Mailman 3 December 2012 - pypy-dev

Python vs pypy: interesting performance difference [dict.setdefault]
by David Naylor March 10, 2014

March 10, 2014

Hi, I needed to create a cache of date and time objects and I wondered what was the best way to handle the cache. For comparison I put together the following test: <file="iforkey.py"> import datetime import random import timeit ranges = [datetime.datetime(2011,01, random.randint(1, 31)) for i in xrange(1000)] def ifdict(): cache = {} b = [] for i in ranges: key = i.day if key in cache: b.append(cache[key]) else: date = i.date() cache[key] = date b.append(date) def keydict(): cache = {} b = [] for i in ranges: key = i.day try: b.append(cache[key]) except KeyError: date = i.date() cache[key] = date b.append(date) def defaultdict(): cache = {} b= [] for i in ranges: b.append(cache.setdefault(i, i.date())) print "ifdict:", timeit.repeat("ifdict()", "from __main__ import ifdict", number=10000) print "keydict:", timeit.repeat("keydict()", "from __main__ import keydict", number=10000) print "defaultdict:", timeit.repeat("defaultdict()", "from __main__ import defaultdict", number=10000) </file> # python iforfile.py ifdict: [2.432887077331543, 2.4002890586853027, 2.397233009338379] keydict: [2.3483030796051025, 2.358638048171997, 2.314802885055542] defaultdict: [3.5384328365325928, 3.5329859256744385, 3.5728111267089844] # pypy iforfile.py (pypy 1.5) ifdict: [0.8129069805145264, 0.74648118019104, 0.7432689666748047] keydict: [0.5187451839447021, 0.4662129878997803, 0.4504108428955078] defaultdict: [37.98510789871216, 37.859113931655884, 37.92770600318909] Pypy displays significant slowdown in the defaultdict function, otherwise displays its usual speedup. To check what is the cause I replaced i.date() with i.day and found no major difference in times. It appears dict.setdefault (or it's interaction with jit) is causing a slow down. Regards

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numpy fails trigonometry with complex numbers, what to do?
by Matti Picus Dec. 22, 2013

Dec. 22, 2013

I am trying to complete complex numbers in numpypy. Progress is good, I picked up from previous work on the numpypy-complex2 branch. Complex numbers come with extensive tests, it seems all the corner cases are covered. In porting the tests to numpypy, I came across a problem: numpy returns different results than cmath. Some of the differences are due to the fact that numpy does not raise a ValueError for dividing by 0 or other silly input values, but other differences are inexplicable (note the sign of the imaginary part): >>> numpy.arccos(complex(0.,-0.)) (1.5707963267948966-0j) >>> cmath.acos(complex(0.,-0.)) (1.5707963267948966+0j) >>> or this one: >>> cmath.acos(complex(float('inf'),2.3)) -infj >>> numpy.arccos(complex(float('inf'),2.3)) (0.78539816339744828-inf*j) Should I ignore the inconsistencies, or fix the 700 out of 2300 test instance failures? What should pypy's numpypy do - be consistent with numpy or with cmath? cmath is easier and probably faster (no need to mangle results or input args), so I would prefer cmath to trying to understand the logic behind numpy. Matti 2280c2365844

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(unexpectedly) bad performance of stackless and greenlet on PyPy
by Denis Bilenko Jan. 31, 2013

Jan. 31, 2013

Hi! I've micro-benchmarked stackless and greenlet module in PyPy and was quite surprised with the results. According to this benchmark stackless.channel is 100x times slower on PyPy (vs Stackless) and greenlet is 20x times slower on PyPy (vs CPython). https://gist.github.com/4412582 Is this a bug in benchmark (or PyPy) or is it the expected current state of stackless features on PyPy? Cheers, Denis.

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Re: [pypy-dev] [pypy-commit] pypy default: Do sign checks directly.
by Carl Friedrich Bolz Dec. 29, 2012

