Call Python function from JavaScript code

Question

I'd like to call a Python function from JavaScript code, because there isn't an alternative in JavaScript for doing what I want. Is this possible? Could you adjust the below snippet to work?

JavaScript code:

var tag = document.getElementsByTagName("p")[0]; text = tag.innerHTML; // Here I would like to call the Python interpreter with Python function arrOfStrings = openSomehowPythonInterpreter("~/pythoncode.py", "processParagraph(text)"); 

~/pythoncode.py contains functions using advanced libraries that don't have an easy to write equivalent in JavaScript:

import nltk # is not in JavaScript def processParagraph(text):   ...   nltk calls   ...   return lst # returns a list of strings (will be converted to JavaScript array) 

Answer 1

All you need is to make an ajax request to your pythoncode. You can do this with jquery http://api.jquery.com/jQuery.ajax/, or use just javascript

$.ajax({   type: "POST",   url: "~/pythoncode.py",   data: { param: text} }).done(function( o ) {    // do something }); 

Answer 2

From the document.getElementsByTagName I guess you are running the javascript in a browser.

The traditional way to expose functionality to javascript running in the browser is calling a remote URL using AJAX. The X in AJAX is for XML, but nowadays everybody uses JSON instead of XML.

For example, using jQuery you can do something like:

$.getJSON('http://example.com/your/webservice?param1=x&param2=y',      function(data, textStatus, jqXHR) {         alert(data);     } ) 

You will need to implement a python webservice on the server side. For simple webservices I like to use Flask.

A typical implementation looks like:

@app.route("/your/webservice") def my_webservice():     return jsonify(result=some_function(**request.args))  

You can run IronPython (kind of Python.Net) in the browser with silverlight, but I don't know if NLTK is available for IronPython.