Mailman 3 August 2006 - Python-list

Re: code blocks in Python
by hungjunglu＠yahoo.com March 25, 2022

March 25, 2022

Skip Montanaro <skip(a)pobox.com> wrote in message news:<mailman.1035.1069703636.702.python-list(a)python.org>... > > You should be able to express the desired semantics of your extension to the > language without requiring us to execute code. I have yet to see an > explanation of why you want > > def c: > x += 1 > > added to the language. I can guess that it binds c to a "code block". How > do I use it? The above is illegal syntax in Python today. Am I supposed to > guess how to use it? That has nothing to do with compile(). Am I supposed > to run it with the exec statement or do you envision me just inserting > > c > > into my code? Skip: being you a Python old timer, I think you are just grumbling for no good reason. :) Before anything else, people are already jumping into implementation details, optimization, syntax, etc. I am barely starting to look at whether there have been previous existing efforts, and if so, why were they discarded, etc. > > What exactly have you given me that I couldn't have done with > > x = 1 > x += 1 > I come back again to repeat it one more time: the compile() function already exists and works in Python. Before you do your posting, please think about the compile() function first. (Do I need to say it one more time? I don't mind.) So, let me try to pretend I am Skip Montanaro, and follow through with the process. (a) OK, I have been told that compile() function exists in Python. (b) I am complaining that I can do x = 1 x += 1 without resorting to codeblocks. So there is no need for codeblocks. Codeblocks are useless, good for nothing. (c) OK, one more time, I have been told that compile() function exists and works in Python. Everytime I talk about codeblocks, I need to think about the compile() function first. (d) Aha! So by analogy, there is no need for the compile() function in Python. I get it now! (e) Wait a second... searching through the Python newsgroup archive I find hundreds if not thousands of messages related to the usage of the compile() function. So the compile() function can't be useless. Either thousands of Python users are wrong, or I have not been careful in my thinking process. (f) Hmm... let me look at those messages and try to understand how people are using the compile() function. (g) Aha! The compile() function is not useless. I know how to use it, now. (h) Aha! Codeblocks are not useless. (i) Aha! So codeblocks are analogous to the compile() function, the only difference is that codeblocks are compiled at compile time. The compile function compiles the code string at runtime. (j) Wait, I think Hung Jung has said everything before in his messages. Bingo! Now you get it. Hung Jung

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IP address to binary conversion
by Jeroen Wolff May 9, 2020

May 9, 2020

Hi, Can somebody help me (a newbee) to convert an ip address to is 32 bits representation? i would like to store these 32bits interger into a MYSQL database together with the mask. Jeroen

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embedding python - PyImport_ImportModule returns null
by jkpangtang＠yahoo.com March 28, 2019

March 28, 2019

I am trying to embed python within a c program, but I can't get PyImport_ImportModule() command to load my module. Please let me know what I'm doing wrong. -- #file func.py def func1(): print "inside func1()" -- //main.c int main() { PyObject *pFunc, *pModule; Py_Initialize(); pModule=PyImport_ImportModule("func"); //fileread.py if(pModule==NULL) { PyErr_Print(); fprintf(stderr,"Failed to load \"%s\"\n","func"); } //etc.... } --- Both main.c and func.py are in the same directory. I run main and get the error Failed to load "func", meaning that PyImport_ImportModule returns NULL. What am i doing wrong? Thanks in advance for the help

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SWIG+Distutils - no harmony?
by m.bless＠gmx.de July 7, 2018

