Wait. Are we talking about the C accelerator or the pure Python implementation of pickle on Python 3?
Victor Le 10 juil. 2017 01:19, "INADA Naoki" <songofaca...@gmail.com> a écrit : > I don't know this is relating to your case. > > When I saw Victor's report [1], I researched why Python 3 is slower than > Python 2 on unpickle_pure_python benchmark. > > [1] https://mail.python.org/pipermail/speed/2017-February/000503.html > > > And I found Python 2 and 3 uses different version of pickle format. > > Current Python 3 uses "framing" format. While unpickling, `read(1)` is > very performance critical. Python 2 uses `cStringIO.read` which is > implemented in C. > On the other hand, Python 3 uses `_Unframer.read` which is implemented > in Python. > > Since this is not relating to "first import time", I don't know this > is what you want to optimize. > (Since _pickle is used for normal case, pure Python unpickle > performance is not a common > problem). > > If you want to optimize it, _Unframer uses BytesIO internally and > performance critical > part may be able to call BytesIO.read directly instead of _Unframer.read. > > Regards, > INADA Naoki <songofaca...@gmail.com> > > > On Sun, Jul 9, 2017 at 11:08 PM, Bhavishya <bhavishyagop...@gmail.com> > wrote: > > Hello, > > > > 1).I was going through the code of python pickle to search any > optimization > > possibility.But the only thing that I found very alarming was again the > > import time(I tried with lazy-import but it didn't helped much.) > > > > I found py3 to be ~45 times slower on initial imports(very raw > > measure..using "time." ) as compared to py2 on an usual example. > > > > py3-> > > ./python -c ' > > favorite_color = { "lion": "yellow", "kitty": "red" } > > pickle.dump( favorite_color, open( "save.p", "wb" ) )' > > 0.009715557098388672(time taken to do initial imports...measured using > > time.time() ) > > > > py2-> > > ./python -c ' > > favorite_color = { "lion": "yellow", "kitty": "red" } > > pickle.dump( favorite_color, open( "save.p", "wb" ) )' > > 0.000236034393311(time taken to do initial imports...measured using > > time.time() ) > > > > Do you have any thought/ideas on improving this? > > > > > > Thank You. > _______________________________________________ > Python-Dev mailing list > Python-Dev@python.org > https://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: https://mail.python.org/mailman/options/python-dev/ > victor.stinner%40gmail.com >
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