3 ms·

This benchmark doesn't specify a pickle protocol, which forces Python to use a big, inefficient format. I filed a bug. https://github.com/benfred/bens-blog-co

by jlebar 13y ago

This benchmark doesn't specify a pickle protocol, which forces Python to use a big, inefficient format. I filed a bug. https://github.com/benfred/bens-blog-code/issues/1 https://github.com/benfred/bens-blog-code/issues/1

jfthiigsegbje 13y ago
This is a huge thing he missed. Anyone using pickle for non-trivial work is doing cPickle with PROTOCOL_HIGHEST.
falcolas 13y ago
I also went and tested it. Baseline JSON: -------------------------------------------------------------------------------- JSON packTime 0.612724065781 s - 163205.601975 items/s unpackTime 0.782174110413 s - 127848.772631 items/s size 174.26637 Baseline cPickle, ascii protocol: -------------------------------------------------------------------------------- cPickle packTime 2.41442704201 s - 41417.6938297 items/s unpackTime 0.875658035278 s - 114199.831408 items/s size 286.26637 cPickle, highest protocol: -------------------------------------------------------------------------------- cPickleHP packTime 1.02942800522 s - 97141.3245929 items/s unpackTime 0.583297967911 s - 171438.965162 items/s size 198.26637 For giggles, I evened the playing field and let cPickle at the same data structure as JSON, ascii protocol and highest protocol: -------------------------------------------------------------------------------- cPickleJsonData packTime 0.642832040787 s - 155561.629874 items/s unpackTime 0.478959083557 s - 208786.101847 items/s size 205.53356 -------------------------------------------------------------------------------- cPickleHPjsonData packTime 0.285845041275 s - 349839.897708 items/s unpackTime 0.340456962585 s - 293722.881273 items/s size 175.26637 My conclusions? Serializing dictionaries is easier than serializing objects, and using a non-ascii protocol offers some obvious benefits. JSON is not obviously better than cPickle when comparing apples to apples. It's also worth noting that comparing the json module to the pure python Pickle module isn't a fair fight either; json is at least partially written in C.
- paulgb 13y ago
  I wonder how ujson (pure-C) compares? https://pypi.python.org/pypi/ujson https://pypi.python.org/pypi/ujson

by jlebar 13y ago

jfthiigsegbje 13y ago

This is a huge thing he missed. Anyone using pickle for non-trivial work is doing cPickle with PROTOCOL_HIGHEST.

falcolas 13y ago

I also went and tested it. Baseline JSON: -------------------------------------------------------------------------------- JSON packTime 0.612724065781 s - 163205.601975 items/s unpackTime 0.782174110413 s - 127848.772631 items/s size 174.26637 Baseline cPickle, ascii protocol: -------------------------------------------------------------------------------- cPickle packTime 2.41442704201 s - 41417.6938297 items/s unpackTime 0.875658035278 s - 114199.831408 items/s size 286.26637 cPickle, highest protocol: -------------------------------------------------------------------------------- cPickleHP packTime 1.02942800522 s - 97141.3245929 items/s unpackTime 0.583297967911 s - 171438.965162 items/s size 198.26637 For giggles, I evened the playing field and let cPickle at the same data structure as JSON, ascii protocol and highest protocol: -------------------------------------------------------------------------------- cPickleJsonData packTime 0.642832040787 s - 155561.629874 items/s unpackTime 0.478959083557 s - 208786.101847 items/s size 205.53356 -------------------------------------------------------------------------------- cPickleHPjsonData packTime 0.285845041275 s - 349839.897708 items/s unpackTime 0.340456962585 s - 293722.881273 items/s size 175.26637 My conclusions? Serializing dictionaries is easier than serializing objects, and using a non-ascii protocol offers some obvious benefits. JSON is not obviously better than cPickle when comparing apples to apples. It's also worth noting that comparing the json module to the pure python Pickle module isn't a fair fight either; json is at least partially written in C.

paulgb 13y ago
I wonder how ujson (pure-C) compares? https://pypi.python.org/pypi/ujson https://pypi.python.org/pypi/ujson