UltraJSON

.. image:: https://travis-ci.org/esnme/ultrajson.svg?branch=master :target: https://travis-ci.org/esnme/ultrajson

UltraJSON is an ultra fast JSON encoder and decoder written in pure C with bindings for Python 2.5+ and 3.

For a more painless day to day C/C++ JSON decoder experience please checkout ujson4c_, based on UltraJSON.

.. _ujson4c: http://github.com/esnme/ujson4c/

| Please checkout the rest of the projects in the Ultra series: | http://github.com/esnme/ultramemcache | http://github.com/esnme/ultramysql

To install it just run Pip as usual::

$ pip install ujson

============

Usage

May be used as a drop in replacement for most other JSON parsers for Python::

>>> import ujson
>>> ujson.dumps([{"key": "value"}, 81, True])
'[{"key":"value"},81,true]'
>>> ujson.loads("""[{"key": "value"}, 81, true]""")
[{u'key': u'value'}, 81, True]

~~~~~~~~~~~~~~~ Encoder options ~~~~~~~~~~~~~~~

encodehtmlchars

Used to enable special encoding of "unsafe" HTML characters into safer Unicode sequences. Default is false::

>>> ujson.dumps("<script>John&Doe", encode_html_chars=True)
'"\\u003cscript\\u003eJohn\\u0026Doe"'

ensure_ascii

Limits output to ASCII and escapes all extended characters above 127. Default is true. If your end format supports UTF-8 setting this option to false is highly recommended to save space::

>>> ujson.dumps(u"\xe5\xe4\xf6")
'"\\u00e5\\u00e4\\u00f6"'
>>> ujson.dumps(u"\xe5\xe4\xf6", ensure_ascii=False)
'"\xc3\xa5\xc3\xa4\xc3\xb6"'

double_precision

Controls how many decimals to encode for double or decimal values. Default is 9::

>>> ujson.dumps(math.pi)
'3.1415926536'
>>> ujson.dumps(math.pi, double_precision=1)
'3.1'
>>> ujson.dumps(math.pi, double_precision=0)
'3'
>>> ujson.dumps(math.pi, double_precision=4)
'3.1416'

escapeforwardslashes

Controls whether forward slashes (/) are escaped. Default is True::

>>> ujson.dumps("http://esn.me")
'"http:\/\/esn.me"'
>>> ujson.dumps("http://esn.me", escape_forward_slashes=False)
'"http://esn.me"'

indent

Controls whether indention ("pretty output") is enabled. Default is 0 (disabled)::

>>> ujson.dumps({"foo": "bar"})
'{"foo":"bar"}'
>>> ujson.dumps({"foo": "bar"}, indent=4)
{
    "foo":"bar"
}

~~~~~~~~~~~~~~~~ Decoders options ~~~~~~~~~~~~~~~~

precise_float

Set to enable usage of higher precision (strtod) function when decoding string to double values. Default is to use fast but less precise builtin functionality::

>>> ujson.loads("4.56")
4.5600000000000005
>>> ujson.loads("4.56", precise_float=True)
4.5599999999999996

~~~~~~~~~~~~~ Test machine: ~~~~~~~~~~~~~

Linux 3.13.0-66-generic x86_64 #108-Ubuntu SMP Wed Oct 7 15:20:27 UTC 2015

~~~~~~~~~ Versions: ~~~~~~~~~

CPython 2.7.6 (default, Jun 22 2015, 17:58:13) [GCC 4.8.2]
blist : 1.3.6
simplejson: 3.8.1
ujson : 1.34 (0c52200eb4e2d97e548a765d5f089858c41967b0)
yajl : 0.3.5

