Skip to content
Snippets Groups Projects
SimTexter.py 9.73 KiB
Newer Older
  • Learn to ignore specific revisions
  • Frederik Arnold's avatar
    Frederik Arnold committed
    from sim.Match import Match
    from sim.MatchSegment import MatchSegment
    from sim.Text import Text
    import re
    from sim.Token import Token
    from rapidfuzz import fuzz, process
    from datasketch import MinHash, MinHashLSH
    
    class SimTexter:
    
        def __init__(self, min_match_length):
            self.min_match_length = min_match_length
            self.cache = {}
    
        def compare(self, input_texts):
    
            (texts, tokens) = self.read_input(input_texts)
    
            mts_tags = {}
            forward_references = {}
            existing_tags = []
            lsh = MinHashLSH(threshold=0.80, num_perm=128)
    
            for i in range(0, len(texts)):
                (mts_tags, forward_references, existing_tags, lsh) = self.make_forward_references(i, texts[i], tokens, mts_tags, existing_tags, forward_references, lsh)
    
            similarities = self.get_similarities(tokens, texts, 0, 1, forward_references)
    
            return similarities
    
            # self.print_similarities(similarities, input_texts)
    
        def read_input(self, input_texts):
    
            texts = []
            tokens = []
    
            for input_text in input_texts:
                nr_of_characters = len(input_text)
                nr_of_words = len(input_text.split())
                file_name = 'dummy'
                tk_start_pos = len(tokens)
    
                tokens.extend(self.tokenize_text(input_text))
                tk_end_pos = len(tokens)
                text = Text('Text', nr_of_characters, nr_of_words, file_name, tk_start_pos, tk_end_pos)
                texts.append(text)
    
            return texts, tokens
    
        def tokenize_text(self, input_text):
            cleaned_text = self.clean_text(input_text)
    
            tokens = []
    
            for match in re.finditer("[^\\s]+", cleaned_text):
                token = self.clean_word(match.group())
    
                if len(token) > 0:
                    text_begin_pos = match.start()
                    text_end_pos = match.end()
    
                    tokens.append(Token(token, text_begin_pos, text_end_pos))
    
            return tokens
    
        def clean_text(self, input_text):
            # TODO: optional machen
    
            input_text = re.sub("[.?!,;:/()'+\\-\\[\\]‚‘…]", " ", input_text)
            input_text = re.sub("[0-9]", " ", input_text)
    
            return input_text.lower()
    
        def clean_word(self, input_word):
            # TODO: Umlaute ersetzen, optional machen
            return input_word
    
        def make_forward_references(self, text_index, text, tokens, mts_tags, existing_tags, forward_references, lsh):
            text_begin_pos = text.tk_start_pos
            text_end_pos = text.tk_end_pos
    
            for i in range(text_begin_pos, text_end_pos - self.min_match_length):
                tag = ''
    
                for token in tokens[i: i + self.min_match_length]:
                    tag = tag + token.text
    
                # TODO: geht das fuzzy??
    
                # if tag in mts_tags:
                #    forward_references[mts_tags[tag]] = i
    
                # mts_tags[tag] = i
    
                # if text_index == 0:
                #     existing_tags.append(tag)
                # else:
                #     best_existing_tag = process.extractOne(tag, existing_tags, scorer=fuzz.ratio, score_cutoff=80)
                #
                #     if best_existing_tag:
                #         forward_references[mts_tags[best_existing_tag[0]]] = i
    
                if text_index == 0:
                    my_set = set(tag)
                    min_hash = MinHash(num_perm=128)
    
                    for d in my_set:
                        min_hash.update(d.encode('utf8'))
    
                    lsh.insert(tag, min_hash, False)
                else:
                    my_set = set(tag)
                    min_hash = MinHash(num_perm=128)
    
                    for d in my_set:
                        min_hash.update(d.encode('utf8'))
    
                    result = lsh.query(min_hash)
    
                    if result and len(result) > 0:
                        closest_match = self.get_closest_match(result, tag)
                        if closest_match:
                            forward_references[mts_tags[closest_match]] = i
    
                mts_tags[tag] = i
    
            return mts_tags, forward_references, existing_tags, lsh
    
        def get_similarities(self, tokens, texts, source_text_index, target_text_index, forward_references):
            source_token_start_pos = texts[source_text_index].tk_start_pos
            source_token_end_pos = texts[source_text_index].tk_end_pos
    
            similarities = []
    
            while source_token_start_pos + self.min_match_length <= source_token_end_pos:
                best_match = self.get_best_match(tokens, texts, source_text_index, target_text_index, source_token_start_pos,
                                            forward_references)
    
