深度学习简介
深度学习的资料很多，这里就不展开了讲，本文就介绍中文NLP的序列标注工作的一般方法。
机器学习与深度学习
简单来说，机器学习就是根据样本(即数据)学习得到一个模型，再根据这个模型预测的一种方法。
ML算法很多，Naive Bayes朴素贝叶斯、Decision Tree决策树、Support Vector Machine支持向量机、Logistic Regression逻辑回归、Conditional Random Field条件随机场等。
而深度学习，简单来说是一种有多层隐层的感知机。
DL也分很多模型，但一般了解Convolution Neural Network卷积神经网络、Recurrent Neural Network循环神经网络就够了(当然都要学，这里是指前期学习阶段可以侧重这两个)。
异同：ML是一种浅层学习，一般来说都由人工设计特征，而DL则用pre-training或者无监督学习来抽取特征表示，再使用监督学习来训练预测模型（当然不全都是这样）。
本文主要用于介绍DL在中文NLP的应用，所以采用了使用最为简单、方便的DL框架keras来开发，它是构建于两个非常受欢迎的DL框架theano和tensorflow之上的上层应用框架。
NLP简介
Natural Language Process自然语言处理又分为NLU自然语言理解和NLG自然语言生成。而分词、词性标注、实体识别、依存分析则是NLP的基础工作，它们都可以理解为一种序列标注工作。
序列标注工作简介
词向量简介
Word Embedding词向量方法，用实数向量来表示一个词的方法，是对One-hot Representation的一种优化。优点是低维，而且可以方便的用数学距离衡量词的词义相似度，缺点是词一多，模型就有点大，所以又有工作提出了Char Embedding方法，这种方法训练出来的模型很小，但丢失了很多的语义信息，所以又有基于分词信息的字向量的研究工作。
中文NLP序列标注之CWS
CWS简介
Chinese Word Segmentation中文分词是中文NLP的基础，一般来说中文分词有两种方法，一种是基于词典的方法，一种是基于ML或者DL的方法。CWS的发展可以参考漫话中文分词，简单来说基于词典的方法实现简单、速度快，但是对歧义和未登录词没有什么好的办法，而基于ML和DL的方法实现复杂、速度较慢，但是可以较好地应对歧义和OOV(Out-Of-Vocabulary)。
基于词典的方法应用最广的应该是正向最大匹配，而基于ML的CWS效果比较好的算法是CRF，本文主要介绍基于DL的方法，但在实际应用中应该合理的结合两种方法。
标注集与评估方法
这里采用B(Begin字为词的起始)、M(Middle字为词的中间)、E(End字为词的结束)、S(Single单字词)标注集，训练预料和评估工具采用SIGHAN中的方法，具体可以参考我的另一篇文章SIGHAN测评中文分词的方法与指标介绍。
模型
原理是采用bi-directional LSTM模型训练后对句子进行预测得到一个标注的概率，再使用Viterbi算法寻找最优的标注序列。在分词的工作中不需要加入词向量，提升效果不明显。
实现
预处理
#!/usr/bin/env python
#-*- coding: utf-8 -*-
#2016年 03月 03日 星期四 11:01:05 CST by Demobin
import json
import h5py
import string
import codecs
corpus_tags = ['S', 'B', 'M', 'E']
def saveCwsInfo(path, cwsInfo):
'''保存分词训练数据字典和概率'''
print('save cws info to %s'%path)
fd = open(path, 'w')
(initProb, tranProb), (vocab, indexVocab) = cwsInfo
j = json.dumps((initProb, tranProb))
fd.write(j + '\n')
for char in vocab:
fd.write(char.encode('utf-8') + '\t' + str(vocab[char]) + '\n')
fd.close()
def loadCwsInfo(path):
'''载入分词训练数据字典和概率'''
print('load cws info from %s'%path)
fd = open(path, 'r')
line = fd.readline()
j = json.loads(line.strip())
initProb, tranProb = j[0], j[1]
lines = fd.readlines()
fd.close()
vocab = {}
indexVocab = [0 for i in range(len(lines))]
for line in lines:
rst = line.strip().split('\t')
if len(rst) < 2: continue
char, index = rst[0].decode('utf-8'), int(rst[1])
vocab[char] = index
indexVocab[index] = char
return (initProb, tranProb), (vocab, indexVocab)
def saveCwsData(path, cwsData):
'''保存分词训练输入样本'''
print('save cws data to %s'%path)
#采用hdf5保存大矩阵效率最高
fd = h5py.File(path,'w')
(X, y) = cwsData
fd.create_dataset('X', data = X)
fd.create_dataset('y', data = y)
fd.close()
def loadCwsData(path):
'''载入分词训练输入样本'''
print('load cws data from %s'%path)
fd = h5py.File(path,'r')
X = fd['X'][:]
y = fd['y'][:]
fd.close()
return (X, y)
def sent2vec2(sent, vocab, ctxWindows = 5):
charVec = []
for char in sent:
if char in vocab:
charVec.append(vocab[char])
else:
charVec.append(vocab['retain-unknown'])
#首尾padding
num = len(charVec)
pad = int((ctxWindows - 1)/2)
for i in range(pad):
