Mailman 3 March 2009 - Python-Dev

Re: [Python-Dev] PEP 372 -- Adding an ordered directory to collections ready for pronouncement
by Hrvoje Niksic 04 Mar '09

04 Mar '09

Steven D'Aprano wrote: > Gisle Aas wrote: > >> Instead of introducing a sorteddict I would instead suggest that the >> future should bring an odict with a sort method; possibly also >> keys_sorted and items_sorted methods. > > Instead of odict.sorted(), that can be spelled: > > sorted(odict) # sort the keys > sorted(odict.values()) # sort the items > sorted(odict.items()) # sort the (key, value) pairs All of these are useful, but not when you want to sort the odict in-place. Since ordered dict is all about order, a method for changing the underlying key order seems quite useful. An odict.sort() would be easy to implement both in the current code (where it would delegate to self._keys.sort()) and in an alternative implementation using a linked list of keys (variants of mergesort work very nicely with linked lists). > The idea of a SortedDict is that it should be sorted at all times, A SortedDict would be nice to have, but we might rather want to use a balanced tree for the its C implementation, i.e. not inherit from dict at all.

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Re: [Python-Dev] PEP 372 -- Adding an ordered directory to collections ready for pronouncement
by Forest 04 Mar '09

04 Mar '09

I'm looking forward to an ordered dictionary in the standard library, especially for things like LRU caches. I was just reading the PEP, and caught this bit: "Does OrderedDict.popitem() return a particular key/value pair? Yes. It pops-off the most recently inserted new key and its corresponding value." Okay, but I'd also like a convenient and fast way to find the oldest entry in an OrderedDict, which I think I'd need for an LRU cache. Skimming the current patch (od7.diff), I didn't notice one. Perhaps I simply missed something. Shouldn't popitem() allow the caller to choose which end from which to pop?

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Re: [Python-Dev] PEP 372 -- Adding an ordered directory to collections ready for pronouncement
by Forest 04 Mar '09

04 Mar '09

Raymond Hettinger wrote: > [Forest] >> Perhaps a new method like getfirst() would be worth while here? > > Guido already gave you a way to access the first item using the existing > API. > Using next(iter(d)) also works. Yep. I think messages are arriving out of order. -1 on my own suggestion.

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Re: [Python-Dev] draft 3.1 release schedule
by Daniel (ajax) Diniz 04 Mar '09

04 Mar '09

Mitchell L Model wrote: > Would whoever is responsible for IDLE please take a look at the patches > I submitted for Python 2 & 3 [tracker IDs 5233 and 5234 respectively]. [...] > I would really like to see them in 3.1. The patch is already there; > someone just has to do whatever gets done with patches to validate it > and check it in. It's not a lot of code changes. Mitchell, thanks for the reports and patches you've been contributing. FWIW, I plan to follow up on these specific issues (and 5276) before 3.1a2, mostly to add tests and a +1 for integration. Regards, Daniel

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[ANN] EuroPython 2009 – Open for Registration and Reminder of Participation!
by Martin P. Hellwig 03 Mar '09

03 Mar '09

On behalf of the EuroPython 2009 organisation it is my privilege and honour to announce that EuroPython 2009 is open for registration! EuroPython is the conference for the communities around Python, including the Django, Zope and Plone communities. This year's conference will be held in Birmingham, UK from Monday 30th June to Monday 2nd July 2009. Preceding the conference, on Saturday 28th June and Sunday 29th June, are the tutorial days, which can be attended separately. We have a special extra early bird rate, just 95 GBP for the conference and 70 GBP for the tutorials. Be quick, this offer only last untill the 14th of March! For your convenience we negotiated special hotel prices, you can book your conference and hotels all at ones. Register at http://www.europython.eu/registration/ . Talks & Themes We already received a number of very interesting talks, why not add yours? Go to http://www.europython.eu/talks/cfp/ for this year's themes and submissions criteria, the deadline is on 5th April 2009. Other Talks, Activities and Events Have you got something which does not fit the above? Visit http://www.europython.eu/talks/ . Help Us Out We could use a hand, any contribution is welcome, please take a look at http://www.europython.eu/contact/ . Sponsors An unique opportunity to affiliate with the prestigious EuroPython conference! http://www.europython.eu/sponsors/ Spread the Word Improve our publicity by distributing this announcement in your corner of the community, coordinating this with the organizers is highly appreciated. http://www.europython.eu/contact/ General Information For more information about the conference, please visit http://www.europython.eu/ . Looking forward to see you! The EuroPython Team