+-------------------------------------------------------------------------------+------------+------------+------------+------------+ | | ujson | yajl | simplejson | json | +===============================================================================+============+============+============+============+ | Array with 256 doubles | | | | | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | encode | 3508.19 | 5742.00 | 3232.38 | 3309.09 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | decode | 25103.37 | 11257.83 | 11696.26 | 11871.04 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | Array with 256 UTF-8 strings | | | | | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | encode | 3189.71 | 2717.14 | 2006.38 | 2961.72 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | decode | 1354.94 | 630.54 | 356.35 | 344.05 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | Array with 256 strings | | | | | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | encode | 18127.47 | 12537.39 | 12541.23 | 20001.00 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | decode | 23264.70 | 12788.85 | 25427.88 | 9352.36 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | Medium complex object | | | | | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | encode | 10519.38 | 5021.29 | 3686.86 | 4643.47 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | decode | 9676.53 | 5326.79 | 8515.77 | 3017.30 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | Array with 256 True values | | | | | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | encode | 105998.03 | 102067.28 | 44758.51 | 60424.80 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | decode | 163869.96 | 78341.57 | 110859.36 | 115013.90 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | Array with 256 dict{string, int} pairs | | | | | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | encode | 13471.32 | 12109.09 | 3876.40 | 8833.92 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | decode | 16890.63 | 8946.07 | 12218.55 | 3350.72 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | Dict with 256 arrays with 256 dict{string, int} pairs | | | | | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | encode | 50.25 | 46.45 | 13.82 | 29.28 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | decode | 33.27 | 22.10 | 27.91 | 10.43 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | Dict with 256 arrays with 256 dict{string, int} pairs, outputting sorted keys | | | | | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | encode | 27.19 | | 7.75 | 2.39 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | Complex object | | | | | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | encode | 577.98 | | 387.81 | 470.02 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | decode | 496.73 | 234.44 | 151.00 | 145.16 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+

~~~~~~~~~ Versions: ~~~~~~~~~

CPython 3.4.3 (default, Oct 14 2015, 20:28:29) [GCC 4.8.4]
blist : 1.3.6
simplejson: 3.8.1
ujson : 1.34 (0c52200eb4e2d97e548a765d5f089858c41967b0)
yajl : 0.3.5

+-------------------------------------------------------------------------------+------------+------------+------------+------------+ | | ujson | yajl | simplejson | json | +===============================================================================+============+============+============+============+ | Array with 256 doubles | | | | | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | encode | 3477.15 | 5732.24 | 3016.76 | 3071.99 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | decode | 23625.20 | 9731.45 | 9501.57 | 9901.92 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | Array with 256 UTF-8 strings | | | | | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | encode | 1995.89 | 2151.61 | 1771.98 | 1817.20 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | decode | 1425.04 | 625.38 | 327.14 | 305.95 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | Array with 256 strings | | | | | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | encode | 25461.75 | 12188.64 | 13054.76 | 14429.81 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | decode | 21981.31 | 17014.22 | 23869.48 | 22483.58 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | Medium complex object | | | | | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | encode | 10821.46 | 4837.04 | 3114.04 | 4254.46 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | decode | 7887.77 | 5126.67 | 4934.60 | 6204.97 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | Array with 256 True values | | | | | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | encode | 100452.86 | 94639.42 | 46657.63 | 60358.63 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | decode | 148312.69 | 75485.90 | 88434.91 | 116395.51 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | Array with 256 dict{string, int} pairs | | | | | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | encode | 11698.13 | 8886.96 | 3043.69 | 6302.35 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | decode | 10686.40 | 7061.77 | 5646.80 | 7702.29 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | Dict with 256 arrays with 256 dict{string, int} pairs | | | | | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | encode | 44.26 | 34.43 | 10.40 | 21.97 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | decode | 28.46 | 23.95 | 18.70 | 22.83 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | Dict with 256 arrays with 256 dict{string, int} pairs, outputting sorted keys | | | | | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | encode | 33.60 | | 6.94 | 22.34 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | Complex object | | | | | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | encode | 432.30 | | 351.47 | 379.34 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+ | decode | 434.40 | 221.97 | 149.57 | 147.79 | +-------------------------------------------------------------------------------+------------+------------+------------+------------+