charVec.insert(0, vocab['retain-padding'] )
charVec.append(vocab['retain-padding'] )
X = []
for i in range(num):
X.append(charVec[i:i + ctxWindows])
return X
def sent2vec(sent, vocab, ctxWindows = 5):
chars = []
for char in sent:
chars.append(char)
return sent2vec2(chars, vocab, ctxWindows = ctxWindows)
def doc2vec(fname, vocab):
'''文档转向量'''
#一次性读入文件，注意内存
fd = codecs.open(fname, 'r', 'utf-8')
lines = fd.readlines()
fd.close()
#样本集
X = []
y = []
#标注统计信息
tagSize = len(corpus_tags)
tagCnt = [0 for i in range(tagSize)]
tagTranCnt = [[0 for i in range(tagSize)] for j in range(tagSize)]
#遍历行
for line in lines:
#按空格分割
words = line.strip('\n').split()
#每行的分词信息
chars = []
tags = []
#遍历词
for word in words:
#包含两个字及以上的词
if len(word) > 1:
#词的首字
chars.append(word[0])
tags.append(corpus_tags.index('B'))
#词中间的字
for char in word[1:(len(word) - 1)]:
chars.append(char)
tags.append(corpus_tags.index('M'))
#词的尾字
chars.append(word[-1])
tags.append(corpus_tags.index('E'))
#单字词
else:
chars.append(word)
tags.append(corpus_tags.index('S'))
#字向量表示
lineVecX = sent2vec2(chars, vocab, ctxWindows = 7)
#统计标注信息
lineVecY = []
lastTag = -1
for tag in tags:
#向量
lineVecY.append(tag)
#lineVecY.append(corpus_tags[tag])
#统计tag频次
tagCnt[tag] += 1
#统计tag转移频次
if lastTag != -1:
tagTranCnt[lastTag][tag] += 1
#暂存上一次的tag
lastTag = tag
X.extend(lineVecX)
y.extend(lineVecY)
#字总频次
charCnt = sum(tagCnt)
#转移总频次
tranCnt = sum([sum(tag) for tag in tagTranCnt])
#tag初始概率
initProb = []
for i in range(tagSize):
initProb.append(tagCnt[i]/float(charCnt))
#tag转移概率
tranProb = []
for i in range(tagSize):
p = []
for j in range(tagSize):
p.append(tagTranCnt[i][j]/float(tranCnt))
tranProb.append(p)
return X, y, initProb, tranProb
def genVocab(fname, delimiters = [' ', '\n']):
#一次性读入文件，注意内存
fd = codecs.open(fname, 'r', 'utf-8')
data = fd.read()
fd.close()
vocab = {}
indexVocab = []
#遍历
index = 0
for char in data:
#如果为分隔符则无需加入字典
if char not in delimiters and char not in vocab:
vocab[char] = index
indexVocab.append(char)
index += 1
#加入未登陆新词和填充词
vocab['retain-unknown'] = len(vocab)
vocab['retain-padding'] = len(vocab)
indexVocab.append('retain-unknown')
indexVocab.append('retain-padding')
#返回字典与索引
return vocab, indexVocab
def load(fname):
print 'train from file', fname
delims = [' ', '\n']
vocab, indexVocab = genVocab(fname)
X, y, initProb, tranProb = doc2vec(fname, vocab)
print len(X), len(y), len(vocab), len(indexVocab)
print initProb
print tranProb
return (X, y), (initProb, tranProb), (vocab, indexVocab)
if __name__ == '__main__':
load('~/work/corpus/icwb2/training/msr_training.utf8')
模型
#!/usr/bin/env python
#-*- coding: utf-8 -*-
#2016年 03月 03日 星期四 11:01:05 CST by Demobin
import numpy as np
import json
import h5py
import codecs
from dataset import cws
from util import viterbi
from sklearn.model_selection import train_test_split
from keras.preprocessing import sequence
from keras.optimizers import SGD, RMSprop, Adagrad
from keras.utils import np_utils
from keras.models import Sequential,Graph, model_from_json
