--- mapped_pages: - https://www.elastic.co/guide/en/elasticsearch/plugins/current/analysis-nori-tokenizer.html --- # nori_tokenizer [analysis-nori-tokenizer] The `nori_tokenizer` accepts the following settings: `decompound_mode` : The decompound mode determines how the tokenizer handles compound tokens. It can be set to: `none` : No decomposition for compounds. Example output: ``` 가거도항 가곡역 ``` `discard` : Decomposes compounds and discards the original form (**default**). Example output: ``` 가곡역 => 가곡, 역 ``` `mixed` : Decomposes compounds and keeps the original form. Example output: ``` 가곡역 => 가곡역, 가곡, 역 ``` `discard_punctuation` : Whether punctuation should be discarded from the output. Defaults to `true`. `lenient` : Whether the `user_dictionary` should be deduplicated on the provided `text`. False by default causing duplicates to generate an error. `user_dictionary` : The Nori tokenizer uses the [mecab-ko-dic dictionary](https://bitbucket.org/eunjeon/mecab-ko-dic) by default. A `user_dictionary` with custom nouns (`NNG`) may be appended to the default dictionary. The dictionary should have the following format: ```txt [ ... ] ``` The first token is mandatory and represents the custom noun that should be added in the dictionary. For compound nouns the custom segmentation can be provided after the first token (`[ ... ]`). The segmentation of the custom compound nouns is controlled by the `decompound_mode` setting. As a demonstration of how the user dictionary can be used, save the following dictionary to `$ES_HOME/config/userdict_ko.txt`: ```txt c++ <1> C쁠쁠 세종 세종시 세종 시 <2> ``` 1. A simple noun 2. A compound noun (`세종시`) followed by its decomposition: `세종` and `시`. Then create an analyzer as follows: ```console PUT nori_sample { "settings": { "index": { "analysis": { "tokenizer": { "nori_user_dict": { "type": "nori_tokenizer", "decompound_mode": "mixed", "discard_punctuation": "false", "user_dictionary": "userdict_ko.txt", "lenient": "true" } }, "analyzer": { "my_analyzer": { "type": "custom", "tokenizer": "nori_user_dict" } } } } } } GET nori_sample/_analyze { "analyzer": "my_analyzer", "text": "세종시" <1> } ``` 1. Sejong city The above `analyze` request returns the following: ```console-result { "tokens" : [ { "token" : "세종시", "start_offset" : 0, "end_offset" : 3, "type" : "word", "position" : 0, "positionLength" : 2 <1> }, { "token" : "세종", "start_offset" : 0, "end_offset" : 2, "type" : "word", "position" : 0 }, { "token" : "시", "start_offset" : 2, "end_offset" : 3, "type" : "word", "position" : 1 }] } ``` 1. This is a compound token that spans two positions (`mixed` mode). `user_dictionary_rules` : You can also inline the rules directly in the tokenizer definition using the `user_dictionary_rules` option: ```console PUT nori_sample { "settings": { "index": { "analysis": { "tokenizer": { "nori_user_dict": { "type": "nori_tokenizer", "decompound_mode": "mixed", "user_dictionary_rules": ["c++", "C쁠쁠", "세종", "세종시 세종 시"] } }, "analyzer": { "my_analyzer": { "type": "custom", "tokenizer": "nori_user_dict" } } } } } } ``` The `nori_tokenizer` sets a number of additional attributes per token that are used by token filters to modify the stream. You can view all these additional attributes with the following request: ```console GET _analyze { "tokenizer": "nori_tokenizer", "text": "뿌리가 깊은 나무는", <1> "attributes" : ["posType", "leftPOS", "rightPOS", "morphemes", "reading"], "explain": true } ``` 1. A tree with deep roots Which responds with: ```console-result { "detail": { "custom_analyzer": true, "charfilters": [], "tokenizer": { "name": "nori_tokenizer", "tokens": [ { "token": "뿌리", "start_offset": 0, "end_offset": 2, "type": "word", "position": 0, "leftPOS": "NNG(General Noun)", "morphemes": null, "posType": "MORPHEME", "reading": null, "rightPOS": "NNG(General Noun)" }, { "token": "가", "start_offset": 2, "end_offset": 3, "type": "word", "position": 1, "leftPOS": "JKS(Subject case marker)", "morphemes": null, "posType": "MORPHEME", "reading": null, "rightPOS": "JKS(Subject case marker)" }, { "token": "깊", "start_offset": 4, "end_offset": 5, "type": "word", "position": 2, "leftPOS": "VA(Adjective)", "morphemes": null, "posType": "MORPHEME", "reading": null, "rightPOS": "VA(Adjective)" }, { "token": "은", "start_offset": 5, "end_offset": 6, "type": "word", "position": 3, "leftPOS": "ETM(Adnominal form transformative ending)", "morphemes": null, "posType": "MORPHEME", "reading": null, "rightPOS": "ETM(Adnominal form transformative ending)" }, { "token": "나무", "start_offset": 7, "end_offset": 9, "type": "word", "position": 4, "leftPOS": "NNG(General Noun)", "morphemes": null, "posType": "MORPHEME", "reading": null, "rightPOS": "NNG(General Noun)" }, { "token": "는", "start_offset": 9, "end_offset": 10, "type": "word", "position": 5, "leftPOS": "JX(Auxiliary postpositional particle)", "morphemes": null, "posType": "MORPHEME", "reading": null, "rightPOS": "JX(Auxiliary postpositional particle)" } ] }, "tokenfilters": [] } } ```