Skip to content
Python wrapper around rapidjson
C++ Python Other
Branch: master
Clone or download
Latest commit bc0cd40 Aug 9, 2019
Type Name Latest commit message Commit time
Failed to load latest commit information.
benchmarks Renew the benchmarks tables Jul 23, 2018
docs Introduce a new bytes_mode option to control how bytes instances gets… Aug 6, 2019
rapidjson @ 7484e06 Upgrade underlying RJ library to its current master Feb 11, 2019
tests Test with a bigger dictionaries, with one hundred of keys each Jun 11, 2019
.appveyor.yml Use cibuildwheel 0.10.1 Feb 24, 2019
.dir-locals.el Fix license, and adjust my Emacs setup to use MIT for new files May 11, 2019
.gitlab-ci.yml Use cibuildwheel 0.10.1 Feb 24, 2019
.gitmodules Point rapidjson submodule to Dec 14, 2017
.travis.yml Use cibuildwheel 0.10.2 Mar 17, 2019
CHANGES.rst Release 0.8.0 Aug 9, 2019
LICENSE Add explicit license, authorship and copyright holders to most sources Aug 23, 2017 Hide AppVeyor configuration, to be on par with Travis Apr 25, 2018
Makefile Explicitly set LANG=C executing Sphinx doctest Mar 13, 2019
Makefile.release Use twine to check long description and to upload to PyPI May 11, 2019
Makefile.virtualenv Fix virtualenv creation for Python < 3.6 Sep 10, 2017
README.rst Cosmetic, now the docinfo table should be properly rendered by Warehouse Jul 23, 2018
rapidjson.cpp Introduce a new bytes_mode option to control how bytes instances gets… Aug 6, 2019
requirements-test.txt Fixup 82e4fbf, tests require Sphinx Jul 23, 2018
requirements.txt Use twine to check long description and to upload to PyPI May 11, 2019
setup.cfg Replace pytest's deprecated section name Aug 31, 2016 Use twine to check long description and to upload to PyPI May 11, 2019
tox.ini Extend copyright years Jan 7, 2018
version.txt Release 0.8.0 Aug 9, 2019



Python wrapper around RapidJSON

Authors: Ken Robbins <>
Lele Gaifax <>
License:MIT License
Status: Build status Documentation status

RapidJSON is an extremely fast C++ JSON parser and serialization library: this module wraps it into a Python 3 extension, exposing its serialization/deserialization (to/from either bytes, str or file-like instances) and JSON Schema validation capabilities.

Latest version documentation is automatically rendered by Read the Docs.

Getting Started

First install python-rapidjson:

$ pip install python-rapidjson

or, if you prefer Conda:

$ conda install -c conda-forge python-rapidjson

Basic usage looks like this:

>>> import rapidjson
>>> data = {'foo': 100, 'bar': 'baz'}
>>> rapidjson.dumps(data)
>>> rapidjson.loads('{"bar":"baz","foo":100}')
{'bar': 'baz', 'foo': 100}
>>> class Stream:
...   def write(self, data):
...      print("Chunk:", data)
>>> rapidjson.dump(data, Stream(), chunk_size=5)
Chunk: b'{"foo'
Chunk: b'":100'
Chunk: b',"bar'
Chunk: b'":"ba'
Chunk: b'z"}'


If you want to install the development version (maybe to contribute fixes or enhancements) you may clone the repository:

$ git clone --recursive


The --recursive option is needed because we use a submodule to include RapidJSON sources. Alternatively you can do a plain clone immediately followed by a git submodule update --init.

Alternatively, if you already have (a compatible version of) RapidJSON includes around, you can compile the module specifying their location with the option --rj-include-dir, for example:

$ python3 build --rj-include-dir=/usr/include/rapidjson

A set of makefiles implement most common operations, such as build, check and release; see make help output for a list of available targets.


python-rapidjson tries to be as performant as possible while staying compatible with the json module.

See the this section in the documentation for a comparison with other JSON libraries.


Here are things in the standard json library supports that we have decided not to support:

separators argument
This is mostly used for pretty printing and not supported by RapidJSON so it isn't a high priority. We do support indent kwarg that would get you nice looking JSON anyways.
Coercing keys when dumping
json will stringify a True dictionary key as "true" if you dump it out but when you load it back in it'll still be a string. We want the dump and load to return the exact same objects so we have decided not to do this coercion.
Arbitrary encodings
json.loads() accepts an encoding kwarg determining the encoding of its input, when that is a bytes or bytearray instance. Although RapidJSON is able to cope with several different encodings, we currently support only the recommended one, UTF-8.
You can’t perform that action at this time.