Mailman 3 January 2009 - Python-Dev

Fwd: [ALERT] cityoftoronto: problem saving to products table
by Tony Lownds Jan. 24, 2009

Jan. 24, 2009

Hi Paulus, Have you fixed these aerts before? We need a script to fix these alerts. Thanks -Tony Begin forwarded message: > From: support+dev(a)pagedna.com > Date: January 23, 2009 11:00:01 AM PST > To: problems(a)pagedna.com > Subject: [ALERT] cityoftoronto: problem saving to products table > > problem saving to products table > > Traceback (most recent call last): > File "/opt/printra/lib/python/printra/sossite/KindManager.py", line > 325, in … [View More]

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Fwd: [ALERT] cbank: OldHashChecker cannot check password, uid is None
by Tony Lownds Jan. 24, 2009

Jan. 24, 2009

Rob and/or Tim, Can you track this down? Thanks -Tony Begin forwarded message: > From: support+dev(a)pagedna.com > Date: January 23, 2009 11:16:26 AM PST > To: problems(a)pagedna.com > Subject: [ALERT] cbank: OldHashChecker cannot check password, uid is > None > > OldHashChecker cannot check password, uid is None > Script: /inet/www/clients/cbank/index.cgi > Machine: siteserver3 > Directory: /mnt/sitenfs2_clients/cbank >

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Summary of Python tracker Issues
by Python tracker Jan. 24, 2009

Jan. 24, 2009

ACTIVITY SUMMARY (01/16/09 - 01/23/09) 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. 2322 open (+42) / 14538 closed (+32) / 16860 total (+74) Open issues with patches: 790 Average duration of open issues: 701 days. Median duration of open issues: 6 days. Open Issues Breakdown open 2299 (+42) pending 23 ( +0) Issues Created Or Reopened (79) … [View More]

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Single Sign-On for *.python.org
by anatoly techtonik Jan. 23, 2009

Jan. 23, 2009

Hello, Should we open a ticket to make a single sign-on service for *.python.org sites? There are at least 3 logins there may be more, for example if we are going to make some online content edition/comment system for docs. These are: bugs.python.org wiki.python.org pypi.python.org History ~~~~~ Some months ago I filled a proposal to make an OpenID service for http://bugs.python.org http://bugs.python.org/issue2837 Because it was the only python.org service I used, I did not realize that *.… [View More]

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[issue5029] Odd slicing behaviour
by Lambert, David W (S&T) Jan. 23, 2009

Jan. 23, 2009

I cannot find that the documentation states "with negative step swap left with right". This is perhaps non-obvious. It is the words of the tutorial that caused issue 5029 author's confusion. 'a'[0::-1] != [] (is True, author expected False). The tutorial says: "One way to remember how slices work is to think of the indices as pointing between characters, with the left edge of the first character numbered 0. Then the right edge of the last character of a string of n characters has index n, for example:"

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Unable to resolve svn.python.org: OS/X
by Jesse Noller Jan. 23, 2009

Jan. 23, 2009

The other day, Martin pointed out that my buildslave had gone off the reservation: on restarting it via the "buildbot start ~/buildarea" command - Martin noticed the slave had started throwing the DNS resolution error: closing stdin using PTY: True svn: PROPFIND request failed on '/projects/python/branches/py3k' svn: PROPFIND of '/projects/python/branches/py3k': Could not resolve hostname `svn.python.org': Temporary failure in name resolution (http://svn.python.org) program finished with … [View More]

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Questions/comments on documentation formatting
by Brett Cannon Jan. 23, 2009

Jan. 23, 2009

I have been writing up the initial docs for importlib and four things struck me: 1. Why is three space indents the preferred indentation level? 2. Should we start using function annotations? 3. Are brackets for optional arguments (e.g. ``def fxn(a [, b=None [, c=None]])``) really necessary when default argument values are present? And do we really need to nest the brackets when it is obvious that having on optional argument means the rest are optional as well? 4. The var directive is not … [View More]

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PEP 3142: Add a "while" clause to generator expressions
by Gerald Britton Jan. 22, 2009

