len(output) > 1 and output[-2][LETTER] == ZWJ: output.pop(len(output) - 2) if support_zwj and output and output[-1][LETTER] == ZWJ: output.pop() if self.configuration.getboolean('support_ligatures'): # Clean text from Harakat to be able to find ligatures text = HARAKAT_RE.sub('', text) # Clean text from Tatweel to find ligatures if delete_tatweel if delete_tatweel: text = text.replace(TATWEEL, '') for match in re.finditer(self._ligatures_re, text): group_index = next(( i for i, group in enumerate(match.groups()) if group ), -1) forms = self._get_ligature_forms_from_re_group_index( group_index ) a, b = match.span() a_form = output[a][FORM] b_form = output[b - 1][FORM] ligature_form = None # +-----------+----------+---------+---------+----------+ # | a \ b | ISOLATED | INITIAL | MEDIAL | FINAL | # +-----------+----------+---------+---------+----------+ # | ISOLATED | ISOLATED | INITIAL | INITIAL | ISOLATED | # | INITIAL | ISOLATED | INITIAL | INITIAL | ISOLATED | # | MEDIAL | FINAL | MEDIAL | MEDIAL | FINAL | # | FINAL | FINAL | MEDIAL | MEDIAL | FINAL | # +-----------+----------+---------+---------+----------+ if a_form in (isolated_form, INITIAL): if b_form in (isolated_form, FINAL): ligature_form = ISOLATED else: ligature_form = INITIAL else: if b_form in (isolated_form, FINAL): ligature_form = FINAL else: ligature_form = MEDIAL if not forms[ligature_form]: continue output[a] = (forms[ligature_form], NOT_SUPPORTED) # Pad the replaced positions with empty sentinels so that # Harakat position indices remain aligned with the output list. output[a+1:b] = repeat(('', NOT_SUPPORTED), b - 1 - a) result = [] if not delete_harakat and -1 in positions_harakat: result.extend(positions_harakat[-1]) for i, o in enumerate(output): if o[LETTER]: if o[FORM] == NOT_SUPPORTED or o[FORM] == UNSHAPED: result.append(o[LETTER]) else: result.append(self.letters[o[LETTER]][o[FORM]]) if not delete_harakat: if i in positions_harakat: result.extend(positions_harakat[i]) return ''.join(result) default_reshaper = ArabicReshaper() reshape = default_reshaper.reshape