🌐 Mailman 3 April 2004 - Python-list - python.org

Microsoft making Python.NET
by Greg April 1, 2004

April 1, 2004

The following article from microsoft describes a workaroind for a bug in hte beta version of VISUAL PYTHON DOT NET http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnaskdr/ht… When did microsoft put python into the visual studio beta? How did this not make big news in developmnt circles? A.E. Here is the body of the article: FIX: Memory Leak after pickling in Visual Python .NET Beta 1 View products that this article applies to. This article was previously published under Q114345321 IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base: 114345321/8 Description of the Microsoft Windows Registry SYMPTOMS When pickling an object containing a cyclic graph, the Visual Python .NET Beta 1 can create references that will not be garbage collected. CAUSE Visual Python .NET Beta 1 does not impose a recursion limit by default. In this mode, an objects references are evaluated lazily durring pickling. If the garbage collector runs durring this process, some objects can be incorrectly referenced. The failure is due to registry key data that was installed by Visual Python .NET Beta 1. RESOLUTION WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk. Open Regedit.exe and browse to HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\8.0\P++\RecursionLimit. To be safe, back up this registry key: From the File menu, click Export and save the key to an .reg file. Set the RecusionLimit key from 0 to 1000. STATUS Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article. This bug will be corrected in Visual Python .NET (2004). The information in this article applies to: Microsoft Visual Studio .NET 8.0, Beta 1

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RE: splitting one dictionary into two
by Robert Brewer April 1, 2004

April 1, 2004

jsaul wrote: > I have to split a dict into two dicts. Depending on their values, > the items shall remain in the original dict or be moved to another > one and at the same time be removed from the original dict. > > OK, this is how I do it right now: > > dict1 = { "a":1, "b":3, "c":5, "d":4, "e":2 } > dict2 = {} > klist = [] > > for key in dict1: > if dict1[key] > 3: # some criterion > dict2[key] = dict1[key] > klist.append(key) > > for key in klist: > del dict1[key] > > print dict1 > print dict2 > > That means that I store the keys of the items to be removed from > the original dict in a list (klist) and subsequently remove the > items using these keys. > > Is there an "even more pythonic" way? I'm not sure about "more Pythonic", but this is another way, which iteratively destroys the original dict and produces two new ones: def cleave(mapping, truthfunc): dict1, dict2 = {}, {} while mapping: key, value = mapping.popitem() if truthfunc(key, value): dict1[key] = value else: dict2[key] = value return dict1, dict2 HTH Robert Brewer MIS Amor Ministries fumanchu(a)amor.org

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Re: ANNOUNCE: 'goto' for Python
by Camilo Olarte April 1, 2004

April 1, 2004

>> Entrian Solutions is pleased to announce version 1.0 of the 'goto' >> module. >> >> This adds the 'goto' and 'comefrom' keywords to Python 2.3, adding >> flexibility to Python's control flow mechanisms and allowing Python >> programmers to use many common control flow idioms that were previously >> denied to them. >>>>>> What is the day today ? Oh yes the first of April ! <<<<<< OOUCH ! I Almost believe it! :) Camilo Olarte Telesat, más fácil...más Internet. http://www.telesat.com.co/

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Re: Followup: big projects, games, reload
by Arthur April 1, 2004

April 1, 2004

On Wed, 31 Mar 2004 14:32:47 -0500, "Terry Reedy" <tjreedy(a)udel.edu> wrote: >People fairly frequently ask about Python being used in big projects, >commercial projects, commercial games, etc. There was also a recent thread >on the limitations of 'reload' and what one might do to get the reload >behavior one wants... > >One of the PyCon talks that most surprised *me* is this: >http://www.python.org/pycon/dc2004/papers/29/Panda3D.htm It surprised me as well. But for different reasons. The Entertainment Technology Center at CMU seemed to have been (is?) ground zero for Alice. And Disney, is well, Disney. And the Alan Kay, Disney connection - as to *educational* technology, disturbed me - to put it mildly. I could say much on this. So it was great to see that collaboration of Disney and CMU produce something so clearly defined and powerful and - well - wholesome. It was refreshing that: Panda3d - as opposed to, Alice -is and has been opened source and crossplatform. It is and understands itself to be *entertainment* technology. No ambiguity, and not depending on who the audience happens to be. The students at CMU in the Building Virtual World class were given the choice of Alice and Panda3d and 100% chose to work with Panda3d. The class project usingt Panda3d presented seemed to me, at least, to be a clear swipe at the insipidness of Alice. The Python community should feel good about Disney's choice of Python as the scripting tools for Panda3d. And CMU support for the project going forward. Buy the community should intorspect a bit, IMO, about how so many bright people seemed to have become enamored of Alice, simultaneously. I will probably never get over the fact that a (let's say) overly generous view of Alice seemed to be almost of price of admission for community acceptance for those of us interested in Python and education. Art > >It seems that Disney's rather successful ToonTown Online ( >http://toontown.com ) >is scripted in Python on top of their now open sourced Panda3D (C++) >engine. >( http://www.etc.cmu.edu/panda3d ) >This answers the first set of questions in the affirmative. > >One of their reasons for using Python is to be able to do the following: > >"Redefining methods: > >One of the truly powerful features of Panda3D is that you can stop a >simulation, redefine a method, and start from that point again. This is >done using Python features. Panda3D recursively digs through namespaces to >find the definition of the class or methods and then swaps them for the >new, thus rebinding the new version. There is also special code written to >dig out all the stored function pointers, such as events and tasks, and >replace those as well." > >I think this nicely illustrates what I saw as the conclusion of the reload >thread: if one wants a reload function that does exactly what one wants in >a particular application, one should write it oneself, and with effect, one >can do so. > >Terry J. Reedy > > >

