def initialize_detector(self):
t1 = time.time()
try:
import kenlm
except ImportError:
raise ImportError(
'pycorrector dependencies are not fully installed, '
'they are required for statistical language model.'
'Please use "pip install kenlm" to install it.'
'if you are Win, Please install kenlm in cgwin.')
if not os.path.exists(self.language_model_path):
filename = self.pre_trained_language_models.get(
self.language_model_path, 'zh_giga.no_cna_cmn.prune01244.klm')
url = self.pre_trained_language_models.get(filename)
get_file(filename,
url,
extract=True,
cache_dir=config.USER_DIR,
cache_subdir=config.USER_DATA_DIR,
verbose=1)
self.lm = kenlm.Model(self.language_model_path)
logger.debug('Loaded language model: %s, spend: %s s' %
(self.language_model_path, str(time.time() - t1)))
# 词、频数dict
t2 = time.time()
self.word_freq = self.load_word_freq_dict(self.word_freq_path)
t3 = time.time()
logger.debug('Loaded word freq file: %s, size: %d, spend: %s s' %
(self.word_freq_path, len(self.word_freq), str(t3 - t2)))
# 自定义混淆集
self.custom_confusion = self._get_custom_confusion_dict(
self.custom_confusion_path)
t4 = time.time()
logger.debug('Loaded confusion file: %s, size: %d, spend: %s s' %
(self.custom_confusion_path, len(
self.custom_confusion), str(t4 - t3)))
# 自定义切词词典
self.custom_word_freq = self.load_word_freq_dict(
self.custom_word_freq_path)
self.person_names = self.load_word_freq_dict(self.person_name_path)
self.place_names = self.load_word_freq_dict(self.place_name_path)
self.stopwords = self.load_word_freq_dict(self.stopwords_path)
# 合并切词词典及自定义词典
self.custom_word_freq.update(self.person_names)
self.custom_word_freq.update(self.place_names)
self.custom_word_freq.update(self.stopwords)
self.word_freq.update(self.custom_word_freq)
t5 = time.time()
logger.debug('Loaded custom word file: %s, size: %d, spend: %s s' %
(self.custom_word_freq_path, len(
self.custom_word_freq), str(t5 - t4)))
self.tokenizer = Tokenizer(dict_path=self.word_freq_path,
custom_word_freq_dict=self.custom_word_freq,
custom_confusion_dict=self.custom_confusion)
self.initialized_detector = True
def test_tokenizer():
txts = [
"我不要你花钱,这些路曲近通幽", "这个消息不胫儿走", "这个消息不径而走", "这个消息不胫而走", "复方甘草口服溶液限田基",
"张老师经常背课到深夜，我们要体晾老师的心苦。", '新进人员时，知识当然还不过，可是人有很有精神，面对工作很认真的话，很快就学会、体会。',
"小牛曲清去蛋白提取物乙"
]
t = Tokenizer()
for text in txts:
print(text)
print('deault', t.tokenize(text, 'default'))
print('search', t.tokenize(text, 'search'))
print('ngram', t.tokenize(text, 'ngram'))
def test_tokenizer():
txts = [
"我不要你花钱,这些路曲近通幽", "这个消息不胫儿走", "这个消息不径而走", "这个消息不胫而走", "复方甘草口服溶液限田基",
"张老师经常背课到深夜，我们要体晾老师的心苦。", '新进人员时，知识当然还不过，可是人有很有精神，面对工作很认真的话，很快就学会、体会。',
",我遇到了问题怎么办", ",我遇到了问题", "问题", "北川景子参演了林诣彬导演的《速度与激情3》",
"林志玲亮相网友:确定不是波多野结衣？", "龟山千广和近藤公园在龟山公园里喝酒赏花", "小牛曲清去蛋白提取物乙"
]
t = Tokenizer()
for text in txts:
print(text)
print('deault', t.tokenize(text, 'default'))
print('search', t.tokenize(text, 'search'))
print('ngram', t.tokenize(text, 'ngram'))
def set_custom_word_freq(self, path):
self.check_detector_initialized()
word_freqs = self.load_word_freq_dict(path)
# 合并字典
self.custom_word_freq.update(word_freqs)
# 合并切词词典及自定义词典
self.word_freq.update(self.custom_word_freq)
self.tokenizer = Tokenizer(dict_path=self.word_freq_path,
custom_word_freq_dict=self.custom_word_freq,
custom_confusion_dict=self.custom_confusion)
for k, v in word_freqs.items():
self.set_word_frequency(k, v)
logger.debug('Loaded custom word path: %s, size: %d' %
(path, len(word_freqs)))
class Detector(object):
pre_trained_language_models = {
# 语言模型 2.95GB
'zh_giga.no_cna_cmn.prune01244.klm':
'https://deepspeech.bj.bcebos.com/zh_lm/zh_giga.no_cna_cmn.prune01244.klm',
# 人民日报训练语言模型 20MB
'people_chars_lm.klm':
