Python 2.6 JSON decoding performance

The new Yajl - Yet Another JSON Library is very fast.

yajl        serialize: 0.180  deserialize: 0.182  total: 0.362
simplejson  serialize: 0.840  deserialize: 0.490  total: 1.331
stdlib json serialize: 2.812  deserialize: 8.725  total: 11.537

You can compare the libraries yourself.

Update: UltraJSON is even faster.

It may vary by platform, but the builtin json module is based on simplejson, not including the C speedups. I've found simplejson to be as a fast as python-cjson anyway, so I prefer it since it obviously has the same interface as the builtin.

try:
    import simplejson as json
except ImportError:
    import json

Seems to me that's the best idiom for awhile, yielding the performance when available while being forwards-compatible.

I was parsing the same file 10x. File size was 1,856,944 bytes.

Python 2.6:

yajl        serialize: 0.294  deserialize: 0.334  total: 0.627
cjson       serialize: 0.494  deserialize: 0.276  total: 0.769
simplejson  serialize: 0.554  deserialize: 0.268  total: 0.823
stdlib json serialize: 3.917  deserialize: 17.508 total: 21.425

Python 2.7:

yajl        serialize: 0.289  deserialize: 0.312  total: 0.601
cjson       serialize: 0.232  deserialize: 0.254  total: 0.486
simplejson  serialize: 0.288  deserialize: 0.253  total: 0.540
stdlib json serialize: 0.273  deserialize: 0.256  total: 0.528

Not sure why numbers are disproportionate from your results. I guess, newer libraries?