                if best_match and best_match.length > 0:
                    source_character_start_pos = tokens[best_match.source_token_start_pos].start_pos
                    source_character_end_pos = tokens[best_match.source_token_start_pos + best_match.length - 1].end_pos
                    target_character_start_pos = tokens[best_match.target_token_start_pos].start_pos
                    target_character_end_pos = tokens[best_match.target_token_start_pos + best_match.length - 1].end_pos
    
                    similarities.append((MatchSegment(best_match.source_text_index, best_match.source_token_start_pos,
                                                      best_match.length, source_character_start_pos, source_character_end_pos),
                                         MatchSegment(best_match.target_text_index, best_match.target_token_start_pos,
                                                      best_match.length, target_character_start_pos, target_character_end_pos)))
    
                    source_token_start_pos = source_token_start_pos + best_match.length
                else:
                    source_token_start_pos = source_token_start_pos + 1
    
            return similarities
    
        def get_best_match(self, tokens, texts, source_text_index, target_text_index, source_token_start_pos, forward_references):
            best_match_length = 0
            token_pos = source_token_start_pos
    
            source_token_pos = 0
            target_token_pos = 0
    
            best_match_token_pos = 0
    
            best_match = None
    
            while 0 < token_pos < len(tokens):
    
                if token_pos < texts[target_text_index].tk_start_pos:
                    if token_pos in forward_references:
                        token_pos = forward_references[token_pos]
                    else:
                        token_pos = -1
                    continue
    
                min_match_length = self.min_match_length
    
                if best_match_length > 0:
                    min_match_length = best_match_length + 1
    
                source_token_pos = source_token_start_pos + min_match_length - 1
                target_token_pos = token_pos + min_match_length - 1
    
                if source_token_pos < texts[source_text_index].tk_end_pos and texts[
                    target_text_index].tk_end_pos > target_token_pos >= source_token_pos + min_match_length:
    
                    cnt = min_match_length
    
                    while cnt > 0 and self.fuzzy_match(tokens[source_token_pos].text, tokens[target_token_pos].text) > 80:
                        source_token_pos = source_token_pos - 1
                        target_token_pos = target_token_pos - 1
                        cnt = cnt - 1
    
                    if cnt > 0:
                        if token_pos in forward_references:
                            token_pos = forward_references[token_pos]
                        else:
                            token_pos = -1
                        continue
                else:
                    if token_pos in forward_references:
                        token_pos = forward_references[token_pos]
                    else:
                        token_pos = -1
                    continue
    
                new_match_length = min_match_length
                source_token_pos = source_token_start_pos + min_match_length
                target_token_pos = token_pos + min_match_length
    
                while source_token_pos < texts[source_text_index].tk_end_pos and texts[
                    target_text_index].tk_end_pos > target_token_pos > source_token_pos + \
                        new_match_length and self.fuzzy_match(tokens[source_token_pos].text,
                                                              tokens[target_token_pos].text) > 80:
    
                    source_token_pos = source_token_pos + 1
                    target_token_pos = target_token_pos + 1
                    new_match_length = new_match_length + 1
    
                if new_match_length >= self.min_match_length and new_match_length > best_match_length:
                    best_match_length = new_match_length
                    best_match_token_pos = token_pos
                    best_match = Match(source_text_index, source_token_start_pos, target_text_index, best_match_token_pos,
                                       best_match_length)
    
                if token_pos in forward_references:
                    token_pos = forward_references[token_pos]
                else:
                    token_pos = -1
    
            return best_match
    
        def fuzzy_match(self, input1, input2):
    
            # if input1 + input2 in self.cache:
            #    return self.cache[input1 + input2]
    
            # if abs(len(input1) - len(input2)) >= 3:
            #    self.cache[input1 + input2] = 0
            #    return 0
    
            ratio = fuzz.ratio(input1, input2)
            # self.cache[input1 + input2] = ratio
            return ratio
    
        def get_closest_match(self, candidates, word):
            if word in candidates:
                return word
    
            best_existing_tag = process.extractOne(word, candidates, scorer=fuzz.ratio, score_cutoff=80)
    
            if best_existing_tag:
                return best_existing_tag[0]
    
            return None
    
        def print_similarities(self, similarities, input_texts):
            for similarity_tuple in similarities:
                similarity_literature = similarity_tuple[0]
                similarity_scientific = similarity_tuple[1]
    
                print('{0}, {1}'.format(similarity_literature, similarity_scientific))
                print(input_texts[0][similarity_literature.character_start_pos:similarity_literature.character_end_pos])