from keras.layers.core import Dense, Dropout, Activation, TimeDistributedDense
from keras.layers.embeddings import Embedding
from keras.layers.recurrent import LSTM, GRU, SimpleRNN
from gensim.models import Word2Vec
def train(cwsInfo, cwsData, modelPath, weightPath):
(initProb, tranProb), (vocab, indexVocab) = cwsInfo
(X, y) = cwsData
train_X, test_X, train_y, test_y = train_test_split(X, y , train_size=0.9, random_state=1)
train_X = np.array(train_X)
train_y = np.array(train_y)
test_X = np.array(test_X)
test_y = np.array(test_y)
outputDims = len(cws.corpus_tags)
Y_train = np_utils.to_categorical(train_y, outputDims)
Y_test = np_utils.to_categorical(test_y, outputDims)
batchSize = 128
vocabSize = len(vocab) + 1
wordDims = 100
maxlen = 7
hiddenDims = 100
w2vModel = Word2Vec.load('model/sougou.char.model')
embeddingDim = w2vModel.vector_size
embeddingUnknown = [0 for i in range(embeddingDim)]
embeddingWeights = np.zeros((vocabSize + 1, embeddingDim))
for word, index in vocab.items():
if word in w2vModel:
e = w2vModel[word]
else:
e = embeddingUnknown
embeddingWeights[index, :] = e
#LSTM
model = Sequential()
model.add(Embedding(output_dim = embeddingDim, input_dim = vocabSize + 1,
input_length = maxlen, mask_zero = True, weights = [embeddingWeights]))
model.add(LSTM(output_dim = hiddenDims, return_sequences = True))
model.add(LSTM(output_dim = hiddenDims, return_sequences = False))
model.add(Dropout(0.5))
model.add(Dense(outputDims))
model.add(Activation('softmax'))
model.compile(loss = 'categorical_crossentropy', optimizer = 'adam')
result = model.fit(train_X, Y_train, batch_size = batchSize,
nb_epoch = 20, validation_data = (test_X,Y_test), show_accuracy=True)
j = model.to_json()
fd = open(modelPath, 'w')
fd.write(j)
fd.close()
model.save_weights(weightPath)
return model
def loadModel(modelPath, weightPath):
fd = open(modelPath, 'r')
j = fd.read()
fd.close()
model = model_from_json(j)
model.load_weights(weightPath)
return model
# 根据输入得到标注推断
def cwsSent(sent, model, cwsInfo):
(initProb, tranProb), (vocab, indexVocab) = cwsInfo
vec = cws.sent2vec(sent, vocab, ctxWindows = 7)
vec = np.array(vec)
probs = model.predict_proba(vec)
#classes = model.predict_classes(vec)
prob, path = viterbi.viterbi(vec, cws.corpus_tags, initProb, tranProb, probs.transpose())
ss = ''
for i, t in enumerate(path):
ss += '%s/%s '%(sent[i], cws.corpus_tags[t])
ss = ''
word = ''
for i, t in enumerate(path):
if cws.corpus_tags[t] == 'S':
ss += sent[i] + ' '
word = ''
elif cws.corpus_tags[t] == 'B':
word += sent[i]
elif cws.corpus_tags[t] == 'E':
word += sent[i]
ss += word + ' '
word = ''
elif cws.corpus_tags[t] == 'M':
word += sent[i]
return ss
def cwsFile(fname, dstname, model, cwsInfo):
fd = codecs.open(fname, 'r', 'utf-8')
lines = fd.readlines()
fd.close()
fd = open(dstname, 'w')
for line in lines:
rst = cwsSent(line.strip(), model, cwsInfo)
fd.write(rst.encode('utf-8') + '\n')
fd.close()
def test():
print 'Loading vocab...'
