Mailman 3 December 2000 - Python-Dev

Re: [Python-checkins] CVS: python/dist/src/Objects dictobject.c,2.68,2.69
by Greg Stein 13 Dec '00

13 Dec '00

On Tue, Dec 12, 2000 at 05:02:49PM -0800, Tim Peters wrote: > Update of /cvsroot/python/python/dist/src/Objects > In directory slayer.i.sourceforge.net:/tmp/cvs-serv31776/python/dist/src/objects > > Modified Files: > dictobject.c > Log Message: > Bring comments up to date (e.g., they still said the table had to be > a prime size, which is in fact never true anymore ...). >... > --- 55,78 ---- > > /* > ! There are three kinds of slots in the table: > ! > ! 1. Unused. me_key == me_value == NULL > ! Does not hold an active (key, value) pair now and never did. Unused can > ! transition to Active upon key insertion. This is the only case in which > ! me_key is NULL, and is each slot's initial state. > ! > ! 2. Active. me_key != NULL and me_key != dummy and me_value != NULL > ! Holds an active (key, value) pair. Active can transition to Dummy upon > ! key deletion. This is the only case in which me_value != NULL. > ! > ! 3. Dummy. me_key == dummy && me_value == NULL > ! Previously held an active (key, value) pair, but that was deleted and an > ! active pair has not yet overwritten the slot. Dummy can transition to > ! Active upon key insertion. Dummy slots cannot be made Unused again > ! (cannot have me_key set to NULL), else the probe sequence in case of > ! collision would have no way to know they were once active. 4. The popitem finger. :-) Cheers, -g -- Greg Stein, http://www.lyra.org/

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FW: [Python-Dev] SourceForge: PROJECT DOWNTIME NOTICE
by Tim Peters 12 Dec '00

12 Dec '00

FYI, looks like SourceForge is scheduled to be unusable in a span covering late Friday thru early Saturday (OTT -- One True Time, defined by the clocks in Guido's house). -----Original Message----- From: python-dev-admin(a)python.org [mailto:python-dev-admin@python.org]On Behalf Of Guido van Rossum Sent: Tuesday, December 12, 2000 3:46 PM To: python-dev(a)python.org Subject: [Python-Dev] SourceForge: PROJECT DOWNTIME NOTICE ------- Forwarded Message Date: Tue, 12 Dec 2000 12:38:20 -0800 From: noreply(a)sourceforge.net To: noreply(a)sourceforge.net Subject: SourceForge: PROJECT DOWNTIME NOTICE ATTENTION SOURCEFORGE PROJECT ADMINISTRATORS This update is being sent to project administrators only and contains important information regarding your project. Please read it in its entirety. INFRASTRUCTURE UPGRADE, EXPANSION AND RELOCATION As noted in the sitewide email sent this week, the SourceForge.net infrastructure is being upgraded (and relocated). As part of this projects, plans are underway to further increase capacity and responsiveness. We are scheduling the relocation of the systems serving project subdomain web pages. IMPORTANT: This move will affect you in the following ways: 1. Service and availability of SourceForge.net and the development tools provided will continue uninterupted. 2. Project page webservers hosting subdomains (yourprojectname.sourceforge.net) will be down Friday December 15 from 9PM PST (12AM EST) until 3AM PST. 3. CVS will be unavailable (read only part of the time) from 7PM until 3AM PST 4. Mailing lists and mail aliases will be unavailable until 3AM PST --------------------- This email was sent from sourceforge.net. To change your email receipt preferences, please visit the site and edit your account via the "Account Maintenance" link. Direct any questions to admin(a)sourceforge.net, or reply to this email. ------- End of Forwarded Message _______________________________________________ Python-Dev mailing list Python-Dev(a)python.org http://www.python.org/mailman/listinfo/python-dev

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RE: [Python-Dev] {}.popitem() (was Re: {}.first[key,value,item] ...)
by Moshe Zadka 12 Dec '00

12 Dec '00

On Mon, 11 Dec 2000 15:22:55 -0500, "Tim Peters" <tim.one(a)home.com> wrote: > Well, anyone can play. When keys collide, what we need is a function f(i) > such that repeating > i = f(i) > visits every int in (0, 2**N) exactly once before setting i back to its > initial value, for a fixed N and where the first i is in (0, 2**N). OK, maybe this is me being *real* stupid, but why? Why not [0, 2**n)? Did 0 harm you in your childhood, and you're trying to get back? <0 wink>. If we had an affine operation, instead of a linear one, we could have [0, 2**n). I won't repeat the proof here but changing > def f(i): > i <<= 1 i^=1 # This is the line I added > if i >= 2**N: > i ^= MAGIC_CONSTANT_DEPENDING_ON_N > return i Makes you waltz all over [0, 2**n) if the original made you comple (0, 2**n). if-i'm-wrong-then-someone-should-shoot-me-to-save-me-the-embarrasment-ly y'rs, Z. -- Moshe Zadka <sig(a)zadka.site.co.il> This is a signature anti-virus. Please stop the spread of signature viruses!

