Introduction

Installation

Limitations of the "file" protocol

Frequently asked questions

Syntax, keywords and built-in functions

Standard distribution

import implementation

Brython packages

Browser interface

Brython-specific built-in modules

Working with Brython

Cookbook

module javascript

Imports the Javascript module at specified url and adds alias to the local namespace.

If alias is missing, the module name is computed from the url; for instance, for import_js('js_test.js') the alias is js_test.

The module must define the name $module, an objet whose attributes make the namespace of the imported module.

Example: if Javascript script at js_test.js is

var $module = {
    x: 1
}

then a Python script can use it this way:

import javascript

javascript.import_js("js_test.js", alias="js_module")
assert js_module.x == 1

imports the Javascript modules whose urls are in the list refs. When they have all been imported, function callback is called with the module as arguments. callback() thus takes as many arguments as there are urls in refs.

For instance if module exporter.js is

const x = 1

export {x}

it can be used in a Python script with

import javascript

def main(module):
    assert module.x == 1

javascript.import_modules(
    ['/path/to/exporter.js'],
    main)

See in the gallery a use case with the modules of three.js.

The class of Javascript objects used in a Python program. If a Javascript program defines an object with

window.jsobj = {x: 1}

it can be tested in a Python program with

from browser import window
import javascript

assert isinstance(window.jsobj, javascript.JSObject)

Returns the Javascript code generated by Brython from the Python source code src.

Returns the Brython object matching the value of the Javascript object this. It may be useful when using Javascript frameworks, eg when a callback function uses the value of this.

Constructor of date / time objects.

from javascript import Date

date = Date.new(2012, 6, 10)
print(date.toDateString())

Object to convert to and from JSON objects. It exposes two functions:

stringify: serialize simple objects (dictionaries, lists, tuples, integers, reals, strings)

parse: conversion of a JSON-formatted string into a simple object

Object for mathematical functions and constants.

the Javascript object null. Can be used to test if a Javascript object is null.

Constructor for objects of type "number".

Constructor of "regular expression" objects, using the Javascript-specific syntax, which doesn't fully match that of Python. The method exec() of instances of this class can be applied to Python strings:

from javascript import RegExp

re = RegExp.new(r"^test(\d+)$")
print(re.exec("test44"))

Constructor of Javascript objects of type "string". Must be used to call methods that accept Javascript regular expressions as parameters:

from javascript import RegExp, String

re = RegExp.new(r"^test(\d+)$")
print(String.new("test33").search(re))

the Javascript object undefined. Can be used to test if a Javascript object is undefined.