摘要: 随着深度学习的快速发展，人们创建了一整套神经网络结构来解决各种各样的任务和问题。在英文分类基础上，中文文本分类的处理也同样重要...
人工智能学习离不开实践的验证，推荐大家可以多在FlyAI-AI竞赛服务平台多参加训练和竞赛，以此来提升自己的能力。FlyAI是为AI开发者提供数据竞赛并支持GPU离线训练的一站式服务平台。每周免费提供项目开源算法样例，支持算法能力变现以及快速的迭代算法模型。
目录
概述数据集合代码结果展示
一、概述
在英文分类的基础上，再看看中文分类的，是一种10分类问题（体育，科技，游戏，财经，房产，家居等）的处理。
二、数据集合
数据集为新闻，总共有四个数据文件，在/data/cnews目录下，包括内容如下图所示测试集，训练集和验证集，和单词表(最后的单词表cnews.vocab.txt可以不要，因为训练可以自动产生)。数据格式：前面为类别，后面为描述内容。
训练数据地址：链接： https://pan.baidu.com/s/1ZHh98RrjQpG5Tm-yq73vBQ 提取码：2r04
其中训练集的格式：
vocab.txt的格式：每个字一行，其中前面加上PAD。
三、代码
3.1 数据采集cnews_loader.py
# coding: utf-8
import sys
from collections import Counter
import numpy as np
import tensorflow.contrib.keras as kr
if sys.version_info[0] > 2:
is_py3 = True
else:
reload(sys)
sys.setdefaultencoding("utf-8")
is_py3 = False
def native_word(word, encoding='utf-8'):
"""如果在python2下面使用python3训练的模型，可考虑调用此函数转化一下字符编码"""
if not is_py3:
return word.encode(encoding)
else:
return word
def native_content(content):
if not is_py3:
return content.decode('utf-8')
else:
return content
def open_file(filename, mode='r'):
"""
常用文件操作，可在python2和python3间切换.
mode: 'r' or 'w' for read or write
"""
if is_py3:
return open(filename, mode, encoding='utf-8', errors='ignore')
else:
return open(filename, mode)
def read_file(filename):
"""读取文件数据"""
contents, labels = [], []
with open_file(filename) as f:
for line in f:
try:
label, content = line.strip().split('\t')
if content:
contents.append(list(native_content(content)))
labels.append(native_content(label))
except:
pass
return contents, labels
def build_vocab(train_dir, vocab_dir, vocab_size=5000):
"""根据训练集构建词汇表，存储"""
data_train, _ = read_file(train_dir)
all_data = []
for content in data_train:
all_data.extend(content)
counter = Counter(all_data)
count_pairs = counter.most_common(vocab_size - 1)
words, _ = list(zip(*count_pairs))
# 添加一个 <PAD> 来将所有文本pad为同一长度
words = ['<PAD>'] + list(words)
open_file(vocab_dir, mode='w').write('\n'.join(words) + '\n')
def read_vocab(vocab_dir):
"""读取词汇表"""
# words = open_file(vocab_dir).read().strip().split('\n')
with open_file(vocab_dir) as fp:
# 如果是py2 则每个值都转化为unicode
words = [native_content(_.strip()) for _ in fp.readlines()]
word_to_id = dict(zip(words, range(len(words))))
return words, word_to_id
def read_category():
"""读取分类目录，固定"""
categories = ['体育', '财经', '房产', '家居', '教育', '科技', '时尚', '时政', '游戏', '娱乐']
categories = [native_content(x) for x in categories]
cat_to_id = dict(zip(categories, range(len(categories))))
return categories, cat_to_id
def to_words(content, words):
"""将id表示的内容转换为文字"""
return ''.join(words[x] for x in content)
def process_file(filename, word_to_id, cat_to_id, max_length=600):
"""将文件转换为id表示"""
contents, labels = read_file(filename)
data_id, label_id = [], []
for i in range(len(contents)):
data_id.append([word_to_id[x] for x in contents[i] if x in word_to_id])
label_id.append(cat_to_id[labels[i]])
# 使用keras提供的pad_sequences来将文本pad为固定长度
x_pad = kr.preprocessing.sequence.pad_sequences(data_id, max_length)
y_pad = kr.utils.to_categorical(label_id, num_classes=len(cat_to_id)) # 将标签转换为one-hot表示
return x_pad, y_pad
def batch_iter(x, y, batch_size=64):
"""生成批次数据"""
data_len = len(x)
num_batch = int((data_len - 1) / batch_size) + 1
indices = np.random.permutation(np.arange(data_len))
x_shuffle = x[indices]
y_shuffle = y[indices]