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Two new PEPs, 232 & 233
by barry＠digicool.com 12 Dec '00

12 Dec '00

I've just uploaded two new PEPs. 232 is a revision of my pre-PEP era function attribute proposal. 233 is Paul Prescod's proposal for an on-line help facility. http://python.sourceforge.net/peps/pep-0232.html http://python.sourceforge.net/peps/pep-0233.html Let the games begin, -Barry

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SourceForge: PROJECT DOWNTIME NOTICE
by Guido van Rossum 12 Dec '00

12 Dec '00

------- Forwarded Message Date: Tue, 12 Dec 2000 12:38:20 -0800 From: noreply(a)sourceforge.net To: noreply(a)sourceforge.net Subject: SourceForge: PROJECT DOWNTIME NOTICE ATTENTION SOURCEFORGE PROJECT ADMINISTRATORS This update is being sent to project administrators only and contains important information regarding your project. Please read it in its entirety. INFRASTRUCTURE UPGRADE, EXPANSION AND RELOCATION As noted in the sitewide email sent this week, the SourceForge.net infrastructure is being upgraded (and relocated). As part of this projects, plans are underway to further increase capacity and responsiveness. We are scheduling the relocation of the systems serving project subdomain web pages. IMPORTANT: This move will affect you in the following ways: 1. Service and availability of SourceForge.net and the development tools provided will continue uninterupted. 2. Project page webservers hosting subdomains (yourprojectname.sourceforge.net) will be down Friday December 15 from 9PM PST (12AM EST) until 3AM PST. 3. CVS will be unavailable (read only part of the time) from 7PM until 3AM PST 4. Mailing lists and mail aliases will be unavailable until 3AM PST - --------------------- This email was sent from sourceforge.net. To change your email receipt preferences, please visit the site and edit your account via the "Account Maintenance" link. Direct any questions to admin(a)sourceforge.net, or reply to this email. ------- End of Forwarded Message

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Codec aliasing and naming
by M.-A. Lemburg 12 Dec '00

12 Dec '00

I just wanted to inform you of a change I plan for the standard encodings search function to enable better support for aliasing of encoding names. The current implementation caches the aliases returned from the codecs .getaliases() function in the encodings lookup cache rather than in the alias cache. As a consequence, the hyphen to underscore mapping is not applied to the aliases. A codec would have to return a list of all combinations of names with hyphens and underscores in order to emulate the standard lookup behaviour. I have a ptach which fixes this and also assures that aliases cannot be overwritten by codecs which register at some later point in time. This assures that we won't run into situations where a codec import suddenly overrides behaviour of previously active codecs. I would also like to propose the use of a new naming scheme for codecs which enables drop-in installation. As discussed on the i18n-sig list, people would like to install codecs without having the users to call a codec registration function or to touch site.py. The standard search function in the encodings package has a nice property (which I only noticed after the fact ;) which allows using Python package names in the encoding names, e.g. you can install a package 'japanese' and the access the codecs in that package using 'japanese.shiftjis' without having to bother registering a new codec search function for the package -- the encodings package search function will redirect the lookup to the 'japanese' package. Using package names in the encoding name has several advantages: * you know where the codec comes from * you can have mutliple codecs for the same encoding * drop-in installation without registration is possible * the need for a non-default encoding package is visible in the source code * you no longer need to drop new codecs into the Python standard lib Perhaps someone could add a note about this possibility to the codec docs ?! If noone objects, I'll apply the patch for the enhanced alias support later today. Thanks, -- Marc-Andre Lemburg ______________________________________________________________________ Company: http://www.egenix.com/ Consulting: http://www.lemburg.com/ Python Pages: http://www.lemburg.com/python/

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Request review of gdbm patch
by Guido van Rossum 12 Dec '00

