diff --git a/README.md b/README.md index 3eef6d0..bd464b3 100644 --- a/README.md +++ b/README.md @@ -1,6 +1,186 @@ jieba ======== +"结巴"中文分词:做最好的Python中文分词组件jieba +======== "结巴"中文分词:做最好的Python中文分词组件 +"Jieba" (Chinese for "to stutter") Chinese text segmentation: built to be the best Python Chinese word segmentation module. +- _Scroll down for English documentation._ + +Feature +======== +* 支持两种分词模式: +* 1)默认模式,试图将句子最精确地切开,适合文本分析; +* 2)全模式,把句子中所有的可以成词的词语都扫描出来,适合搜索引擎。 + +Usage +======== +* 全自动安装:`easy_install jieba` 或者 `pip install jieba` +* 半自动安装:先下载http://pypi.python.org/pypi/jieba/ ,解压后运行python setup.py install +* 手动安装:将jieba目录放置于当前目录或者site-packages目录 +* 通过import jieba 来引用 (第一次import时需要构建Trie树,需要几秒时间) + +Algorithm +======== +* 基于Trie树结构实现高效的词图扫描,生成句子中汉字构成的有向无环图(DAG) +* 采用了记忆化搜索实现最大概率路径的计算, 找出基于词频的最大切分组合 +* 对于未登录词,采用了基于汉字位置概率的模型,使用了Viterbi算法 + +功能 1):分词 +========== +* jieba.cut方法接受两个输入参数: 1) 第一个参数为需要分词的字符串 2)cut_all参数用来控制分词模式 +* 待分词的字符串可以是gbk字符串、utf-8字符串或者unicode +* jieba.cut返回的结构是一个可迭代的generator,可以使用for循环来获得分词后得到的每一个词语(unicode),也可以用list(jieba.cut(...))转化为list + +代码示例( 分词 ) + + #encoding=utf-8 + import jieba + + seg_list = jieba.cut("我来到北京清华大学",cut_all=True) + print "Full Mode:", "/ ".join(seg_list) #全模式 + + seg_list = jieba.cut("我来到北京清华大学",cut_all=False) + print "Default Mode:", "/ ".join(seg_list) #默认模式 + + seg_list = jieba.cut("他来到了网易杭研大厦") + print ", ".join(seg_list) + +Output: + + Full Mode: 我/ 来/ 来到/ 到/ 北/ 北京/ 京/ 清/ 清华/ 清华大学/ 华/ 华大/ 大/ 大学/ 学 + + Default Mode: 我/ 来到/ 北京/ 清华大学 + + 他, 来到, 了, 网易, 杭研, 大厦 (此处,“杭研”并没有在词典中,但是也被Viterbi算法识别出来了) + +功能 2) :添加自定义词典 +================ + +* 开发者可以指定自己自定义的词典,以便包含jieba词库里没有的词。虽然jieba有新词识别能力,但是自行添加新词可以保证更高的正确率 +* 用法: jieba.load_userdict(file_name) # file_name为自定义词典的路径 +* 词典格式和dict.txt一样,一个词占一行;每一行分为两部分,一部分为词语,另一部分为词频,用空格隔开 +* 范例: + + 云计算 5 + 李小福 2 + 创新办 3 + + 之前: 李小福 / 是 / 创新 / 办 / 主任 / 也 / 是 / 云 / 计算 / 方面 / 的 / 专家 / + + 加载自定义词库后: 李小福 / 是 / 创新办 / 主任 / 也 / 是 / 云计算 / 方面 / 的 / 专家 / + + +功能 3) :关键词提取 +================ +* jieba.analyse.extract_tags(sentence,topK) #需要先import jieba.analyse +* setence为待提取的文本 +* topK为返回几个TF/IDF权重最大的关键词,默认值为20 + +代码示例 (关键词提取) + + https://github.com/fxsjy/jieba/blob/master/test/extract_tags.py + + +分词速度 +========= +* 1.5 MB / Second in Full Mode +* 400 KB / Second in Default Mode +* Test Env: Intel(R) Core(TM) i7-2600 CPU @ 3.4GHz;《围城》.txt + +在线演示 +========= +http://209.222.69.242:9000/ + + +jieba +======== +"Jieba" (Chinese for "to stutter") Chinese text segmentation: built to be the best Python Chinese word segmentation module. + +Features +======== +* Support two types of segmentation mode: +* 1) Default mode, attempt to cut the sentence into the most accurate segmentation, which is suitable for text analysis; +* 2) Full mode, break the words of the sentence into words scanned, which is suitable for search engines. + +Usage +======== +* Fully automatic installation: `easy_install jieba` or `pip install jieba` +* Semi-automatic installation: Download http://pypi.python.org/pypi/jieba/ , after extracting run `python setup.py install` +* Manutal installation: place the `jieba` directory in the current directory or python site-packages directory. +* Use `import jieba` to import, which will first build the Trie tree only on first import (takes a few seconds). + +Algorithm +======== +* Based on the Trie tree structure to achieve efficient word graph scanning; sentences using Chinese characters constitute a directed acyclic graph (DAG) +* Employs memory search to calculate the maximum probability path, in order to identify the maximum tangential points based on word frequency combination +* For unknown words, the character position probability-based model is used, using the Viterbi algorithm + +Function 1): cut +========== +* The `jieba.cut` method accepts to input parameters: 1) the first parameter is the string that requires segmentation, and the 2) second parameter is `cut_all`, a parameter used to control the segmentation pattern. +* `jieba.cut` returned structure is an iterative generator, where you can use a `for` loop to get the word segmentation (in unicode), or `list(jieba.cut( ... ))` to create a list. + +Code example: segmentation +========== + + #encoding=utf-8 + import jieba + + seg_list = jieba.cut("我来到北京清华大学",cut_all=True) + print "Full Mode:", "/ ".join(seg_list) #全模式 + + seg_list = jieba.cut("我来到北京清华大学",cut_all=False) + print "Default Mode:", "/ ".join(seg_list) #默认模式 + + seg_list = jieba.cut("他来到了网易杭研大厦") + print ", ".join(seg_list) + + +Output: + + Full Mode: 我/ 来/ 来到/ 到/ 北/ 北京/ 京/ 清/ 清华/ 清华大学/ 华/ 华大/ 大/ 大学/ 学 + + Default Mode: 我/ 来到/ 北京/ 清华大学 + + 他, 来到, 了, 网易, 杭研, 大厦 (In this case, "杭研" is not in the dictionary, but is identified by the Viterbi algorithm) + +Function 2): Add a custom dictionary +========== + +* Developers can specify their own custom dictionary to include in the jieba thesaurus. jieba has the ability to identify new words, but adding your own new words can ensure a higher rate of correct segmentation. +* Usage: `jieba.load_userdict(file_name) # file_name is a custom dictionary path` +* The dictionary format is the same as that of `dict.txt`: one word per line; each line is divided into two parts, the first is the word itself, the other is the word frequency, separated by a space +* Example: + + 云计算 5 + 李小福 2 + 创新办 3 + + 之前: 李小福 / 是 / 创新 / 办 / 主任 / 也 / 是 / 云 / 计算 / 方面 / 的 / 专家 / + + 加载自定义词库后: 李小福 / 是 / 创新办 / 主任 / 也 / 是 / 云计算 / 方面 / 的 / 专家 / + +Function 3): Keyword Extraction +================ +* `jieba.analyse.extract_tags(sentence,topK) # needs to first import jieba.analyse` +* `setence`: the text to be extracted +* `topK`: To return several TF / IDF weights for the biggest keywords, the default value is 20 + +Code sample (keyword extraction) + + https://github.com/fxsjy/jieba/blob/master/test/extract_tags.py + + +Segmentation speed +========= +* 1.5 MB / Second in Full Mode +* 400 KB / Second in Default Mode +* Test Env: Intel(R) Core(TM) i7-2600 CPU @ 3.4GHz;《围城》.txt + +Online demo +========= +http://209.222.69.242:9000/ + Feature ========