6 ms·

Speed tests for *json and cPickle in Python

40 points by j2d2j2d2 16y ago

antlong 16y ago
insane
spenrose 16y ago
He doesn't use the cPickle binary format, which is significantly faster: http://docs.python.org/library/pickle.html#pickle.HIGHEST_PROTOCOL http://docs.python.org/library/pickle.html#pickle.HIGHEST_PR...
- j2d2j2d2 16y ago
  Thanks for pointing this out. I am going to do some follow up tests to cover the advice I got here. I will include this, tnetstrings and decodes too.
  - thezilch 16y ago
    Any interests in also including Google's Protocol Buffers and Facebook's Thrift since it would appear your intentions are to use these blobs in an RPC?
llambda 16y ago
I'm confused, is cjson still recommended? Is it still maintained? Its status seems ambiguous based on the PyPi discussion. Furthermore it seems there's a number of issues with cjson that need to be resolved...
- ericflo 16y ago
  My understanding is that cjson is not recommended or maintained.
- bdarnell 16y ago
  When I tested cjson (~6 months ago?) it had bugs with escaping - strings containing quotes and/or backslashes would be encoded/decoded incorrectly. Not recommended, unless there have been fixes since then.
  - llambda 16y ago
    Based on the PyPi page for cjson, the comments seem to indicate many problems still persist, notwithstanding new updates that have yet to be pushed
- jchrisa 16y ago
  sounds like the kind of project a decent coder could make big improvements on fast
- davvid 16y ago
  Maybe our information is out of date, but here's what we learned: https://github.com/jsonpickle/jsonpickle/commit/0b97652e4102ada4b09994d044812bc22452f70f https://github.com/jsonpickle/jsonpickle/commit/0b97652e4102... jsonpickle: Remove cjson support "First, please don't use cjson for anything. It's got multiple bugs and misfeatures, and is generally unsuited for anything except impressive benchmarks. It was easier to write my own library, from scratch, than try to fix cjson." -- John Millikin, author of jsonlib
  - davvid 16y ago
    Here are some more relevant links: http://news.ycombinator.com/item?id=529104 http://news.ycombinator.com/item?id=529104 http://metaoptimize.com/blog/2009/03/22/fast-deserialization-in-python/ http://metaoptimize.com/blog/2009/03/22/fast-deserialization...
ericflo 16y ago
We were just talking about this a few weeks back, with a few more libraries compared with interesting results: https://convore.com/python/faster-json-library/ https://convore.com/python/faster-json-library/
- j2d2j2d2 16y ago
  demjson looks crazy fast.
d0mine 16y ago
Python 2.7 on Ubuntu: $ python -mtimeit -s "from json import dumps; d = { 'foo': 'bar', 'food': 'barf', 'good': 'bars', 'dood': 'wheres your car?', 'wheres your car': 'dude?', } " "dumps(d)" 100000 loops, best of 3: 6.89 usec per loop $ python -mtimeit -s "from cPickle import dumps; d = { 'foo': 'bar', 'food': 'barf', 'good': 'bars', 'dood': 'wheres your car?', 'wheres your car': 'dude?', } " "dumps(d)" 100000 loops, best of 3: 7.78 usec per loop So `json` seems faster than `cPickle`. Right? Wrong!: $ python -mtimeit -s "from cPickle import dumps; d = { 'foo': 'bar', 'food': 'barf', 'good': 'bars', 'dood': 'wheres your car?', 'wheres your car': 'dude?', } " "dumps(d, -1)" 100000 loops, best of 3: 3.59 usec per loop
- trafficlight 16y ago
  What does the "-1" dump argument mean in 3rd example?
  - kingkilr 16y ago
    It says to use the highest optimization level.
    - d0mine 16y ago
      No. It says use the highest available protocol. The highest available protocol is not necessarily the fastest. There might be other than pure speed reasons to introduce the next Pickle protocol.
  - thezilch 16y ago
    The equivalent of using pickle.HIGHEST_PROTOCOL or pickle.dumps(obj, protocol=pickle.HIGHEST_PROTOCOL) -- any negative value will force highest protocol.
thezilch 16y ago
And because caching systems are typically a means for speeding up reads, where the article only focuses on writes. Python 2.5 -- including pickle's (faster) bin mode Starting simplejson dumps... done: 31.7636611462 Starting cjson encode... done: 3.80062890053 Starting pickle dumps... done: 10.4873199463 Starting pickle dumps (protocol=-1 -- force HIGHEST_PROTOCOL)... done: 5.98110699654 Starting simplejson loads... done: 138.709590197 Starting cjson decode... done: 1.85300803185 Starting pickle loads... done: 5.24735999107 Starting pickle loads (protocol=-1 -- force HIGHEST_PROTOCOL)... done: 3.66428518295
- j2d2j2d2 16y ago
  Great point, thanks.
michaelfairley 16y ago
Apple and oranges (even though they're mostly used for the same thing). pickle is a Turing complete language used to recreate python objects, while json is only used for serialization. pickle is slightly more powerful, but should also not be used to load untrusted data. See http://nadiana.com/python-pickle-insecure http://nadiana.com/python-pickle-insecure