Jan. 22, 2009

Please find below PEP 3142: Add a "while" clause to generator expressions. I'm looking for feedback and discussion. PEP: 3142 Title: Add a "while" clause to generator expressions Version: $Revision: 68715 $ Last-Modified: $Date: 2009-01-18 11:28:20 +0100 (So, 18. Jan 2009) $ Author: Gerald Britton <gerald.britton(a)gmail.com> Status: Draft Type: Standards Track Content-Type: text/plain Created: 12-Jan-2009 Python-Version: 3.0 Post-History: Abstract This PEP proposes an enhancement … [View More]to generator expressions, adding a "while" clause to complement the existing "if" clause. Rationale A generator expression (PEP 289 [1]) is a concise method to serve dynamically-generated objects to list comprehensions (PEP 202 [2]). Current generator expressions allow for an "if" clause to filter the objects that are returned to those meeting some set of criteria. However, since the "if" clause is evaluated for every object that may be returned, in some cases it is possible that all objects would be rejected after a certain point. For example: g = (n for n in range(100) if n*n < 50) which is equivalent to the using a generator function (PEP 255 [3]): def __gen(exp): for n in exp: if n*n < 50: yield n g = __gen(iter(range(10))) would yield 0, 1, 2, 3, 4, 5, 6 and 7, but would also consider the numbers from 8 to 99 and reject them all since n*n >= 50 for numbers in that range. Allowing for a "while" clause would allow the redundant tests to be short-circuited: g = (n for n in range(100) while n*n < 50) would also yield 0, 1, 2, 3, 4, 5, 6 and 7, but would stop at 8 since the condition (n*n < 50) is no longer true. This would be equivalent to the generator function: def __gen(exp): for n in exp: if n*n < 50: yield n else: break g = __gen(iter(range(100))) Currently, in order to achieve the same result, one would need to either write a generator function such as the one above or use the takewhile function from itertools: from itertools import takewhile g = takewhile(lambda n: n*n < 50, range(100)) The takewhile code achieves the same result as the proposed syntax, albeit in a longer (some would say "less-elegant") fashion. Also, the takewhile version requires an extra function call (the lambda in the example above) with the associated performance penalty. A simple test shows that: for n in (n for n in range(100) if 1): pass performs about 10% better than: for n in takewhile(lambda n: 1, range(100)): pass though they achieve similar results. (The first example uses a generator; takewhile is an iterator). If similarly implemented, a "while" clause should perform about the same as the "if" clause does today. The reader may ask if the "if" and "while" clauses should be mutually exclusive. There are good examples that show that there are times when both may be used to good advantage. For example: p = (p for p in primes() if p > 100 while p < 1000) should return prime numbers found between 100 and 1000, assuming I have a primes() generator that yields prime numbers. Of course, this could also be achieved like this: p = (p for p in (p for p in primes() if p > 100) while p < 1000) which is syntactically simpler. Some may also ask if it is possible to cover dropwhile() functionality in a similar way. I initially thought of: p = (p for p in primes() not while p < 100) but I am not sure that I like it since it uses "not" in a non-pythonic fashion, I think. Adding a "while" clause to generator expressions maintains the compact form while adding a useful facility for short-circuiting the expression. Implementation: I am willing to assist in the implementation of this feature, although I have not contributed to Python thus far and would definitely need mentoring. (At this point I am not quite sure where to begin.) Presently though, I would find it challenging to fit this work into my existing workload. Acknowledgements Raymond Hettinger first proposed the concept of generator expressions in January 2002. References [1] PEP 289: Generator Expressions http://www.python.org/dev/peps/pep-0289/ [2] PEP 202: List Comprehensions http://www.python.org/dev/peps/pep-0202/ [3] PEP 255: Simple Generators http://www.python.org/dev/peps/pep-0255/ Copyright This document has been placed in the public domain. Local Variables: mode: indented-text indent-tabs-mode: nil sentence-end-double-space: t fill-column: 70 coding: utf-8 End: [View Less]

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PEP 8 and constants
by Aahz Jan. 22, 2009

Jan. 22, 2009

In comp.lang.python, there has been some discussion of the fact that there are no guidelines in PEP 8 for constants: http://groups.google.com/group/comp.lang.python/browse_thread/thread/ed964f… Is there any sentiment that PEP 8 should be updated to reflect the common usage of ALL_CAPS for constants? -- Aahz (aahz(a)pythoncraft.com) <*> http://www.pythoncraft.com/ Weinberg's Second Law: If builders built buildings the way programmers wrote programs, then the first … [View More]

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Where is Fred Drake?
by Aahz Jan. 22, 2009

Jan. 22, 2009

Mail to fdrake(a)acm.org is bouncing; I don't know whether it's a temporary failure. Does anyone have another address for him? ----- Forwarded message from Mail Delivery System <MAILER-DAEMON(a)bag.python.org> ----- > Date: Wed, 21 Jan 2009 22:48:49 +0100 (CET) > From: Mail Delivery System <MAILER-DAEMON(a)bag.python.org> > Subject: Undelivered Mail Returned to Sender > To: webmaster(a)python.org > Content-Description: Notification > This is the mail system at … [View More]

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