sloppy-json 0.2.0

A forgiving JSON parser that recovers broken JSON from LLM outputs

sloppy-json

A forgiving JSON parser that recovers broken JSON from LLM outputs.

Installation

uv add sloppy-json

or with pip:

pip install sloppy-json

Quick Start

from sloppy_json import parse

# Handles almost any broken JSON (permissive by default)
result = parse("{'name': 'test', 'active': True,}")
# Returns: '{"name": "test", "active": true}'

Usage

from sloppy_json import parse, RecoveryOptions

# Default: permissive parsing (maximum recovery)
result = parse("Here is the JSON: {name: 'test'")  # handles everything

# Strict parsing (standard JSON only)
result = parse('{"key": "value"}', RecoveryOptions(strict=True))

# Custom options
opts = RecoveryOptions(
    allow_single_quotes=True,
    allow_trailing_commas=True,
)
result = parse("{'key': 'value',}", opts)

Features

Feature	Example Input	Output
Single quotes	{'key': 'value'}	{"key": "value"}
Unquoted keys	{key: "value"}	{"key": "value"}
Trailing commas	{"a": 1,}	{"a": 1}
Missing commas	{"a": 1 "b": 2}	{"a": 1, "b": 2}
Python literals	{"flag": True}	{"flag": true}
Truncated JSON	{"key": "val	{"key": "val"}
Code blocks	```json {"a":1}```	{"a": 1}
Comments	{"a": 1} // comment	{"a": 1}
JS undefined	{"a": undefined}	{"a": null}
NaN/Infinity	{"a": NaN}	{"a": "NaN"}

Auto-detection

Automatically detect what options are needed from sample data:

from sloppy_json import parse, RecoveryOptions

samples = ["{'key': 'value',}", "{name: True}"]
options = RecoveryOptions.detect_from(samples)
# options.allow_single_quotes == True
# options.allow_trailing_commas == True
# options.allow_unquoted_keys == True
# options.convert_python_literals == True

result = parse(new_json, options)

Documentation

• Getting Started - Overview and quick start
• Options Reference - All RecoveryOptions explained
• Auto-Detection - Automatically detect required options
• Error Handling - Exceptions and partial recovery
• Examples - Common scenarios and recipes

Similar Projects

• sloppy-xml-py - A sloppy XML parser by Armin Ronacher for handling malformed XML. The naming of this project was inspired by sloppy-xml-py.
• json5 - A JSON extension that allows comments, trailing commas, and unquoted keys.

License

MIT