Dec. 29, 2012

Hi Stian, Could the sign check be please put into a nice helper method on rbigint objects? I find it not so nice that longobject.py pokes around in the internals of the big integer implementation. Cheers, Carl Friedrich On 11/05/2012 03:43 PM, Stian Andreassen wrote: > Author: Stian Andreassen > Branch: > Changeset: r58761:bc1b37bec5b3 > Date: 2012-11-05 23:41 +0100 > http://bitbucket.org/pypy/pypy/changeset/bc1b37bec5b3/ > > Log: Do sign checks directly. > > diff --git a/pypy/objspace/std/longobject.py b/pypy/objspace/std/longobject.py > --- a/pypy/objspace/std/longobject.py > +++ b/pypy/objspace/std/longobject.py > @@ -251,7 +251,7 @@ > > def pow__Long_Long_Long(space, w_long1, w_long2, w_long3): > # XXX need to replicate some of the logic, to get the errors right > - if w_long2.num.lt(rbigint.fromint(0)): > + if w_long2.num.sign < 0: > raise OperationError( > space.w_TypeError, > space.wrap( > @@ -265,7 +265,7 @@ > > def pow__Long_Long_None(space, w_long1, w_long2, w_long3): > # XXX need to replicate some of the logic, to get the errors right > - if w_long2.num.lt(rbigint.fromint(0)): > + if w_long2.num.sign < 0: > raise FailedToImplementArgs( > space.w_ValueError, > space.wrap("long pow() too negative")) > @@ -288,7 +288,7 @@ > > def lshift__Long_Long(space, w_long1, w_long2): > # XXX need to replicate some of the logic, to get the errors right > - if w_long2.num.lt(rbigint.fromint(0)): > + if w_long2.num.sign < 0: > raise OperationError(space.w_ValueError, > space.wrap("negative shift count")) > try: > @@ -300,7 +300,7 @@ > > def rshift__Long_Long(space, w_long1, w_long2): > # XXX need to replicate some of the logic, to get the errors right > - if w_long2.num.lt(rbigint.fromint(0)): > + if w_long2.num.sign < 0: > raise OperationError(space.w_ValueError, > space.wrap("negative shift count")) > try: > _______________________________________________ > pypy-commit mailing list > pypy-commit(a)python.org > http://mail.python.org/mailman/listinfo/pypy-commit >

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Independen Spcoal Network
by Independent Social Network Dec. 28, 2012

Dec. 28, 2012

HE Babylon* Independen Social Network http://www.hebabylon.com/

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Config value owner
by anatoly techtonik Dec. 26, 2012

Dec. 26, 2012

What is the meaning of value owner in Config class? It prevents useful debugging output from displaying (like --help option, which doesn't work for translator.py on my machine due to missing compiler traceback). https://bitbucket.org/pypy/pypy/src/36abd0dd07d468456e1acb2565f0b59979ed144… -- anatoly t.

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Re: [pypy-dev] PyPy in getting started
by William ML Leslie Dec. 24, 2012

Dec. 24, 2012

Ugh, hit the wrong reply button. On 24 December 2012 19:24, William ML Leslie <william.leslie.ttg(a)gmail.com> wrote: > On 24 December 2012 19:03, anatoly techtonik <techtonik(a)gmail.com> wrote: >> Hi, >> >> The PyPy description in getting started is still too scientific. I attach a >> patch with accessibility fix. =) But it is still not completely clear if >> PyPy's Python implementation is written in Python or in RPython? > > They aren't mutually exclusive; all rpython is python. > >> '''And the second is one particular implementation that is so generated – an >> implementation of the Python programming language written in Python >> itself.''' > > Maybe we could be even clearer - in my mind, implementations aren't > generated, they do have to be written (: > >> If Python implementation is written in Python, and not in RPython then there >> is the missing link between the framework and implementation, which is >> confusing. >> >> http://doc.pypy.org/en/latest/getting-started.html#what-is-pypy >> -- >> anatoly t. > > -- > William Leslie -- William Leslie

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PyPy in getting started
by anatoly techtonik Dec. 24, 2012

Dec. 24, 2012

Hi, The PyPy description in getting started is still too scientific. I attach a patch with accessibility fix. =) But it is still not completely clear if PyPy's Python implementation is written in Python or in RPython? '''And the second is one particular implementation that is so generated – an implementation of the Python programming language written in Python itself.''' If Python implementation is written in Python, and not in RPython then there is the missing link between the framework and implementation, which is confusing. http://doc.pypy.org/en/latest/getting-started.html#what-is-pypy -- anatoly t.

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pypy services hosting / action needed!
by holger krekel Dec. 21, 2012

Dec. 21, 2012

Hi folks, for the last several years i cared for hosting these pypy services: - pypy.org (static generated html) - bugs.pypy.org (roundup instance, postfix server) - speed.python.org (django app) These services are living on two rented servers which cost me per-month and i am finally getting rid of them in January 2013. IIRC Maciej and others had various ideas (last year) on where the pypy services could better live. Any progress on this? ASFAIK the PSF is willing to offer a VM that we could use, at least for pypy.org and bugs.pypy.org. However, i haven't yet heart back from Noah Kantrowitz. I contacted him twice in recent weeks. If somebody has other contacts to try, go ahead and maybe CC me to avoid chaos. Note that i actually don't want to drive these efforts but offer my help in helping to migrate. I'd be happy if the currently active pypy devs determine a plan of action and drive it. best, holger

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a question about pypy-sandbox
by 周灿 Dec. 21, 2012

Dec. 21, 2012

Hi,all I want to creat a sandbox to run untrust code. And I choose pypy and I have immplemented my RPC server. But i feel puzzled pypy sandbox is not compatible with all the standard libs(such as threading), since pypy does not allow interperter to load native C modules. I want to know why pypy doesn't allow enve standard libs load C modules, then untrust code can not use some standard libs. And if it's proper that I support some modules such as threading.py by allow interperter to load c modules for threading.py? Zhoucan with Chinese English

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