'https://www.borntowin.cn/mm/emb_models/people_chars_lm.klm'
}
def __init__(self,
language_model_path=config.language_model_path,
word_freq_path=config.word_freq_path,
custom_word_freq_path='',
custom_confusion_path='',
person_name_path=config.person_name_path,
place_name_path=config.place_name_path,
stopwords_path=config.stopwords_path):
self.name = 'detector'
self.language_model_path = language_model_path
self.word_freq_path = word_freq_path
self.custom_word_freq_path = custom_word_freq_path
self.custom_confusion_path = custom_confusion_path
self.person_name_path = person_name_path
self.place_name_path = place_name_path
self.stopwords_path = stopwords_path
self.is_char_error_detect = True
self.is_word_error_detect = True
self.initialized_detector = False
self.lm = None
self.word_freq = None
self.custom_confusion = None
self.custom_word_freq = None
self.person_names = None
self.place_names = None
self.stopwords = None
self.tokenizer = None
def _initialize_detector(self):
t1 = time.time()
try:
import kenlm
except ImportError:
raise ImportError(
'pycorrector dependencies are not fully installed, '
'they are required for statistical language model.'
'Please use "pip install kenlm" to install it.'
'if you are Win, Please install kenlm in cgwin.')
if not os.path.exists(self.language_model_path):
filename = self.pre_trained_language_models.get(
self.language_model_path, 'zh_giga.no_cna_cmn.prune01244.klm')
url = self.pre_trained_language_models.get(filename)
get_file(filename,
url,
extract=True,
cache_dir='~',
cache_subdir=config.USER_DATA_DIR,
verbose=1)
self.lm = kenlm.Model(self.language_model_path)
t2 = time.time()
logger.debug('Loaded language model: %s, spend: %.3f s.' %
(self.language_model_path, t2 - t1))
# 词、频数dict
self.word_freq = self.load_word_freq_dict(self.word_freq_path)
# 自定义混淆集
self.custom_confusion = self._get_custom_confusion_dict(
self.custom_confusion_path)
# 自定义切词词典
self.custom_word_freq = self.load_word_freq_dict(
self.custom_word_freq_path)
self.person_names = self.load_word_freq_dict(self.person_name_path)
self.place_names = self.load_word_freq_dict(self.place_name_path)
self.stopwords = self.load_word_freq_dict(self.stopwords_path)
# 合并切词词典及自定义词典
self.custom_word_freq.update(self.person_names)
self.custom_word_freq.update(self.place_names)
self.custom_word_freq.update(self.stopwords)
self.word_freq.update(self.custom_word_freq)
self.tokenizer = Tokenizer(dict_path=self.word_freq_path,
custom_word_freq_dict=self.custom_word_freq,
custom_confusion_dict=self.custom_confusion)
t3 = time.time()
logger.debug('Loaded dict file, spend: %.3f s.' % (t3 - t2))
self.initialized_detector = True
def check_detector_initialized(self):
if not self.initialized_detector:
self._initialize_detector()
@staticmethod
def load_word_freq_dict(path):
"""
加载切词词典
:param path:
:return:
"""
word_freq = {}
if path:
if not os.path.exists(path):
logger.warning('file not found.%s' % path)
return word_freq
else:
with codecs.open(path, 'r', encoding='utf-8') as f:
for line in f:
line = line.strip()
if line.startswith('#'):
continue
info = line.split()
if len(info) < 1:
continue
word = info[0]
# 取词频，默认1
freq = int(info[1]) if len(info) > 1 else 1
word_freq[word] = freq
return word_freq
def _get_custom_confusion_dict(self, path):
"""
取自定义困惑集
:param path:
:return: dict, {variant: origin}, eg: {"交通先行": "交通限行"}
"""
confusion = {}
if path:
if not os.path.exists(path):
logger.warning('file not found.%s' % path)
return confusion
else:
with codecs.open(path, 'r', encoding='utf-8') as f:
for line in f:
line = line.strip()
if line.startswith('#'):
continue
info = line.split()
if len(info) < 2:
