python-rapidjson 0.0.8

Python wrapper around rapidjson

Python wrapper around RapidJSON. RapidJSON is an extremely fast C++ json serialization library.

We do not support legacy python versions, you will need to upgrade to Python 3 to use this library.

Getting Started

First install python-rapidjson:

$ pip install python-rapidjson

RapidJSON tries to be compatible with the standard library json module so it should be a drop in replacement. Basic usage looks like this:

>>> import rapidjson
>>> data = {'foo': 100, 'bar': 'baz'}
>>> rapidjson.dumps(data)
'{"bar":"baz","foo":100}'
>>> rapidjson.loads('{"bar":"baz","foo":100}')
{'bar': 'baz', 'foo': 100}

Performance

python-rapidjson tries to be as performant as possible while staying compatible with the json module. Here are our current benchmarks:

	ujson	simplejson	rapidjson	yajl
Array with 256 doubles
Encode	13.81s	12.58s	1.82s	8.36s
Decode	2.00s	4.65s	2.19s	2.09s
Array with 256 utf-8 strings
Encode	1.98s	2.36s	5.09s	1.45s
Decode	2.77s	13.58s	2.42s	7.19s
100 dictionaries of 100 arrays
Encode	1.65s	5.20s	0.77s	2.09s
Decode	2.76s	3.86s	2.79s	3.47

To run these tests yourself, clone the repo and run:

$ tox -e py34 -- -m benchmark --compare-other-engines

Without the option --compare-other-engines it will focus only on RapidJSON. This is particularly handy coupled with the compare past runs functionality of pytest-benchmark:

$ tox -e py34 -- -m benchmark --benchmark-autosave
# hack, hack, hack!
$ tox -e py34 -- -m benchmark --benchmark-compare=0001

----------------------- benchmark 'deserialize': 18 tests ------------------------
Name (time in us)                                                            Min…
----------------------------------------------------------------------------------
test_loads[rapidjson-256 Trues array] (NOW)                         5.2320 (1.0)…
test_loads[rapidjson-256 Trues array] (0001)                        5.4180 (1.04)…
…

Incompatibility

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 turn True into '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 coercing.