esprima

Esprima (esprima.org_, BSD license) is a high performance, standard-compliant ECMAScript_ parser officially written in ECMAScript (also popularly known as JavaScript_) and ported to Python. Esprima is created and maintained by Ariya Hidayat_, with the help of many contributors_.

Python port is a line-by-line manual translation and was created and is maintained by German Mendez Bravo (Kronuz)_.

Features

• Full support for ECMAScript 2017 (`ECMA-262 8th

Edition <http://www.ecma-international.org/publications/standards/Ecma-262.htm>`__)

• Sensible `syntax tree

format <https://github.com/estree/estree/blob/master/es5.md>__ as standardized by ESTree project <https://github.com/estree/estree>`__

• Experimental support for JSX_, a

syntax extension for React_

• Optional tracking of syntax node location (index-based and

line-column)

• Heavily tested_ (~1500 `unit

tests <https://github.com/jquery/esprima/tree/master/test/fixtures>__ with full code coverage <https://codecov.io/github/jquery/esprima>`__)

Installation

pip install esprima

API

Esprima can be used to perform lexical analysis_ (tokenization) or syntactic analysis_ (parsing) of a JavaScript program.

A simple example:

>>> import esprima
>>> program = 'const answer = 42'

>>> esprima.tokenize(program)
[{
    type: "Keyword",
    value: "const"
}, {
    type: "Identifier",
    value: "answer"
}, {
    type: "Punctuator",
    value: "="
}, {
    type: "Numeric",
    value: "42"
}]

>>> esprima.parseScript(program)
{
    body: [
        {
            kind: "const",
            declarations: [
                {
                    init: {
                        raw: "42",
                        type: "Literal",
                        value: 42
                    },
                    type: "VariableDeclarator",
                    id: {
                        type: "Identifier",
                        name: "answer"
                    }
                }
            ],
            type: "VariableDeclaration"
        }
    ],
    type: "Program",
    sourceType: "script"
}

For more information, please read the complete documentation_.