cwsInfo = cws.loadCwsInfo('./model/cws.info')
cwsData = cws.loadCwsData('./model/cws.data')
print 'Done!'
print 'Loading model...'
#model = train(cwsInfo, cwsData, './model/cws.w2v.model', './model/cws.w2v.model.weights')
#model = loadModel('./model/cws.w2v.model', './model/cws.w2v.model.weights')
model = loadModel('./model/cws.model', './model/cws.model.weights')
print 'Done!'
print '-------------start predict----------------'
#s = u'为寂寞的夜空画上一个月亮'
#print cwsSent(s, model, cwsInfo)
cwsFile('~/work/corpus/icwb2/testing/msr_test.utf8', './msr_test.utf8.cws', model, cwsInfo)
if __name__ == '__main__':
test()
viterbi算法
#!/usr/bin/python
# -*- coding: utf-8 -*-
#2016年 01月 28日 星期四 17:14:03 CST by Demobin
def _print(hiddenstates, V):
s = " " + " ".join(("%7d" % i) for i in range(len(V))) + "\n"
for i, state in enumerate(hiddenstates):
s += "%.5s: " % state
s += " ".join("%.7s" % ("%f" % v[i]) for v in V)
s += "\n"
print(s)
#标准viterbi算法，参数为观察状态、隐藏状态、概率三元组(初始概率、转移概率、观察概率)
def viterbi(obs, states, start_p, trans_p, emit_p):
lenObs = len(obs)
lenStates = len(states)
V = [[0.0 for col in range(lenStates)] for row in range(lenObs)]
path = [[0 for col in range(lenObs)] for row in range(lenStates)]
#t = 0时刻
for y in range(lenStates):
#V[0][y] = start_p[y] * emit_p[y][obs[0]]
V[0][y] = start_p[y] * emit_p[y][0]
path[y][0] = y
#t > 1时
for t in range(1, lenObs):
newpath = [[0.0 for col in range(lenObs)] for row in range(lenStates)]
for y in range(lenStates):
prob = -1
state = 0
for y0 in range(lenStates):
#nprob = V[t - 1][y0] * trans_p[y0][y] * emit_p[y][obs[t]]
nprob = V[t - 1][y0] * trans_p[y0][y] * emit_p[y][t]
if nprob > prob:
prob = nprob
state = y0
#记录最大概率
V[t][y] = prob
#记录路径
newpath[y][:t] = path[state][:t]
newpath[y][t] = y
path = newpath
prob = -1
state = 0
for y in range(lenStates):
if V[lenObs - 1][y] > prob:
prob = V[lenObs - 1][y]
state = y
#_print(states, V)
return prob, path[state]
def example():
#隐藏状态
hiddenstates = ('Healthy', 'Fever')
#观察状态
observations = ('normal', 'cold', 'dizzy')
#初始概率
'''
Healthy': 0.6, 'Fever': 0.4
'''
start_p = [0.6, 0.4]
#转移概率
'''
Healthy' : {'Healthy': 0.7, 'Fever': 0.3},
Fever' : {'Healthy': 0.4, 'Fever': 0.6}
'''
trans_p = [[0.7, 0.3], [0.4, 0.6]]
#发射概率/输出概率/观察概率
'''
Healthy' : {'normal': 0.5, 'cold': 0.4, 'dizzy': 0.1},
Fever' : {'normal': 0.1, 'cold': 0.3, 'dizzy': 0.6}
'''
emit_p = [[0.5, 0.4, 0.1], [0.1, 0.3, 0.6]]
return viterbi(observations,
hiddenstates,
start_p,
trans_p,
emit_p)
if __name__ == '__main__':
print(example())
中文NLP序列标注之POS
预处理
#!/usr/bin/env python
# -*- coding: utf-8 -*-
#2016年 03月 03日 星期四 11:01:05 CST by Demobin
import h5py
import json
import codecs
mappings = {
#人民日报标注集：863标注集
'w': 'wp',
't': 'nt',
'nr': 'nh',
