Mailman 3 June 2007 - Python-Dev

Santa Fe Python Day report
by Facundo Batista June 11, 2007

June 11, 2007

It was very succesful, around +300 people assisted, and there were a lot of interesting talks (two introductory talks, Turbogears, PyWeek, Zope 3, security, creating 3D games, Plone, automatic security testings, concurrency, and programming the OLPC). I want to thanks the PSF for the received support. Python is developing interestingly in Argentina, and this Python Days are both a prove of that, and a way to get more Python developers. Some links: Santa Fe Python Day: http://www.python-… [View More]

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Instance variable access and descriptors
by Eyal Lotem June 11, 2007

June 11, 2007

Hi. I was surprised to find in my profiling that instance variable access was pretty slow. I looked through the CPython code involved, and discovered something that really surprises me. Python, probably through the valid assumption that most attribute lookups go to the class, tries to look for the attribute in the class first, and in the instance, second. What Python currently does is quite peculiar! Here's a short description o PyObject_GenericGetAttr: A. Python looks for a descriptor in … [View More]

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Re: [Python-Dev] zipfile and unicode filenames
by "Martin v. Löwis" June 11, 2007

June 11, 2007

> sys.setdefaultencoding() > exists for a reason, wouldn't it be better if stdlib could cope with > that at least with zipfile? sys.setdefaultencoding just does not work. Many more things break when you call it. It only exists because people like you insisted that it exists. > Also note that I'm trying to ask if zipfile should be improved, how it > should be improved, and this possible improvement is not even for me > (because now I know how zipfile behaves and I will work … [View More]

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Frame zombies
by Eyal Lotem June 11, 2007

June 11, 2007

I was just looking through the code that handles frames (as part of my current effort to determine how to improve on CPython's performance), when I noticed the freelist/zombie mechanism for frame allocation handling. While the zombie mechanism seems like a nice optimization, I believe there can be a couple of improvements. Currently, each code object has a zombie frame that last executed it. This zombie is reused when that code object is re-executed in a frame. When a frame is released, it is … [View More]

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Re: [Python-Dev] Fwd: Instance variable access and descriptors
by Phillip J. Eby June 10, 2007

June 10, 2007

At 11:27 AM 6/10/2007 +0100, Gustavo Carneiro wrote: > I have to agree with you. If removing support for > self.__dict__['propertyname'] (where propertyname is also the name > of a descriptor) is the price to pay for significant speedup, so be > it. People doing that are asking for trouble anyway! How so? This order of lookup is explicitly defined by the precedence rules of PEP 252: """When a dynamic attribute (one defined in a regular object's __dict__) has the same name … [View More]

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Re: [Python-Dev] Fwd: Instance variable access and descriptors
by Phillip J. Eby June 10, 2007

June 10, 2007

At 04:14 AM 6/10/2007 +0300, Eyal Lotem wrote: >On 6/10/07, Phillip J. Eby <pje(a)telecommunity.com> wrote: > > At 12:23 AM 6/10/2007 +0300, Eyal Lotem wrote: > > >A. It will break code that uses instance.__dict__['var'] directly, > > >when 'var' exists as a property with a __set__ in the class. I believe > > >this is not significant. > > >B. It will simplify getattr's semantics. Python should _always_ give > > >precedence to instance … [View More]

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Fwd: Instance variable access and descriptors
by Eyal Lotem June 10, 2007

June 10, 2007

On 6/10/07, Phillip J. Eby <pje(a)telecommunity.com> wrote: > At 12:23 AM 6/10/2007 +0300, Eyal Lotem wrote: > >A. It will break code that uses instance.__dict__['var'] directly, > >when 'var' exists as a property with a __set__ in the class. I believe > >this is not significant. > >B. It will simplify getattr's semantics. Python should _always_ give > >precedence to instance attributes over class ones, rather than have > >very weird special-cases (… [View More]

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zipfile and unicode filenames
by Alexey Borzenkov June 10, 2007

June 10, 2007

Hi everyone, Today I've stumbled upon a bug in my program that wasn't very straightforward to understand. The problem is that I was passing unicode filenames to zipfile.ZipFile.write and I had sys.setdefaultencoding() in effect, which resulted in a situation where most of the bytes generated in zipfile.ZipInfo.FileHeader would pass thru, except for a few, which caused codec error on another machine (where filenames got infectiously upgraded to unicode). The problem here is that it was … [View More]

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Summary of Tracker Issues
by Tracker June 10, 2007

June 10, 2007

ACTIVITY SUMMARY (06/03/07 - 06/10/07) Tracker at http://bugs.python.org/ To view or respond to any of the issues listed below, click on the issue number. Do NOT respond to this message. 1645 open ( +0) / 8584 closed ( +0) / 10229 total ( +0) Average duration of open issues: 822 days. Median duration of open issues: 770 days. Open Issues Breakdown open 1645 ( +0) pending 0 ( +0) Issues Now Closed (1) _____________________ New issue test for email … [View More]

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Re: [Python-Dev] Instance variable access and descriptors
by Steven Bethard June 9, 2007

June 9, 2007

> On 6/10/07, Steven Bethard <steven.bethard(a)gmail.com> wrote: > > On 6/9/07, Eyal Lotem <eyal.lotem(a)gmail.com> wrote: > > > I believe that this should be changed, so that Python first looks for > > > the attribute in the instance's dict and only then through the dict's > > > mro. > > > > Are you suggesting that the following code should print "43" instead of "42"? > > :: > > > > >>> class C(object): … [View More]

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