for i in range(num_batch):
start_id = i * batch_size
end_id = min((i + 1) * batch_size, data_len)
yield x_shuffle[start_id:end_id], y_shuffle[start_id:end_id
3.2 模型搭建cnn_model.py
#!/usr/bin/python
# -*- coding: utf-8 -*-
import tensorflow as tf
class TRNNConfig(object):
"""RNN配置参数"""
# 模型参数
embedding_dim = 64 # 词向量维度
seq_length = 600 # 序列长度
num_classes = 10 # 类别数
vocab_size = 5000 # 词汇表达小
num_layers= 2 # 隐藏层层数
hidden_dim = 128 # 隐藏层神经元
rnn = 'gru' # lstm 或 gru
dropout_keep_prob = 0.8 # dropout保留比例
learning_rate = 1e-3 # 学习率
batch_size = 128 # 每批训练大小
num_epochs = 10 # 总迭代轮次
print_per_batch = 100 # 每多少轮输出一次结果
save_per_batch = 10 # 每多少轮存入tensorboard
class TextRNN(object):
"""文本分类，RNN模型"""
def __init__(self, config):
self.config = config
# 三个待输入的数据
self.input_x = tf.placeholder(tf.int32, [None, self.config.seq_length], name='input_x')
self.input_y = tf.placeholder(tf.float32, [None, self.config.num_classes], name='input_y')
self.keep_prob = tf.placeholder(tf.float32, name='keep_prob')
self.rnn()
def rnn(self):
"""rnn模型"""
def lstm_cell(): # lstm核
return tf.contrib.rnn.BasicLSTMCell(self.config.hidden_dim, state_is_tuple=True)
def gru_cell(): # gru核
return tf.contrib.rnn.GRUCell(self.config.hidden_dim)
def dropout(): # 为每一个rnn核后面加一个dropout层
if (self.config.rnn == 'lstm'):
cell = lstm_cell()
else:
cell = gru_cell()
return tf.contrib.rnn.DropoutWrapper(cell, output_keep_prob=self.keep_prob)
# 词向量映射
with tf.device('/cpu:0'):
embedding = tf.get_variable('embedding', [self.config.vocab_size, self.config.embedding_dim])
embedding_inputs = tf.nn.embedding_lookup(embedding, self.input_x)
with tf.name_scope("rnn"):
# 多层rnn网络
cells = [dropout() for _ in range(self.config.num_layers)]
rnn_cell = tf.contrib.rnn.MultiRNNCell(cells, state_is_tuple=True)
_outputs, _ = tf.nn.dynamic_rnn(cell=rnn_cell, inputs=embedding_inputs, dtype=tf.float32)
last = _outputs[:, -1, :] # 取最后一个时序输出作为结果
with tf.name_scope("score"):
# 全连接层，后面接dropout以及relu激活
fc = tf.layers.dense(last, self.config.hidden_dim, name='fc1')
fc = tf.contrib.layers.dropout(fc, self.keep_prob)
fc = tf.nn.relu(fc)
# 分类器
self.logits = tf.layers.dense(fc, self.config.num_classes, name='fc2')
self.y_pred_cls = tf.argmax(tf.nn.softmax(self.logits), 1) # 预测类别
with tf.name_scope("optimize"):
# 损失函数，交叉熵
cross_entropy = tf.nn.softmax_cross_entropy_with_logits(logits=self.logits, labels=self.input_y)
self.loss = tf.reduce_mean(cross_entropy)
# 优化器
self.optim = tf.train.AdamOptimizer(learning_rate=self.config.learning_rate).minimize(self.loss)
with tf.name_scope("accuracy"):
# 准确率
correct_pred = tf.equal(tf.argmax(self.input_y, 1), self.y_pred_cls)
self.acc = tf.reduce_mean(tf.cast(correct_pred, tf.float32))
3.3 运行代码run_cnn.py
# coding: utf-8
from __future__ import print_function
import os
import sys
import time
from datetime import timedelta
import numpy as np
import tensorflow as tf
from sklearn import metrics
from rnn_model import TRNNConfig, TextRNN
from cnews_loader import read_vocab, read_category, batch_iter, process_file, build_vocab
base_dir = '../data/cnews'
train_dir = os.path.join(base_dir, 'cnews.train.txt')
test_dir = os.path.join(base_dir, 'cnews.test.txt')
val_dir = os.path.join(base_dir, 'cnews.val.txt')
vocab_dir = os.path.join(base_dir, 'cnews.vocab.txt')