'nx': 'nz',
'nn': 'n',
'nzz': 'n',
'Ng': 'n',
'f': 'nd',
's': 'nl',
'Vg': 'v',
'vd': 'v',
'vn': 'v',
'vnn': 'v',
'ad': 'a',
'an': 'a',
'Ag': 'a',
'l': 'i',
'z': 'a',
'mq': 'm',
'Mg': 'm',
'Tg': 'nt',
'y': 'u',
'Yg': 'u',
'Dg': 'd',
'Rg': 'r',
'Bg': 'b',
'pn': 'p',
}
tags_863 = {
'a' : [0, '形容词'],
'b' : [1, '区别词'],
'c' : [2, '连词'],
'd' : [3, '副词'],
'e' : [4, '叹词'],
'g' : [5, '语素字'],
'h' : [6, '前接成分'],
'i' : [7, '习用语'],
'j' : [8, '简称'],
'k' : [9, '后接成分'],
'm' : [10, '数词'],
'n' : [11, '名词'],
'nd': [12, '方位名词'],
'nh': [13, '人名'],
'ni': [14, '团体、机构、组织的专名'],
'nl': [15, '处所名词'],
'ns': [16, '地名'],
'nt': [17, '时间名词'],
'nz': [18, '其它专名'],
'o' : [19, '拟声词'],
'p' : [20, '介词'],
'q' : [21, '量词'],
'r' : [22, '代词'],
'u' : [23, '助词'],
'v' : [24, '动词'],
'wp': [25, '标点'],
'ws': [26, '字符串'],
'x' : [27, '非语素字'],
}
def genCorpusTags():
s = ''
features = ['b', 'm', 'e', 's']
for tag in tags:
for f in features:
s += '\'' + tag + '-' + f + '\'' + ','
print s
corpus_tags = [
'nh-b','nh-m','nh-e','nh-s','ni-b','ni-m','ni-e','ni-s','nl-b','nl-m','nl-e','nl-s','nd-b','nd-m','nd-e','nd-s','nz-b','nz-m','nz-e','nz-s','ns-b','ns-m','ns-e','ns-s','nt-b','nt-m','nt-e','nt-s','ws-b','ws-m','ws-e','ws-s','wp-b','wp-m','wp-e','wp-s','a-b','a-m','a-e','a-s','c-b','c-m','c-e','c-s','b-b','b-m','b-e','b-s','e-b','e-m','e-e','e-s','d-b','d-m','d-e','d-s','g-b','g-m','g-e','g-s','i-b','i-m','i-e','i-s','h-b','h-m','h-e','h-s','k-b','k-m','k-e','k-s','j-b','j-m','j-e','j-s','m-b','m-m','m-e','m-s','o-b','o-m','o-e','o-s','n-b','n-m','n-e','n-s','q-b','q-m','q-e','q-s','p-b','p-m','p-e','p-s','r-b','r-m','r-e','r-s','u-b','u-m','u-e','u-s','v-b','v-m','v-e','v-s','x-b','x-m','x-e','x-s'
]
def savePosInfo(path, posInfo):
'''保存分词训练数据字典和概率'''
print('save pos info to %s'%path)
fd = open(path, 'w')
(initProb, tranProb), (vocab, indexVocab) = posInfo
j = json.dumps((initProb, tranProb))
fd.write(j + '\n')
for char in vocab:
fd.write(char.encode('utf-8') + '\t' + str(vocab[char]) + '\n')
fd.close()
def loadPosInfo(path):
'''载入分词训练数据字典和概率'''
print('load pos info from %s'%path)
fd = open(path, 'r')
line = fd.readline()
j = json.loads(line.strip())
initProb, tranProb = j[0], j[1]
lines = fd.readlines()
fd.close()
vocab = {}
indexVocab = [0 for i in range(len(lines))]
for line in lines:
rst = line.strip().split('\t')
if len(rst) < 2: continue
char, index = rst[0].decode('utf-8'), int(rst[1])
vocab[char] = index
indexVocab[index] = char
return (initProb, tranProb), (vocab, indexVocab)
def savePosData(path, posData):
'''保存分词训练输入样本'''
print('save pos data to %s'%path)
#采用hdf5保存大矩阵效率最高
fd = h5py.File(path,'w')
(X, y) = posData
fd.create_dataset('X', data = X)
fd.create_dataset('y', data = y)
fd.close()
def loadPosData(path):
