json-five 0.1.0

A JSON5 parser that, among other features, supports round-trip preservation of comments

# json-five

JSON5 for Python

[](https://json-five.readthedocs.io/en/latest/?badge=latest) [](https://travis-ci.com/spyoungtech/json-five) [](https://pypi.org/project/json-five/) [](https://pypi.org/project/json-five/) [](https://coveralls.io/github/spyoungtech/json-five?branch=master)

## Installation

` pip install json-five `

This project has just one requirement: the [sly](https://github.com/dabeaz/sly) package.

## Usage

NOTE: the import name is different from the install name (sorry, many were taken already)

`python >>> import json5 >>> json_text = """{ // This is a JSON5 comment "foo": "bar" /* this is a JSON5 block comment that can span lines /* "bacon": "eggs" } """ >>> json5.loads(json_text) {"foo": "bar", "bacon": "eggs"} `

## Project goals

• support a similar interface to the json module with support for JSON5 sources

• support round-trip preservation of comments

## Status/milestones

This project is in very early stages of development. The following are some milestones that hopefully will be able to be marked as done as development progresses.

• [x] parse json5 to Python (ignoring comments) - [x] line comments - [x] block comments - [x] numeric literals - [x] trailing commas for arrays and objects - [x] line continuations - [x] ecma identifiers as object keys - [x] leading plus for numbers - [x] single quoted strings - [x] escape characters in strings

• [x] dump python to JSON (no comment support) - [x] indent style (that matches json) - [ ] style options (quotes, trailing commas, etc) - [ ] helper classes for dumping types as other literals (hexadecimal numbers, identifiers, etc) - [x] load/loads to support similar options to json (e.g. object_hook, parse_x, etc) - [ ] dump/dumps to support similar options to json module (e.g. hooks, ensure_ascii, etc) - [ ] string escapes according to quote style

• [ ] support manipulation of json model (e.g. to add/edit comments)

• [ ] dump json model with comments

• [ ] preserve comments when loading json5 (round-trip support)

…

• [ ] Optimize with a C/Cython version

## How fast is it?

It’s nowhere close to the C-optimized json stdlib module. We may get closer to that benchmark if/when we rewrite parts with Cython.

In my own limited testing, as of v0.0.2, this module is about 10-450x slower than the stdlib C-optimized json and about 10-50x slower than the stdlib pure python version of json.

I expect this to slow down marginally when round-trip comment preservation is implemented.