12 Dec '00

I'm asking for a review of the patch to gdbm at http://sourceforge.net/patch/?func=detailpatch&patch_id=102638&group_id=5470 I asked the author for clarification and this is what I got. Can anybody suggest what to do? His mail doesn't give me much confidence in the patch. :-( --Guido van Rossum (home page: http://www.python.org/~guido/) ------- Forwarded Message Date: Tue, 12 Dec 2000 13:24:13 +0100 From: Damjan <arhiv(a)freemail.org.mk> To: Guido van Rossum <guido(a)python.org> Subject: Re: your gdbm patch for Python On Mon, Dec 11, 2000 at 03:51:03PM -0500, Guido van Rossum wrote: > I'm looking at your patch at SourceForge: First, I'm sorry it was such a mess of a patch, but I could't figure it out how to send a more elaborate comment. (But then again, I would't have an email from Guido van Rossum in my mail-box, to show of my friends :) > and wondering two things: > > (1) what does the patch do? > > (2) why does the patch remove the 'f' / GDBM_FAST option? From the gdbm info page: ...The following may also be logically or'd into the database flags: GDBM_SYNC, which causes all database operations to be synchronized to the disk, and GDBM_NOLOCK, which prevents the library from performing any locking on the database file. The option GDBM_FAST is now obsolete, since `gdbm' defaults to no-sync mode... ^^^^^^^^ (1) My patch adds two options to the gdbm.open(..) function. These are 'u' for GDBM_NOLOCK, and 's' for GDBM_SYNC. (2) GDBM_FAST is obsolete because gdbm defaults to GDBM_FAST, so it's removed. I'm also thinking about adding a lock and unlock methods to the gdbm object, but it seems that a gdbm database can only be locked and not unlocked. - -- Damjan Georgievski | Дамјан Георгиевски Skopje, Macedonia | Скопје, Македонија ------- End of Forwarded Message

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FW: [Python-Help] indentation
by Tim Peters 11 Dec '00

11 Dec '00

While we're talking about pluggable CLIs, I share this fellow's confusion over IDLE's CLI variant: block code doesn't "look right" under IDLE because sys.ps2 doesn't exist under IDLE. Some days you can't make *anybody* happy <wink>. -----Original Message----- ... Subject: [Python-Help] indentation Sent: Sunday, December 10, 2000 7:32 AM ... My Problem has to do with identation: I put the following to idle: >>> if not 1: print 'Hallo' else: SyntaxError: invalid syntax I get the Message above. I know that else must be 4 spaces to the left, but idle doesn't let me do this. I have only the alternative to put to most left point. But than I disturb the block structure and I get again the error message. I want to have it like this: >>> if not 1: print 'Hallo' else: Can you help me? ...

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PEP 217 - Display Hook for Interactive Use
by Guido van Rossum 10 Dec '00

10 Dec '00

Moshe proposes to add an overridable function sys.displayhook(obj) which will be called by the interpreter for the PRINT_EXPR opcode, instead of hardcoding the behavior. The default implementation will of course have the current behavior, but this makes it much simpler to experiment with alternatives, e.g. using str() instead of repr() (or to choose between str() and repr() based on the type). Moshe has asked me to pronounce on this PEP. I've thought about it, and I'm now all for it. Moshe (or anyone else), please submit a patch to SF that shows the complete implementation! --Guido van Rossum (home page: http://www.python.org/~guido/)

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re: So You Want to Write About Python?
by Greg Wilson 10 Dec '00

10 Dec '00

Hi, folks. Jon Erickson (Doctor Dobb's Journal), Frank Willison (O'Reilly), and I (professional loose cannon) are doing a workshop at IPC on writing books and magazine articles about Python. It would be great to have a few articles (in various stages of their lives) and/or book proposals from people on this list to use as examples. So, if you think the world oughta know about the things you're doing, and would like to use this to help get yourself motivated to start writing, please drop me a line. I'm particularly interested in: - the real-world issues involved in moving to Unicode - non-trivial XML processing using SAX and DOM (where "non-trivial" means "including namespaces, entity references, error handling, and all that") - the theory and practice of stackless, generators, and continuations - the real-world tradeoffs between the various memory management schemes that are now available for Python - feature comparisons of various Foobars that can be used with Python (where "Foobar" could be "GUI toolkit", "IDE", "web scripting toolkit", or just about anything else) - performance analysis and tuning of Python itself (as an example of how you speed up real applications --- this is something that matters a lot in the real world, but tends to get forgotten in school) - just about anything else that you wish someone had written for you before you started your last big project Thanks, Greg

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