'''载入分词训练输入样本'''
print('load pos data from %s'%path)
fd = h5py.File(path,'r')
X = fd['X'][:]
y = fd['y'][:]
fd.close()
return (X, y)
def sent2vec2(sent, vocab, ctxWindows = 5):
charVec = []
for char in sent:
if char in vocab:
charVec.append(vocab[char])
else:
charVec.append(vocab['retain-unknown'])
#首尾padding
num = len(charVec)
pad = int((ctxWindows - 1)/2)
for i in range(pad):
charVec.insert(0, vocab['retain-padding'] )
charVec.append(vocab['retain-padding'] )
X = []
for i in range(num):
X.append(charVec[i:i + ctxWindows])
return X
def sent2vec(sent, vocab, ctxWindows = 5):
chars = []
words = sent.split()
for word in words:
#包含两个字及以上的词
if len(word) > 1:
#词的首字
chars.append(word[0] + '_b')
#词中间的字
for char in word[1:(len(word) - 1)]:
chars.append(char + '_m')
#词的尾字
chars.append(word[-1] + '_e')
#单字词
else:
chars.append(word + '_s')
return sent2vec2(chars, vocab, ctxWindows = ctxWindows)
def doc2vec(fname, vocab):
'''文档转向量'''
#一次性读入文件，注意内存
fd = codecs.open(fname, 'r', 'utf-8')
lines = fd.readlines()
fd.close()
#样本集
X = []
y = []
#标注统计信息
tagSize = len(corpus_tags)
tagCnt = [0 for i in range(tagSize)]
tagTranCnt = [[0 for i in range(tagSize)] for j in range(tagSize)]
#遍历行
for line in lines:
#按空格分割
words = line.strip('\n').split()
#每行的分词信息
chars = []
tags = []
#遍历词
for word in words:
rst = word.split('/')
if len(rst) <= 0:
print word
continue
word, tag = rst[0], rst[1].decode('utf-8')
if tag not in tags_863:
tag = mappings[tag]
#包含两个字及以上的词
if len(word) > 1:
#词的首字
chars.append(word[0] + '_b')
tags.append(corpus_tags.index(tag + '-' + 'b'))
#词中间的字
for char in word[1:(len(word) - 1)]:
chars.append(char + '_m')
tags.append(corpus_tags.index(tag + '-' + 'm'))
#词的尾字
chars.append(word[-1] + '_e')
tags.append(corpus_tags.index(tag + '-' + 'e'))
#单字词
else:
chars.append(word + '_s')
tags.append(corpus_tags.index(tag + '-' + 's'))
#字向量表示
lineVecX = sent2vec2(chars, vocab, ctxWindows = 7)
#统计标注信息
lineVecY = []
lastTag = -1
for tag in tags:
#向量
lineVecY.append(tag)
#lineVecY.append(corpus_tags[tag])
#统计tag频次
tagCnt[tag] += 1
#统计tag转移频次
if lastTag != -1:
tagTranCnt[lastTag][tag] += 1
#暂存上一次的tag
lastTag = tag
X.extend(lineVecX)
y.extend(lineVecY)
#字总频次
charCnt = sum(tagCnt)
#转移总频次
tranCnt = sum([sum(tag) for tag in tagTranCnt])
#tag初始概率
initProb = []
for i in range(tagSize):
initProb.append(tagCnt[i]/float(charCnt))
#tag转移概率
tranProb = []
for i in range(tagSize):
p = []
for j in range(tagSize):
p.append(tagTranCnt[i][j]/float(tranCnt))
tranProb.append(p)
return X, y, initProb, tranProb
def vocabAddChar(vocab, indexVocab, index, char):
if char not in vocab:
vocab[char] = index
indexVocab.append(char)
index += 1
return index
def genVocab(fname, delimiters = [' ', '\n']):
#一次性读入文件，注意内存