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Python as natural language (was Re: ANNOUNCE: 'goto' for Python
by Ville Vainio April 1, 2004

April 1, 2004

>>>>> "Richie" == Richie Hindle <richie(a)entrian.com> writes: Richie> Entrian Solutions is pleased to announce version 1.0 of Richie> the 'goto' module. Richie> This adds the 'goto' and 'comefrom' keywords to Python Richie> 2.3, adding flexibility to Python's control flow Richie> mechanisms and allowing Python programmers to use many Richie> common control flow idioms that were previously denied to Richie> them. I like it! I especially like the way comefrom maps to how we speak. You know, "come here when you are done with the first file". Programming is hard for the beginners because there really is no direct mapping of many everyday speech idioms, and comefrom goes a long way to redeem this for Python. There is still a long way to go, though. I have some problems telling nouns apart from verbs. Python could innovate here by prefixing all the function names with !. This ought to make the parser faster also, considering that Python startup time has gone up in recent versions. Another gripe of mine is the if-statement. Often what is done is more important than the condition that determines what we are to do in the first place, esp. in situations where the condition is of the form "if the previous command succeeded". This could be easily redeemed by a postfix-if statement: err = foo() dostuff() domorestuff() :if not err This seems pretty elegant, considering that exceptions are a hackish and unnatural way to solve this problem. Python parser would cope with this just fine. -- Ville Vainio http://tinyurl.com/2prnb

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[Twisted] Cookbook?
by F. GEIGER April 1, 2004

April 1, 2004

Does anybody know of a cookbook for Twisted? It's not that helpful for me to see how an echo server is written (can do this with std sockets) and success stories are too little concrete. What I actually want to try is using Twisted in factory automation. So I'm thinking of cookbook topics like "If you want to capture data from an OPC server and put them into a database, then go this way..." or "If you want to notify the production manager of troubles found in production data, then go for chapter..." etc. Probably the way to answer such questions is to try it myself - no problem with that, I'm working thru the examples right now. But if there are shortcuts, I'd like to take them (who wouldn't do so?). BTW, the dox itself seem to be extensive (the book in pdf format has 380+ pages), which is really pleasing. Many thanks in advance and best regards Franz GEIGER

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Re: ANNOUNCE: 'goto' for Python
by Peter Maas April 1, 2004

April 1, 2004

Richie Hindle wrote: > Entrian Solutions is pleased to announce version 1.0 of the 'goto' module. > > This adds the 'goto' and 'comefrom' keywords to Python 2.3, adding > flexibility to Python's control flow mechanisms and allowing Python > programmers to use many common control flow idioms that were previously > denied to them. Great!!! This will enhance Python's yet poor capabilities to write code with a behaviour hard to predict by programmers thereby adding a human touch to the sometimes too clean and dull Python language! Mit freundlichen Gruessen, Peter Maas -- ------------------------------------------------------------------- Peter Maas, M+R Infosysteme, D-52070 Aachen, Hubert-Wienen-Str. 24 Tel +49-241-93878-0 Fax +49-241-93878-20 eMail peter.maas(a)mplusr.de -------------------------------------------------------------------

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ALERT - GroupShield ticket number OB77_1080832483_ESRIMAIL_3 was generated
by GroupShield for Exchange (ESRIMAIL) April 1, 2004

April 1, 2004

Action Taken: The message was blocked because of its subject. To: python-list(a)python.org <python-list(a)python.org> From: Peter Maas <fpetermaas(a)netscape.net> Sent: 257586048,29628412 Subject: Re: test for nan Attachment Details:- Attachment Name: N/A File: Infected.msg Infected? No Repaired? No Blocked? Yes Deleted? No Virus Name:

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ALERT - GroupShield ticket number OB76_1080830688_ESRIMAIL_3 was generated
by GroupShield for Exchange (ESRIMAIL) April 1, 2004

April 1, 2004

Action Taken: The message was blocked because of its subject. To: python-list(a)python.org <python-list(a)python.org> From: Roel Schroeven <rschroev_nospam_ml(a)fastmail.fm> Sent: -492544768,29628407 Subject: Re: test for nan Attachment Details:- Attachment Name: N/A File: Infected.msg Infected? No Repaired? No Blocked? Yes Deleted? No Virus Name:

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Re: GUI Frameworks in Python?
by Peter Hansen April 1, 2004

April 1, 2004

Richie Hindle wrote: > [Peter] > >>I'm curious about the differences with wxPython. Three seconds seems >>unusually long when on a slightly slower machine I can do it in well >>under a second. Was that the first time you ran it? Many other apps >>open? I have over 256MB RAM free when I try this... > > > I tried it on this 3GHz 1GB XP box and it took 3.5 seconds to bring up the > wxPython demo's splash banner. That was with lots of other stuff running and > not having run it before during this session, but with plenty of available RAM > and nothing soaking the processor. Try it after a clean boot or a good long > disk-cache-hammering spell of doing something else - you might find it's > slower than you think. Something's wrong with your box then. :-) Rebooted. No wxPython apps run first. Clicked on Demo icon and said "one thousand and wuh--" and the splash banner appeared. Run it again and I get as far as "one thou--", so clearly there is some difference between the two and it's not pilot error. (Barring the possibility, which always exists, that it still _is_ pilot error. :-) Go figure. (And as I said this is an AMD 2200 with 512MB RAM, XP Pro.) -Peter

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