save_dir = '../checkpoints/textrnn'
save_path = os.path.join(save_dir, 'best_validation') # 最佳验证结果保存路径
def get_time_dif(start_time):
"""获取已使用时间"""
end_time = time.time()
time_dif = end_time - start_time
return timedelta(seconds=int(round(time_dif)))
def feed_data(x_batch, y_batch, keep_prob):
feed_dict = {
model.input_x: x_batch,
model.input_y: y_batch,
model.keep_prob: keep_prob
}
return feed_dict
def evaluate(sess, x_, y_):
"""评估在某一数据上的准确率和损失"""
data_len = len(x_)
batch_eval = batch_iter(x_, y_, 128)
total_loss = 0.0
total_acc = 0.0
for x_batch, y_batch in batch_eval:
batch_len = len(x_batch)
feed_dict = feed_data(x_batch, y_batch, 1.0)
y_pred_class,loss, acc = sess.run([model.y_pred_cls,model.loss, model.acc], feed_dict=feed_dict)
total_loss += loss * batch_len
total_acc += acc * batch_len
return y_pred_class,total_loss / data_len, total_acc / data_len
def train():
print("Configuring TensorBoard and Saver...")
# 配置 Tensorboard，重新训练时，请将tensorboard文件夹删除，不然图会覆盖
tensorboard_dir = '../tensorboard/textrnn'
if not os.path.exists(tensorboard_dir):
os.makedirs(tensorboard_dir)
tf.summary.scalar("loss", model.loss)
tf.summary.scalar("accuracy", model.acc)
merged_summary = tf.summary.merge_all()
writer = tf.summary.FileWriter(tensorboard_dir)
# 配置 Saver
saver = tf.train.Saver()
if not os.path.exists(save_dir):
os.makedirs(save_dir)
print("Loading training and validation data...")
# 载入训练集与验证集
start_time = time.time()
x_train, y_train = process_file(train_dir, word_to_id, cat_to_id, config.seq_length)
x_val, y_val = process_file(val_dir, word_to_id, cat_to_id, config.seq_length)
time_dif = get_time_dif(start_time)
print("Time usage:", time_dif)
# 创建session
session = tf.Session()
session.run(tf.global_variables_initializer())
writer.add_graph(session.graph)
print('Training and evaluating...')
start_time = time.time()
total_batch = 0 # 总批次
best_acc_val = 0.0 # 最佳验证集准确率
last_improved = 0 # 记录上一次提升批次
require_improvement = 1000 # 如果超过1000轮未提升，提前结束训练
flag = False
for epoch in range(config.num_epochs):
print('Epoch:', epoch + 1)
batch_train = batch_iter(x_train, y_train, config.batch_size)
for x_batch, y_batch in batch_train:
feed_dict = feed_data(x_batch, y_batch, config.dropout_keep_prob)
if total_batch % config.save_per_batch == 0:
# 每多少轮次将训练结果写入tensorboard scalar
s = session.run(merged_summary, feed_dict=feed_dict)
writer.add_summary(s, total_batch)
if total_batch % config.print_per_batch == 0:
# 每多少轮次输出在训练集和验证集上的性能
feed_dict[model.keep_prob] = 1.0
loss_train, acc_train = session.run([model.loss, model.acc], feed_dict=feed_dict)
y_pred_class,loss_val, acc_val = evaluate(session, x_val, y_val) # todo
if acc_val > best_acc_val:
# 保存最好结果
best_acc_val = acc_val
last_improved = total_batch
saver.save(sess=session, save_path=save_path)
improved_str = '*'
else:
improved_str = ''
time_dif = get_time_dif(start_time)
msg = 'Iter: {0:>6}, Train Loss: {1:>6.2}, Train Acc: {2:>7.2%},' \
+ ' Val Loss: {3:>6.2}, Val Acc: {4:>7.2%}, Time: {5} {6}'
print(msg.format(total_batch, loss_train, acc_train, loss_val, acc_val, time_dif, improved_str))
session.run(model.optim, feed_dict=feed_dict) # 运行优化
total_batch += 1
if total_batch - last_improved > require_improvement:
# 验证集正确率长期不提升，提前结束训练
print("No optimization for a long time, auto-stopping...")