fd = codecs.open(fname, 'r', 'utf-8')
lines = fd.readlines()
fd.close()
vocab = {}
indexVocab = []
#遍历所有行
index = 0
for line in lines:
words = line.strip().split()
if words <= 0: continue
#遍历所有词
for word in words:
word, tag = word.split('/')
#包含两个字及以上的词
if len(word) > 1:
#词的首字
char = word[0] + '_b'
index = vocabAddChar(vocab, indexVocab, index, char)
#词中间的字
for char in word[1:(len(word) - 1)]:
char = char + '_m'
index = vocabAddChar(vocab, indexVocab, index, char)
#词的尾字
char = word[-1] + '_e'
index = vocabAddChar(vocab, indexVocab, index, char)
#单字词
else:
char = word + '_s'
index = vocabAddChar(vocab, indexVocab, index, char)
#加入未登陆新词和填充词
vocab['retain-unknown'] = len(vocab)
vocab['retain-padding'] = len(vocab)
indexVocab.append('retain-unknown')
indexVocab.append('retain-padding')
#返回字典与索引
return vocab, indexVocab
def load(fname):
print 'train from file', fname
delims = [' ', '\n']
vocab, indexVocab = genVocab(fname)
X, y, initProb, tranProb = doc2vec(fname, vocab)
print len(X), len(y), len(vocab), len(indexVocab)
print initProb
print tranProb
return (X, y), (initProb, tranProb), (vocab, indexVocab)
def test():
load('../data/pos.train')
if __name__ == '__main__':
test()
模型
#!/usr/bin/env python
#-*- coding: utf-8 -*-
#2016年 03月 03日 星期四 11:01:05 CST by Demobin
import numpy as np
import json
import h5py
import codecs
from dataset import pos
from util import viterbi
from sklearn.model_selection import train_test_split
from keras.preprocessing import sequence
from keras.optimizers import SGD, RMSprop, Adagrad
from keras.utils import np_utils
from keras.models import Sequential,Graph, model_from_json
from keras.layers.core import Dense, Dropout, Activation, TimeDistributedDense
from keras.layers.embeddings import Embedding
from keras.layers.recurrent import LSTM, GRU, SimpleRNN
from util import pChar
def train(posInfo, posData, modelPath, weightPath):
(initProb, tranProb), (vocab, indexVocab) = posInfo
(X, y) = posData
train_X, test_X, train_y, test_y = train_test_split(X, y , train_size=0.9, random_state=1)
train_X = np.array(train_X)
train_y = np.array(train_y)
test_X = np.array(test_X)
test_y = np.array(test_y)
outputDims = len(pos.corpus_tags)
Y_train = np_utils.to_categorical(train_y, outputDims)
Y_test = np_utils.to_categorical(test_y, outputDims)
batchSize = 128
vocabSize = len(vocab) + 1
wordDims = 100
maxlen = 7
hiddenDims = 100
w2vModel, vectorSize = pChar.load('model/pChar.model')
embeddingDim = int(vectorSize)
embeddingUnknown = [0 for i in range(embeddingDim)]
embeddingWeights = np.zeros((vocabSize + 1, embeddingDim))
for word, index in vocab.items():
if word in w2vModel:
e = w2vModel[word]
else:
print word
e = embeddingUnknown
embeddingWeights[index, :] = e
