Conversion from JavaScript to Python code?

Question

Is there a relatively quick program out there to accomplish at least the basics of this? Just a few regexes? I'm willing to do some manual conversion, but this is a pretty big set of scripts.

Answer 1

You can translate JavaScript to Python using Js2Py. It supports whole JavaScript and you can use it to translate large JavaScript modules like esprima.js (a JavaScript 6 parser).

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Short demo:

>>> import js2py
>>> f = js2py.eval_js( "function $(a) {return a + arguments[1]}" )
>>> f
function $(a) { [python code] }
>>> f(1, 2, 3)
3

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This is how the translated function looks like internally (it's rather ugly):

>>> print js2py.translate_js( "function $(a) {return a + arguments[1]}" )
from js2py.pyjs import *
var = Scope( JS_BUILTINS )
set_global_object(var)
# Code follows:
var.registers([u'$'])
@Js
def PyJsHoistedNonPyName(a, this, arguments, var=var):
    var = Scope({u'a':a, u'this':this, u'arguments':arguments}, var)
    var.registers([u'a'])
    return (var.get(u'a')+var.get(u'arguments').get(u'1'))
PyJsHoistedNonPyName.func_name = u'$'
var.put(u'$', PyJsHoistedNonPyName)

Answer 2

Updated

Now several (4) years later this (almost certainly) can be done; though certainly not with RegEx. I suggest future readers look to @Piotr Dabkowski's answer.. Or some of the other answers. (I don't know having not tried them)

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Original Answer

Hm this is a hard one. The definition of a compiler is translates from a higher level language to a lower level language. eg python to machine-code. or java to javascript (google has a rather famous compiler for this somewhere - its' what makes google doc easier to make) Python to javascript compilers abound. technically javascript to python would be a decompiler. (afaik)

I found some speculation about a javascript-python converter here: follow the tread through. it mostly speaks of how it wouldn't be too hard to do. I can't find anything , but that doesn't mean it's no out there.

Regex is not suitable, regex is suitable only for regular languages. programming languages are not normally regular languages. see this

Answer 3

This answer might be about 2 years late but how about js -> CoffeeScript -> python? If you use something like http://js2.coffee/ to convert to cs, then things like indentation and lists are already done for you.

Answer 4

If what you are asking is converting a few regexs in javascript to Python equivalent, the basics of regular expressions are mostly pretty standard. check out the Python re module doc. See if what you are using is documented. Also of interest to you is this page.

If you are talking about converting javascript code to Python equivalent, the best converter is you. Learn about Python, and then convert them manually. there is nothing else better than the human being. Programming constructs like loops, variables, arrays are pretty common and standard you will recognize instantly how to use them straight away.