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Interpreter crash in test_strftime?
by Antoine Pitrou 03 Mar '09

03 Mar '09

Hello everybody, I'm trying the current py3k under a Windows virtual machine (with VS Express 2008), and the interpreter crashes in test_strftime in test_datetime.py. Has anyone been getting something like that? (not being a Windows user, it's a bit hard for me to investigate what's wrong) Regards Antoine.

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first 3.1 alpha this Saturday
by Benjamin Peterson 03 Mar '09

03 Mar '09

Hi everyone! The first alpha of 3.1 will be coming out this Saturday, so I would appreciate you not breaking anything too egregiously. :) If you think some thing should hold up the release, mark the issue a release blocker or contact me by email or "gutworth" on #python-dev. I have been talking with Antoine about io in C implementation. We would like to merge the branch before Saturday, so it can get some real world testing. io-c, however, hasn't received much through review. Would somebody have time to go through a diff on Rietveld? On Saturday, I will try to start doing the release around 16:00 UTC. -- Regards, Benjamin

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Instructions on using git mirror
by Neil Schemenauer 03 Mar '09

03 Mar '09

I've revised my instructions on using the experimental git mirror of the Python SVN repository: http://python.ca/nas/tmp/git-notes.txt Stories of success or failure welcome. Neil

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Re: [Python-Dev] ABCs and MRO
by P.J. Eby 03 Mar '09

03 Mar '09

At 09:14 PM 3/2/2009 +0000, Paul Moore wrote: >2009/3/2 Jeffrey Yasskin <jyasskin(a)gmail.com>: > > I tend to think it's a bug in ABCs. You seem to have thought of > > several possible ways to fix it, and I don't have strong preferences > > between them. > >I've discussed ways of fixing simplegeneric, but not of fixing the >issue with ABCs. I'm not sure the ABC "issue" is fixable - after all, >it's by design that ABCs can implement __issubclass__ and "magically" >become superclasses of arbitrary classes as a result. > >I'm not happy about fixing simplegeneric, though, as the whole point >was just to expose an existing implementation, because it might be >generally useful. If we start expanding and enhancing it, there are >better implementations already available on PyPI (better in the sense >of having seen real-world use). And if they don't handle ABCs, then >that might indicate that needing to handle ABCs isn't as vital as this >discussion would seem to imply (but I have no real-world data myself >to make such a claim). I would say it's mainly an annoyance, as long as you have a way to access the method registered for a given ABC, because then you can explicitly register it for types that are being dynamically detected. Now, how widespread an annoyance/FAQ issue it'll be, will depend on: 1. whether the stdlib itself is using GF's and 2. whether those GF's are meaningfully used against ABCs, and 3. how common it is for classes to be "implicit subclasses" of one of those ABCs *and* used with one of those GFs. This sounds like a lot of conditions that have to line up, for it to become an (easily worked-around) annoyance. My inclination is simply to document that it works on explicit type relationships, and note that ABC's and other exotic users of __*check__ methods may require explicit method registrations to work correctly.

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ABCs and simplegeneric use case
by Paul Moore 03 Mar '09

03 Mar '09

2009/3/1 Nick Coghlan <ncoghlan(a)gmail.com>: > As much as I'd like to get a simple generic implementation into > functools, the lack of support for ABCs still bothers me (despite my > last post about that on the tracker item). I'd be a -0 on it going in as > is, but if someone can figure out a clever way of supporting ABCs > without completing killing the invocation speed for generics, that would > go up to a +1. Nick, Armin Ronacher pointed out that it's not likely to be possible to enumerate ABCs even in theory, as ABCs can do semantic checks (e.g. checking for the presence of special methods like __iter__) without needing either inheritance or explicit registration. As you had a genuine use case for simplegeneric, how badly does this limitation damage it? Paul.

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