#LSTM
model = Sequential()
model.add(Embedding(output_dim = embeddingDim, input_dim = vocabSize + 1,
input_length = maxlen, mask_zero = True, weights = [embeddingWeights]))
model.add(LSTM(output_dim = hiddenDims, return_sequences = True))
model.add(LSTM(output_dim = hiddenDims, return_sequences = False))
model.add(Dropout(0.5))
model.add(Dense(outputDims))
model.add(Activation('softmax'))
model.compile(loss = 'categorical_crossentropy', optimizer = 'adam')
result = model.fit(train_X, Y_train, batch_size = batchSize,
nb_epoch = 20, validation_data = (test_X,Y_test), show_accuracy=True)
j = model.to_json()
fd = open(modelPath, 'w')
fd.write(j)
fd.close()
model.save_weights(weightPath)
return model
#Bi-directional LSTM
def loadModel(modelPath, weightPath):
fd = open(modelPath, 'r')
j = fd.read()
fd.close()
model = model_from_json(j)
model.load_weights(weightPath)
return model
# 根据输入得到标注推断
def posSent(sent, model, posInfo):
(initProb, tranProb), (vocab, indexVocab) = posInfo
vec = pos.sent2vec(sent, vocab, ctxWindows = 7)
vec = np.array(vec)
probs = model.predict_proba(vec)
#classes = model.predict_classes(vec)
prob, path = viterbi.viterbi(vec, pos.corpus_tags, initProb, tranProb, probs.transpose())
ss = ''
words = sent.split()
index = -1
for word in words:
for char in word:
index += 1
ss += word + '/' + pos.tags_863[pos.corpus_tags[path[index]][:-2]][1].decode('utf-8') + ' '
#ss += word + '/' + pos.corpus_tags[path[index]][:-2] + ' '
return ss[:-1]
def posFile(fname, dstname, model, posInfo):
fd = codecs.open(fname, 'r', 'utf-8')
lines = fd.readlines()
fd.close()
fd = open(dstname, 'w')
for line in lines:
rst = posSent(line.strip(), model, posInfo)
fd.write(rst.encode('utf-8') + '\n')
fd.close()
def test():
print 'Loading vocab...'
#(X, y), (initProb, tranProb), (vocab, indexVocab) = pos.load('data/pos.train')
#posInfo = ((initProb, tranProb), (vocab, indexVocab))
#posData = (X, y)
#pos.savePosInfo('./model/pos.info', posInfo)
#pos.savePosData('./model/pos.data', posData)
posInfo = pos.loadPosInfo('./model/pos.info')
posData = pos.loadPosData('./model/pos.data')
print 'Done!'
print 'Loading model...'
#model = train(posInfo, posData, './model/pos.w2v.model', './model/pos.w2v.model.weights')
model = loadModel('./model/pos.w2v.model', './model/pos.w2v.model.weights')
#model = loadModel('./model/pos.model', './model/pos.model.weights')
print 'Done!'
print '-------------start predict----------------'
s = u'为 寂寞 的 夜空 画 上 一个 月亮'
print posSent(s, model, posInfo)
#posFile('~/work/corpus/icwb2/testing/msr_test.utf8', './msr_test.utf8.pos', model, posInfo)
if __name__ == '__main__':
test()
中文NLP序列标注之NER
预处理
模型
中文NLP序列标注之DP
To be continue...
PS：全贴代码有点长，等我找时间再整理一下。