continue
variant = info[0]
origin = info[1]
freq = int(info[2]) if len(info) > 2 else 1
self.word_freq[origin] = freq
confusion[variant] = origin
return confusion
def set_language_model_path(self, path):
self.check_detector_initialized()
import kenlm
self.lm = kenlm.Model(path)
logger.debug('Loaded language model: %s' % path)
def set_custom_confusion_dict(self, path):
self.check_detector_initialized()
self.custom_confusion = self._get_custom_confusion_dict(path)
logger.debug('Loaded confusion path: %s, size: %d' %
(path, len(self.custom_confusion)))
def set_custom_word_freq(self, path):
self.check_detector_initialized()
word_freqs = self.load_word_freq_dict(path)
# 合并字典
self.custom_word_freq.update(word_freqs)
# 合并切词词典及自定义词典
self.word_freq.update(self.custom_word_freq)
self.tokenizer = Tokenizer(dict_path=self.word_freq_path,
custom_word_freq_dict=self.custom_word_freq,
custom_confusion_dict=self.custom_confusion)
for k, v in word_freqs.items():
self.set_word_frequency(k, v)
logger.debug('Loaded custom word path: %s, size: %d' %
(path, len(word_freqs)))
def enable_char_error(self, enable=True):
"""
is open char error detect
:param enable:
:return:
"""
self.is_char_error_detect = enable
def enable_word_error(self, enable=True):
"""
is open word error detect
:param enable:
:return:
"""
self.is_word_error_detect = enable
def ngram_score(self, chars):
"""
取n元文法得分
:param chars: list, 以词或字切分
:return:
"""
self.check_detector_initialized()
return self.lm.score(' '.join(chars), bos=False, eos=False)
def ppl_score(self, words):
"""
取语言模型困惑度得分，越小句子越通顺
:param words: list, 以词或字切分
:return:
"""
self.check_detector_initialized()
return self.lm.perplexity(' '.join(words))
def word_frequency(self, word):
"""
取词在样本中的词频
:param word:
:return: dict
"""
self.check_detector_initialized()
return self.word_freq.get(word, 0)
def set_word_frequency(self, word, num):
"""
更新在样本中的词频
"""
self.check_detector_initialized()
self.word_freq[word] = num
return self.word_freq
@staticmethod
def _check_contain_error(maybe_err, maybe_errors):
"""
检测错误集合(maybe_errors)是否已经包含该错误位置（maybe_err)
:param maybe_err: [error_word, begin_pos, end_pos, error_type]
:param maybe_errors:list
:return: bool
"""
error_word_idx = 0
begin_idx = 1
end_idx = 2
for err in maybe_errors:
if maybe_err[error_word_idx] in err[error_word_idx] and maybe_err[begin_idx] >= err[begin_idx] and \
maybe_err[end_idx] <= err[end_idx]:
return True
return False
def _add_maybe_error_item(self, maybe_err, maybe_errors):
"""
新增错误
:param maybe_err:
:param maybe_errors:
:return:
"""
if maybe_err not in maybe_errors and not self._check_contain_error(
maybe_err, maybe_errors):
maybe_errors.append(maybe_err)
@staticmethod
def _get_maybe_error_index(scores, ratio=0.6745, threshold=2):
"""
取疑似错字的位置，通过平均绝对离差（MAD）
:param scores: np.array
:param ratio: 正态分布表参数
:param threshold: 阈值越小，得到疑似错别字越多
:return: 全部疑似错误字的index: list
"""
result = []
scores = np.array(scores)
if len(scores.shape) == 1:
scores = scores[:, None]
median = np.median(scores, axis=0) # get median of all scores
margin_median = np.abs(scores -
median).flatten() # deviation from the median
# 平均绝对离差值
med_abs_deviation = np.median(margin_median)
if med_abs_deviation == 0:
return result
y_score = ratio * margin_median / med_abs_deviation
# 打平
scores = scores.flatten()
maybe_error_indices = np.where((y_score > threshold)
& (scores < median))
# 取全部疑似错误字的index
result = list(maybe_error_indices[0])
return result
@staticmethod
def _get_maybe_error_index_by_stddev(scores, n=2):
"""
取疑似错字的位置，通过平均值上下n倍标准差之间属于正常点
:param scores: list, float
:param n: n倍
:return: 全部疑似错误字的index: list
"""
std = np.std(scores, ddof=1)
