Extended JSON Parser (jsonx)¶

A zero-dependency extended JSON parser that supports JSONC (JSON with Comments), JSONL/NDJSON (newline-delimited JSON), single-line comments (//, #), block comments (/* */), and trailing commas.

Replaces: commentjson, json5 (partial)

Features¶

• Single-line comments: // and # styles
• Block comments: /* ... */ (including multiline)
• Trailing commas: In objects and arrays
• JSONL/NDJSON: Newline-delimited JSON parsing and serialization
• Drop-in replacement: Same API as stdlib json module
• String-safe: Comments inside quoted strings are preserved
• Error reporting: JSONCDecodeError with position information

Quick Start¶

from jsonx import loads, load, dumps, dump

# Parse JSONC string
config = loads("""
{
    // Database settings
    "host": "localhost",
    "port": 5432,  // default PostgreSQL port
    "options": {
        "ssl": true,
        "timeout": 30,  # seconds
    },
}
""")

# Parse JSONC file
with open("config.jsonc") as f:
    config = load(f)

# Serialize (pass-through to json.dumps)
text = dumps(config, indent=2)

API¶

loads(text, **kwargs)¶

Deserialize a JSONC string to a Python object. Strips comments and trailing commas before delegating to json.loads.

All keyword arguments accepted by json.loads are supported (cls, object_hook, parse_float, parse_int, parse_constant, object_pairs_hook).

load(fp, **kwargs)¶

Deserialize a JSONC file-like object. Reads the stream and passes to loads.

dumps(obj, **kwargs) / dump(obj, fp, **kwargs)¶

Pass-through to json.dumps / json.dump for API compatibility.

JSONCDecodeError¶

Subclass of json.JSONDecodeError, raised when JSONC parsing fails.

Comment Styles¶

{
    // C-style single-line comment
    "a": 1,

    # Python-style single-line comment
    "b": 2,

    /* C-style block comment */
    "c": 3,

    /*
     * Multiline
     * block comment
     */
    "d": 4
}

Trailing Commas¶

{
    "array": [1, 2, 3,],
    "nested": {
        "key": "value",
    },
}

Comparison with commentjson¶