Mailman 3 April 2010 - Python-Dev

Re: [Python-Dev] [PEP 3148] futures - execute computations asynchronously
by P.J. Eby May 2, 2010

May 2, 2010

At 10:59 AM 3/7/2010 -0800, Jeffrey Yasskin wrote: >So is it that you just don't like the idea of blocking, and want to >stop anything that relies on it from getting into the standard library? Um, no. As I said before, call it a "parallel task queue" or "parallel task manager" or something to that general effect and I'm on board. It may not be in the Zen of Python, but ISTM that names should generally follow use cases. It is something of a corollary to "one obvious way to do it", … [View More]in that if you see something whose name matches what you want to do, then it should be obvious that that's the way in question. ;-) The use cases for "parallel task queues", however, are a subset of those for "futures" in the general case. Since the proposed module addresses most of the former but very little of the latter, calling it futures is inappropriate. Specifically, it's: 1. Confusing to people who don't know what futures are (see e.g R.D. Murray's post), and 2. Underpowered for people who expect/want a more fully-featured futures system along the lines of E or Deferreds. It seems that the only people for whom it's an intuitively correct description are people who've only had experience with more limited futures models (like Java's). However, these people should not have a problem understanding the notion of parallel task queueing or task management, so changing the name isn't really a loss for them, and it's a gain for everybody else. > Given the set_result and set_exception methods, it's pretty > straightforward to fill in the value of a future from something > that isn't purely computational. Those are described as "internal" methods in the PEP; by contrast, the Deferred equivalents are part of the public API. > Given a way to register "on-done" callbacks with the future, it > would be straightforward to wait for a future without blocking, too. Yes, and with a few more additions besides that one, you might be on the way to an actual competitor for Deferreds. For example: retry support, chaining, logging, API for transparent result processing, coroutine support, co-ordination tools like locks, sempaphores and queues, etc. These are all things you would very likely want or need if you actually wanted to write a program using futures as *your main computational model*, vs. just needing to toss out some parallel tasks in a primarily synchronous program. Of course, Deferreds are indeed overkill if all you're ever going to want is a few parallel tasks, unless you're already skilled in using Twisted or some wrapper for it. So, I totally support having a simple task queue in the stdlib, as there are definitely times I would've used such a thing for a quick script, if it were available. However, I've *also* had use cases for using futures as a computational model, and so that's what I originally thought this PEP was about. After the use cases were clarified, though, it seems to me that *calling* it futures is a bad idea, because it's really just a nice task queuing system. I'm +1 on adding a nice task queuing system, -1 on calling it by any other name. ;-) [View Less]

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patch for review: __import__ documentation
by Chris Jerdonek April 30, 2010

April 30, 2010

Here is another patch for review: http://bugs.python.org/issue8370 This is a trivial fix to the 2.6 and 2.7 documentation. Thanks, --Chris

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Summary of Python tracker Issues
by Python tracker April 30, 2010

April 30, 2010

ACTIVITY SUMMARY (2010-04-23 - 2010-04-30) Python 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. 2638 open (+41) / 17759 closed (+27) / 20397 total (+68) Open issues with patches: 1081 Average duration of open issues: 724 days. Median duration of open issues: 494 days. Open Issues Breakdown open 2620 (+41) languishing 10 ( +0) pending 7 ( +0) Issues Created Or … [View More]

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Fwd: Broken link to download (Mac OS X)
by webmaster＠python.org April 30, 2010

April 30, 2010

Hey all, This seems to happen whenever we do a new release (we've had a couple of emails to webmaster(a)python.org about it since 2.6.5 was released). The main download page for Python has a broken link for the Mac installer (because it hasn't been built yet I assume): http://python.org/download/ The link 404s, with no explanation or alternate link - so for the casual user who wants to install Python 2.6 on Mac OS X they are sorely-out-of-luck. Not being able to provide a mac … [View More]

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bug tracker permissions request
by Daniel Stutzbach April 30, 2010

April 30, 2010

May I have enhanced permissions on the bug tracker, so that I can perform the following tasks? - Assign issues to myself that I plan to write a patch for - Update the Stage to "patch review" after writing a patch - Occasional bug triage My login name on the tracker is "stutzbach". I only find the time to produce patches once in awhile, but when I have the time I usually produce more than one. Assigning bugs to myself will increase my motivation to write patches, as I will feel that I've … [View More]

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array matching
by Bill Jordan April 30, 2010

April 30, 2010

Hey guys, I am sorry if this is not the right list to post some questions. I have a simple question please and would appreciate some answers as I am new to Python. I have 2 D array: test = [[A,1],[B,2],[A,3][B,4]] I want to arrang this array in different arrays so each one will have what is attached to. For example I want the output: A =[1,3] and B=[2,4] Thanks, Bill

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Make 'normal' the default tracker priority level
by Terry Reedy April 28, 2010

April 28, 2010

Currently, the 'default' Priority for new tracker issues is '- no selection -'. This is, I believe, widely understood to be equivalent to 'normal'. Consequently, almost no one bothers to make a selection. This applies even to experienced people like (in the last hour) Jesus Crea (#8536), Eric Smith (*8538), and Mark Dickenson (*8540). If possible, I think 'normal' should be the default in the hox or else there should be some sort of auto replacement. Currently, there are tracker … [View More]

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what to do if you don't want your module in Debian
by Piotr Ożarowski April 27, 2010

April 27, 2010

Hi, Many Python module developers do not want their work to be distributed by Debian (and probably by other Linux distributions), here's a list of hints that will help you accomplish that goal: * depend on unstable or unreleased software (even if you use it only to generate docs or do unit tests), * bundle local copies of 3rd party modules and do not send your changes upstream, never document your changes in upstream code, * break API in every release, * break ABI in every second release, … [View More]

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Drop OS/2 support?
by Victor Stinner April 26, 2010

April 26, 2010

Hi, Python contains code specific to OS/2 (eg. see Modules/posixmodule.c). I read in Wikipedia that IBM has discontinued OS/2 support in 2005. Do we still support OS/2 or not? I'm asking because I'm working on a patch modifying OS2 specific code, but I'm unable to compile nor test my changes. And on IRC we told me that nobody knows/uses OS/2. If we support OS/2, we need a buildbot. My patch: http://bugs.python.org/issue8391 (os.execvpe() doesn't support surrogates in env). -- Victor … [View More]

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argparse suggestion
by Neal Becker April 26, 2010

April 26, 2010

steven.bethard(a)gmail.com made a very nice module for me to enhance argparse called argparse_bool.py, which contains ConfigureAction. This will allow a boolean value to be set very like the gnu configure style: --foo --with-foo --without-foo --no-foo --foo=yes --foo=no I've been happily using it, and I think it would be of sufficient general interest to include it with the standard library.

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