pyjson5

A Python implementation of the JSON5 data format.

JSON5 extends the JSON data interchange format to make it slightly more usable as a configuration language:

JavaScript-style comments (both single and multi-line) are legal.
Object keys may be unquoted if they are legal ECMAScript identifiers
Objects and arrays may end with trailing commas.
Strings can be single-quoted, and multi-line string literals are allowed.

There are a few other more minor extensions to JSON; see the above page for the full details.

This project implements a reader and writer implementation for Python; where possible, it mirrors the standard Python JSON API package for ease of use.

This is an early release. It has been reasonably well-tested, but it is SLOW. It can be 1000-6000x slower than the C-optimized JSON module, and is 200x slower (or more) than the pure Python JSON module.

Known issues

Did I mention that it is SLOW?
The implementation follows Python3's json implementation where possible. This means that the encoding method to dump() is ignored, and unicode strings are always returned.
The cls keyword argument that json.load()/json.loads() accepts to specify a custom subclass of JSONDecoder is not and will not be supported, because this implementation uses a completely different approach to parsing strings and doesn't have anything like the JSONDecoder class.
The cls keyword argument that json.dump()/json.dumps() accepts is also not supported, for consistency with json5.load(). The default keyword is supported, though, and might be able to serve as a workaround.