4 releases

0.1.3 Feb 2, 2022
0.1.2 Feb 1, 2022
0.1.1 Feb 1, 2022
0.1.0 Feb 1, 2022

#550 in Text processing

26 downloads per month

MIT license


Rust-based Natural Language Toolkit (rsnltk)

A Rust library to support natural language processing with pure Rust implementation and Python bindings

Rust Docs | Crates Home Page | Tests | NER-Kit


The rsnltk library integrates various existing Python-written NLP toolkits for powerful text analysis in Rust-based applications.


This toolkit is based on the Python-written Stanza and other important NLP crates.

A list of functions from Stanza and others we bind here include:

  • Tokenize
  • Sentence Segmentation
  • Multi-Word Token Expansion
  • Part-of-Speech & Morphological Features
  • Named Entity Recognition
  • Sentiment Analysis
  • Language Identification
  • Dependency Tree Analysis

Some amazing crates are also included in rsnltk but with simplified APIs for actual use:

Additionally, we can calculate the similarity between words based on WordNet though the semantic-kit PyPI project via pip install semantic-kit.


  1. Make sure you install Python 3.6.6+ and PIP environment in your computer. Type python -V in the Terminal should print no error message;

  2. Install our Python-based ner-kit (version>=0.0.5a2) for binding the Stanza package via pip install ner-kit==0.0.5a2;

  3. Then, Rust should be also installed in your computer. I use IntelliJ to develop Rust-based applications, where you can write Rust codes;

  4. Create a simple Rust application project with a main() function.

  5. Add the rsnltk dependency to the Cargo.toml file, keep up the Latest version.

  6. After you add the rsnltk dependency in the toml file, install necessary language models from Stanza using the following Rust code for the first time you use this package.

fn init_rsnltk_and_test(){
    // 1. first install the necessary language models 
    // using language codes
    let list_lang=vec!["en","zh"]; 
    //e.g. you install two language models, 
    // namely, for English and Chinese text analysis.
    // 2. then do test NLP tasks
    let text="I like Beijing!";
    let lang="en";
    // 2. Uncomment the below codes for Chinese NER
    // let text="我喜欢北京、上海和纽约!";
    // let lang="zh";
    let list_ner=ner(text,lang);
    for ner in list_ner{

Or you can manually install those language models via the Python-written ner-kit package which provides more features in using Stanza. Go to: ner-kit

If no error occurs in the above example, then it works. Finally, you can try the following advanced example usage.

Currently, we tested the use of English and Chinese language models; however, other language models should work as well.

Examples with Stanza Bindings

Example 1: Part-of-speech Analysis

    fn test_pos(){
    //let text="我喜欢北京、上海和纽约!";
    //let lang="zh";
    let text="I like apple";
    let lang="en";
    let list_result=pos(text,lang);
    for word in list_result{

Example 2: Sentiment Analysis

    fn test_sentiment(){
        //let text="I like Beijing!";
        //let lang="en";
        let text="我喜欢北京";
        let lang="zh";
        let sentiments=sentiment(text,lang);
        for sen in sentiments{

Example 3: Named Entity Recognition

    fn test_ner(){
        // 1. for English NER
        let text="I like Beijing!";
        let lang="en";
        // 2. Uncomment the below codes for Chinese NER
        // let text="我喜欢北京、上海和纽约!";
        // let lang="zh";
        let list_ner=ner(text,lang);
        for ner in list_ner{

Example 4: Tokenize for Multiple Languages

    fn test_tokenize(){
        let text="我喜欢北京、上海和纽约!";
        let lang="zh";
        let list_result=tokenize(text,lang);
        for ner in list_result{

Example 5: Tokenize Sentence

    fn test_tokenize_sentence(){
        let text="I like apple. Do you like it? No, I am not sure!";
        let lang="en";
        let list_sentences=tokenize_sentence(text,lang);
        for sentence in list_sentences{
            println!("Sentence: {}",sentence);

Example 6: Language Identification

fn test_lang(){
    let list_text = vec!["I like Beijing!",
                         "Bonjour le monde!"];
    let list_result=lang(list_text);
    for lang in list_result{

Example 7: MWT expand

    fn test_mwt_expand(){
        let text="Nous avons atteint la fin du sentier.";
        let lang="fr";
        let list_result=mwt_expand(text,lang);

Example 8: Estimate the similarity between words in WordNet

You need to firstly install semantic-kit PyPI package!

    fn test_wordnet_similarity(){
        let s1="dog.n.1";
        let s2="cat.n.2";
        let sims=wordnet_similarity(s1,s2);
        for sim in sims{

Example 9: Obtain a dependency tree from a text

fn test_dependency_tree(){
    let text="I like you. Do you like me?";
    let lang="en";
    let list_results=dependency_tree(text,lang);
    for list_token in list_results{
        for token in list_token{


Examples in Pure Rust

Example 1: Word2Vec similarity

fn test_open_wv_bin(){
    let wv_model=wv_get_model("GoogleNews-vectors-negative300.bin");
    let positive = vec!["woman", "king"];
    let negative = vec!["man"];
    println!("analogy: {:?}", wv_analogy(&wv_model,positive, negative, 10));
    println!("cosine: {:?}", wv_cosine(&wv_model,"man", 10));

Example 2: Text summarization

    use rsnltk::native::summarizer::*;
    fn test_summarize(){
        let text="Some large txt...";
        let stopwords=&[];
        let summarized_text=summarize(text,stopwords,5);

Example 3: Get token list from English strings

use rsnltk::native::token::get_token_list;
fn test_get_token_list(){
        let s="Hello, Rust. How are you?";
        let result=get_token_list(s);
        for r in result{

Example 4: Word segmentation for some language where no space exists between terms, e.g. Chinese text.

We implement three word segmentation methods in this version:

  • Forward Maximum Matching (fmm), which is baseline method
  • Backward Maximum Matching (bmm), which is considered better
  • Bidirectional Maximum Matching (bimm), high accuracy but low speed
use rsnltk::native::segmentation::*;
fn test_real_word_segmentation(){
    let dict_path="30wdict.txt"; // empty if only for tokenizing
    let stop_path="baidu_stopwords.txt";// empty when no stop words
    let _sentence="美国太空总署希望,在深海的探险发现将有助于解开一些外太空的秘密,\
    let meaningful_words=get_segmentation(_sentence,dict_path,stop_path, "bimm");
    // bimm can be changed to fmm or bmm. 
    println!("Result: {:?}",meaningful_words);


Thank Stanford NLP Group for their hard work in Stanza.


The rsnltk library with MIT License is provided by Donghua Chen.


~128K SLoC