jsonesque

jsonesque is a module for processing JSON-like strings into valid, minified JSON. It enables a Python application to support an 'enhanced' form of JSON that contains comments and trailing commas.

For example, given the following JSON-like input:

{
    # This is a Python-style comment
    "a": 1,
    // This is a C-style comment
    "b": 2,
    /*
      This is a multi-line C-style comment
    */
    "c": [
        1,
        2,
        3, // This is a trailing comment pointing out a trailing comma
    ],
}

jsonesque would produce the following valid JSON:

{"a":1,"b":2,"c":[1,2,3]}

This could then be passed into json.loads() or similar.

Usage

Currently, jsonesque exposes just a single function called process(). It takes one argument — a JSON-like string — and returns a new string with the aforementioned enhanced features removed. The string is additionally stripped of extra white-space (minified).

To use jsonesque, simply import jsonesque and call process() on your string:

import json, jsonesque

invalid_json = '[1, 2, /* comment */ 3,]'
valid_json   = jsonesque.process(invalid_json) # Yields string: '[1,2,3]'
decoded      = json.loads(valid_json)          # Yields list:   [1, 2, 3]

jsonesque is smart enough that it won't break on the contents of strings (for example, it correctly handles input like { "//": "/* foo */" }). However, it does not attempt validation — all it does is strip any comments and trailing commas it finds, optimistically assuming that the rest of the input is valid. This means that any other instances of invalid JSON, like single-quotes instead of double-quotes, consecutive commas without a value in an array/object, and so on will make it through the process() call and will break whatever you pass the result into.

Dependencies and compatibility

jsonesque doesn't depend on anything outside the stdlib. It should run on any version of Python 2 (>= 2.2) or Python 3.

Installing, building, and testing

If possible, you should install the package from PyPI using pip or pip3:

pip install jsonesque

If you need to build from source, simply check out the repo and run make and/or make install. To run the unit tests, run make test. If you're on Python 2 and the make commands don't work, you can use python ./setup.py instead.

Credits and licence

jsonesque is heavily based on (i.e., a fork of) JSON.minify. Like JSON.minify, it is available under the MIT licence.

See also

There are a handful of similar projects i found before i started working on this one, all of which have their own advantages and disadvantages:

• JSON.minify — Slightly faster; doesn't support Python-style comments, doesn't support trailing commas, isn't available in PyPI
• Hjson — Extremely featureful, well maintained; just over-kill for my purposes
• json-comment — Probably faster (doesn't use regular expressions), supports INI-style comments and Python-style multi-line strings; doesn't support single-line C-style comments or in-line C-style comments, uses an extremely naïve parsing method, doesn't seem to be maintained
• commentjson — Provides complete re-implementations of json.* functions; possibly slower due to heavier use of regular expressions, doesn't support multi-line/in-line C-style comments, doesn't support trailing commas