40 points by j2d2j2d2 16y ago

insane

He doesn't use the cPickle binary format, which is significantly faster: http://docs.python.org/library/pickle.html#pickle.HIGHEST_PROTOCOL http://docs.python.org/library/pickle.html#pickle.HIGHEST_PR...

j2d2j2d2 16y ago
Thanks for pointing this out. I am going to do some follow up tests to cover the advice I got here. I will include this, tnetstrings and decodes too.
- thezilch 16y ago
  Any interests in also including Google's Protocol Buffers and Facebook's Thrift since it would appear your intentions are to use these blobs in an RPC?

llambda 16y ago

I'm confused, is cjson still recommended? Is it still maintained? Its status seems ambiguous based on the PyPi discussion. Furthermore it seems there's a number of issues with cjson that need to be resolved...

ericflo 16y ago
My understanding is that cjson is not recommended or maintained.
bdarnell 16y ago
When I tested cjson (~6 months ago?) it had bugs with escaping - strings containing quotes and/or backslashes would be encoded/decoded incorrectly. Not recommended, unless there have been fixes since then.
- llambda 16y ago
  Based on the PyPi page for cjson, the comments seem to indicate many problems still persist, notwithstanding new updates that have yet to be pushed
jchrisa 16y ago
sounds like the kind of project a decent coder could make big improvements on fast
davvid 16y ago
Maybe our information is out of date, but here's what we learned: https://github.com/jsonpickle/jsonpickle/commit/0b97652e4102ada4b09994d044812bc22452f70f https://github.com/jsonpickle/jsonpickle/commit/0b97652e4102... jsonpickle: Remove cjson support "First, please don't use cjson for anything. It's got multiple bugs and misfeatures, and is generally unsuited for anything except impressive benchmarks. It was easier to write my own library, from scratch, than try to fix cjson." -- John Millikin, author of jsonlib
- davvid 16y ago
  Here are some more relevant links: http://news.ycombinator.com/item?id=529104 http://news.ycombinator.com/item?id=529104 http://metaoptimize.com/blog/2009/03/22/fast-deserialization-in-python/ http://metaoptimize.com/blog/2009/03/22/fast-deserialization...

ericflo 16y ago

We were just talking about this a few weeks back, with a few more libraries compared with interesting results: https://convore.com/python/faster-json-library/ https://convore.com/python/faster-json-library/

j2d2j2d2 16y ago
demjson looks crazy fast.

d0mine 16y ago

Python 2.7 on Ubuntu: $ python -mtimeit -s "from json import dumps; d = { 'foo': 'bar', 'food': 'barf', 'good': 'bars', 'dood': 'wheres your car?', 'wheres your car': 'dude?', } " "dumps(d)" 100000 loops, best of 3: 6.89 usec per loop $ python -mtimeit -s "from cPickle import dumps; d = { 'foo': 'bar', 'food': 'barf', 'good': 'bars', 'dood': 'wheres your car?', 'wheres your car': 'dude?', } " "dumps(d)" 100000 loops, best of 3: 7.78 usec per loop So `json` seems faster than `cPickle`. Right? Wrong!: $ python -mtimeit -s "from cPickle import dumps; d = { 'foo': 'bar', 'food': 'barf', 'good': 'bars', 'dood': 'wheres your car?', 'wheres your car': 'dude?', } " "dumps(d, -1)" 100000 loops, best of 3: 3.59 usec per loop

trafficlight 16y ago
What does the "-1" dump argument mean in 3rd example?
- kingkilr 16y ago
  It says to use the highest optimization level.
  - d0mine 16y ago
    No. It says use the highest available protocol. The highest available protocol is not necessarily the fastest. There might be other than pure speed reasons to introduce the next Pickle protocol.
- thezilch 16y ago
  The equivalent of using pickle.HIGHEST_PROTOCOL or pickle.dumps(obj, protocol=pickle.HIGHEST_PROTOCOL) -- any negative value will force highest protocol.

thezilch 16y ago

And because caching systems are typically a means for speeding up reads, where the article only focuses on writes. Python 2.5 -- including pickle's (faster) bin mode Starting simplejson dumps... done: 31.7636611462 Starting cjson encode... done: 3.80062890053 Starting pickle dumps... done: 10.4873199463 Starting pickle dumps (protocol=-1 -- force HIGHEST_PROTOCOL)... done: 5.98110699654 Starting simplejson loads... done: 138.709590197 Starting cjson decode... done: 1.85300803185 Starting pickle loads... done: 5.24735999107 Starting pickle loads (protocol=-1 -- force HIGHEST_PROTOCOL)... done: 3.66428518295

j2d2j2d2 16y ago
Great point, thanks.

michaelfairley 16y ago

Apple and oranges (even though they're mostly used for the same thing). pickle is a Turing complete language used to recreate python objects, while json is only used for serialization. pickle is slightly more powerful, but should also not be used to load untrusted data. See http://nadiana.com/python-pickle-insecure http://nadiana.com/python-pickle-insecure