用几十行代码实现python中英文分词

说到分词大家肯定一般认为是很高深的技术,但是今天作者用短短几十行代码就搞定了,感叹python很强大啊!作者也很强大。不过这个只是正向最大匹配,没有机器学习能力

注意:使用前先要下载搜狗词库

# -*- coding:utf-8 -*-
#写了一个简单的支持中文的正向最大匹配的机械分词,其它不用解释了,就几十行代码
#附:搜狗词库下载地址:http://vdisk.weibo.com/s/7rle5
import string
__dict = {}
def load_dict(dict_file=’words.dic’):
#加载词库,把词库加载成一个key为首字符,value为相关词的列表的字典
words = [unicode(line, ‘utf-8’).split() for line in open(dict_file)]
for word_len, word in words:
first_char = word[0]
__dict.setdefault(first_char, [])
__dict[first_char].append(word)
#按词的长度倒序排列
for first_char, words in __dict.items():
__dict[first_char] = sorted(words, key=lambda x:len(x), reverse=true)
def __match_ascii(i, input):
#返回连续的英文字母,数字,符号
result = ”
for i in range(i, len(input)):
if not input[i] in string.ascii_letters: break
result += input[i]
return result
def __match_word(first_char, i , input):
#根据当前位置进行分词,ascii的直接读取连续字符,中文的读取词库
if not __dict.has_key(first_char):
if first_char in string.ascii_letters:
return __match_ascii(i, input)
return first_char
words = __dict[first_char]
for word in words:
if input[i:i+len(word)] == word:
return word
return first_char
def tokenize(input):
#对input进行分词,input必须是uncode编码
if not input: return []
tokens = []
i = 0
while i < len(input): first_char = input[i] matched_word = __match_word(first_char, i, input) tokens.append(matched_word) i += len(matched_word) return tokens if __name__ == '__main__': def get_test_text(): import urllib2 url = "http://news.baidu.com/n?cmd=4& text = urllib2.urlopen(url).read() return unicode(text, 'gbk') def load_dict_test(): load_dict() for first_char, words in __dict.items(): print '%s:%s' % (first_char, ' '.join(words)) def tokenize_test(text): load_dict() tokens = tokenize(text) for token in tokens: print token tokenize_test(unicode(u'美丽的花园里有各种各样的小动物')) tokenize_test(get_test_text())

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