flag = True
break # 跳出循环
if flag: # 同上
break
def test():
print("Loading test data...")
start_time = time.time()
x_test, y_test = process_file(test_dir, word_to_id, cat_to_id, config.seq_length)
session = tf.Session()
session.run(tf.global_variables_initializer())
saver = tf.train.Saver()
saver.restore(sess=session, save_path=save_path) # 读取保存的模型
print('Testing...')
y_pred,loss_test, acc_test = evaluate(session, x_test, y_test)
msg = 'Test Loss: {0:>6.2}, Test Acc: {1:>7.2%}'
print(msg.format(loss_test, acc_test))
batch_size = 128
data_len = len(x_test)
num_batch = int((data_len - 1) / batch_size) + 1
y_test_cls = np.argmax(y_test, 1)
y_pred_cls = np.zeros(shape=len(x_test), dtype=np.int32) # 保存预测结果
for i in range(num_batch): # 逐批次处理
start_id = i * batch_size
end_id = min((i + 1) * batch_size, data_len)
feed_dict = {
model.input_x: x_test[start_id:end_id],
model.keep_prob: 1.0
}
y_pred_cls[start_id:end_id] = session.run(model.y_pred_cls, feed_dict=feed_dict)
# 评估
print("Precision, Recall and F1-Score...")
print(metrics.classification_report(y_test_cls, y_pred_cls, target_names=categories))
# 混淆矩阵
print("Confusion Matrix...")
cm = metrics.confusion_matrix(y_test_cls, y_pred_cls)
print(cm)
time_dif = get_time_dif(start_time)
print("Time usage:", time_dif)
if __name__ == '__main__':
print('Configuring RNN model...')
config = TRNNConfig()
if not os.path.exists(vocab_dir): # 如果不存在词汇表，重建
build_vocab(train_dir, vocab_dir, config.vocab_size)
categories, cat_to_id = read_category()
words, word_to_id = read_vocab(vocab_dir)
config.vocab_size = len(words)
model = TextRNN(config)
option='train'
if option == 'train':
train()
else:
test()
3.4 预测predict.py
# coding: utf-8
from __future__ import print_function
import os
import tensorflow as tf
import tensorflow.contrib.keras as kr
from rnn_model import TRNNConfig, TextRNN
from cnews_loader import read_category, read_vocab
try:
bool(type(unicode))
except NameError:
unicode = str
base_dir = '../data/cnews'
vocab_dir = os.path.join(base_dir, 'cnews.vocab.txt')
save_dir = '../checkpoints/textrnn'
save_path = os.path.join(save_dir, 'best_validation') # 最佳验证结果保存路径
class RnnModel:
def __init__(self):
self.config = TRNNConfig()
self.categories, self.cat_to_id = read_category()
self.words, self.word_to_id = read_vocab(vocab_dir)
self.config.vocab_size = len(self.words)
self.model = TextRNN(self.config)
self.session = tf.Session()
self.session.run(tf.global_variables_initializer())
saver = tf.train.Saver()
saver.restore(sess=self.session, save_path=save_path) # 读取保存的模型
def predict(self, message):
# 支持不论在python2还是python3下训练的模型都可以在2或者3的环境下运行
content = unicode(message)
data = [self.word_to_id[x] for x in content if x in self.word_to_id]
feed_dict = {
self.model.input_x: kr.preprocessing.sequence.pad_sequences([data], self.config.seq_length),
self.model.keep_prob: 1.0
}
y_pred_cls = self.session.run(self.model.y_pred_cls, feed_dict=feed_dict)
return self.categories[y_pred_cls[0]]
if __name__ == '__main__':
rnn_model = RnnModel()
test_demo = ['三星ST550以全新的拍摄方式超越了以往任何一款数码相机',
'热火vs骑士前瞻：皇帝回乡二番战 东部次席唾手可得新浪体育讯北京时间3月30日7:00']
for i in test_demo:
print(rnn_model.predict(i))
四、结果展示
训练时长，接近2小时
相关代码可见：https://github.com/yifanhunter/textClassifier_chinese
有关于‘文本分类’的竞赛项目，大家可移步官网进行查看和参赛！
更多精彩内容请访问FlyAI-AI竞赛服务平台；为AI开发者提供数据竞赛并支持GPU离线训练的一站式服务平台；每周免费提供项目开源算法样例，支持算法能力变现以及快速的迭代算法模型。
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