mean = np.mean(scores)
down_limit = mean - n * std
upper_limit = mean + n * std
maybe_error_indices = np.where((scores > upper_limit)
| (scores < down_limit))
# 取全部疑似错误字的index
result = list(maybe_error_indices[0])
return result
@staticmethod
def is_filter_token(token):
"""
是否为需过滤字词
:param token: 字词
:return: bool
"""
result = False
# pass blank
if not token.strip():
result = True
# pass num
if token.isdigit():
result = True
# pass alpha
if is_alphabet_string(token.lower()):
result = True
# pass not chinese
if not is_chinese_string(token):
result = True
return result
@staticmethod
def split_2_short_text(text, include_symbol=False):
"""
长句切分为短句
:param text: str
:param include_symbol: bool
:return: (sentence, idx)
"""
result = []
blocks = re_han.split(text)
start_idx = 0
for blk in blocks:
if not blk:
continue
if include_symbol:
result.append((blk, start_idx))
else:
if re_han.match(blk):
result.append((blk, start_idx))
start_idx += len(blk)
return result
@staticmethod
def split_text_by_maxlen(text, maxlen=512):
"""
长句切分为短句，每个短句maxlen个字
:param text: str
:param maxlen: int, 最大长度
:return: list, (sentence, idx)
"""
result = []
for i in range(0, len(text), maxlen):
result.append((text[i:i + maxlen], i))
return result
def detect(self, text):
"""
文本错误检测
:param text: 长文本
:return: 错误index
"""
maybe_errors = []
if not text.strip():
return maybe_errors
# 初始化
self.check_detector_initialized()
# 编码统一，utf-8 to unicode
text = convert_to_unicode(text)
# 文本归一化
text = uniform(text)
# 长句切分为短句
blocks = self.split_2_short_text(text)
for blk, idx in blocks:
maybe_errors += self.detect_short(blk, idx)
return maybe_errors
def detect_short(self, sentence, start_idx=0):
"""
检测句子中的疑似错误信息，包括[词、位置、错误类型]
:param sentence:
:param start_idx:
:return: list[list], [error_word, begin_pos, end_pos, error_type]
"""
maybe_errors = []
# 初始化
self.check_detector_initialized()
# 自定义混淆集加入疑似错误词典
for confuse in self.custom_confusion:
idx = sentence.find(confuse)
if idx > -1:
maybe_err = [
confuse, idx + start_idx, idx + len(confuse) + start_idx,
ErrorType.confusion
]
self._add_maybe_error_item(maybe_err, maybe_errors)
if self.is_word_error_detect:
# 切词
tokens = self.tokenizer.tokenize(sentence)
# 未登录词加入疑似错误词典
for token, begin_idx, end_idx in tokens:
# pass filter word
if self.is_filter_token(token):
continue
# pass in dict
if token in self.word_freq:
continue
maybe_err = [
token, begin_idx + start_idx, end_idx + start_idx,
ErrorType.word
]
self._add_maybe_error_item(maybe_err, maybe_errors)
if self.is_char_error_detect:
# 语言模型检测疑似错误字
try:
ngram_avg_scores = []
for n in [2, 3]:
scores = []
for i in range(len(sentence) - n + 1):
word = sentence[i:i + n]
score = self.ngram_score(list(word))
scores.append(score)
if not scores:
continue
# 移动窗口补全得分
for _ in range(n - 1):
scores.insert(0, scores[0])
scores.append(scores[-1])
avg_scores = [
sum(scores[i:i + n]) / len(scores[i:i + n])
for i in range(len(sentence))
]
ngram_avg_scores.append(avg_scores)
if ngram_avg_scores:
# 取拼接后的n-gram平均得分
sent_scores = list(
np.average(np.array(ngram_avg_scores), axis=0))
# 取疑似错字信息
for i in self._get_maybe_error_index(sent_scores):
token = sentence[i]
# pass filter word
if self.is_filter_token(token):
continue
# pass in stop word dict
if token in self.stopwords:
continue
# token, begin_idx, end_idx, error_type
maybe_err = [
token, i + start_idx, i + start_idx + 1,
ErrorType.char
]
self._add_maybe_error_item(maybe_err, maybe_errors)
except IndexError as ie:
logger.warn("index error, sentence:" + sentence + str(ie))
except Exception as e:
logger.warn("detect error, sentence:" + sentence + str(e))
return sorted(maybe_errors, key=lambda k: k[1], reverse=False)