July 7, 2018

Getting courageous I try building 'example.pyd' from the SWIG 'Simple Example' using SWIG and the Distutils. Looks promising but doesn't succeed. I didn't modify 'example.c' and 'example.i'. Problems/questions: (1) Is 'setup.py' ok? (2) BEWARE: What's really shocking: After see (unsuccessful) python setup.py build -cmingw32 the original 'example.c' is GONE AND AWAY - replaced by the wrapper. (3) What's going wrong? Martin Sources und logs following: >----------<>----------<>----------< # setup.py # mb: Is this ok? import distutils from distutils.core import setup, Extension #from distutils.extension import Extension setup(name = "Example 'Simple' from the SWIG examples", version = "2.2", ext_modules = [Extension("example", ["example.i"])]) >----------<>----------<>----------< /* File : example.i */ %module example extern int gcd(int x, int y); extern double Foo; >----------<>----------<>----------< /* File : example.c */ /* A global variable */ double Foo = 3.0; /* Compute the greatest common divisor of positive integers */ int gcd(int x, int y) { int g; g = y; while (x > 0) { g = x; x = y % x; y = g; } return g; } >----------<>----------<>----------< C:\python Python 2.2 (#28, Dec 21 2001, 12:21:22) [MSC 32 bit (Intel)] on win32 Type "help", "copyright", "credits" or "license" for more information. >>> >----------<>----------<>----------< swig -version SWIG Version 1.3.10u-20011211-2004 Copyright (c) 1995-1998 University of Utah and the Regents of the University of California Copyright (c) 1998-2001 University of Chicago Compiled with CC >----------<>----------<>----------< >python setup.py build -cmingw32 running build running build_ext building 'example' extension swigging example.i to example.c c:\pyext\swig\swig.exe -python -dnone -ISWIG -o example.c example.i c:\mingw\bin\gcc.exe -mno-cygwin -mdll -O -Wall -IC:\PYTHON22\include -c example.c -o build\temp.win32-2.2\Release\example.o writing build\temp.win32-2.2\Release\example.def c:\mingw\bin\gcc.exe -mno-cygwin -mdll -static -s build\temp.win32-2.2\Release\example.o build\temp.win32-2.2\Release\example.def -LC:\PYTHON22\libs -lpython22 -o build\lib.win32-2.2\example.pyd swig: Warning. -dnone option deprecated. example.c: In function `SWIG_UnpackData': example.c:363: warning: `uu' might be used uninitialized in this function example.c: In function `SWIG_ConvertPtr': example.c:429: warning: suggest explicit braces to avoid ambiguous `else' example.c:432: warning: suggest explicit braces to avoid ambiguous `else' example.c:438: warning: suggest explicit braces to avoid ambiguous `else' example.c: At top level: example.c:154: warning: `SWIG_TypeQuery' defined but not used example.c:385: warning: `SWIG_ConvertPtr' defined but not used example.c:468: warning: `SWIG_ConvertPacked' defined but not used example.c:537: warning: `SWIG_MakeShadow' defined but not used build\temp.win32-2.2\Release\example.o(.text+0xbda):example.c: undefined reference to `gcd' build\temp.win32-2.2\Release\example.o(.text+0xc35):example.c: undefined reference to `Foo' build\temp.win32-2.2\Release\example.o(.text+0xc6b):example.c: undefined reference to `Foo' build\temp.win32-2.2\Release\example.o(.text+0xc71):example.c: undefined reference to `Foo' error: command 'gcc' failed with exit status 1 >----------<>----------<>----------<

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Re: strange behaviour when writing a large amount of data on stdout
by bokr＠oz.net April 11, 2017

April 11, 2017

On Wed, 23 Nov 2005 18:18:34 +0100, "Fredrik Lundh" <fredrik(a)pythonware.com> wrote: >Manlio Perillo wrote: > >> >>>>> print data >> >> >> >> Traceback (most recent call last): >> >> File "xxx", line xxx, in ? >> >> print data >> >> IOError: [Errno 12] Not enough space >> > >> >errno 12 is ENOMEM (that is, the system did not have enough memory >> >to finish an operation). >> >> However I think the error message is not a good one. >> Better a "Not enough memory" > >the message text is provided by the operating system (or rather, by >the C library). I'm not sure rewriting error messages is a good thing... > >(if Python itself runs out of memory, it'll raise a MemoryError instead) > Maybe there's a bare except: somewhere blocking earlier & perhaps more informative messages? If windows has been running a long time (a few days or a week may be long ;-) it may get fragmented in some smallish memory arena reserved for special things (I forgot what versions, but I wouldn't be surprised if something still had s specialized limit). Does the program involve dynamic generation of desktop icons by any chance? Especially a lot of large true-color ones? I have some faint inkling of some correlation of that and memory problems with still huge amounts of heap memory available. Has the OP rebooted and just run the offending program alone? BTW, if the OP wants to find out how much memory is on the windows system, the amount of memory probably shows in the "about" window of the task manager (the NT task manager will give you a scrolling real-time graph of different kinds of memory usage as well). Also if the OP has windows word editor (probably winword.exe will start it from the console command line), the "about" dialog may have a "system info ..." button that will show memory and a lot more. What that button runs is C:\Program Files\Common Files\Microsoft Shared\MSInfo\MSINFO32.exe on my system. Since it's accessible from Word, I wouldn't think it would be too unsafe to run, but I guess the OP might not want to start diagnostic things on arbitrary devices etc., if that's accessible from his session. Regards, Bengt Richter

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how to create IPictureDisp objects with python?
by Felix Jan. 5, 2017

Jan. 5, 2017

i try to host an activex control in my program . the control has a picture property which only accepts "IPictureDisp" interfaces. does anybody know how to create IPictureDisp objects? thanks.

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Software Needs Philosophers
by Xah Lee Sept. 12, 2016

Sept. 12, 2016

Software Needs Philosophers by Steve Yegge, 2006-04-15. Software needs philosophers. This thought has been nagging at me for a year now, and recently it's been growing like a tumor. One that plenty of folks on the 'net would love to see kill me. People don't put much stock in philosophers these days. The popular impression of philosophy is that it's just rhetoric, just frivolous debating about stuff that can never properly be answered. “Spare me the philosophy; let's stick to the facts!” The funny thing is, it's philosophers who gave us the ability to think rationally, to stick to the facts. If it weren't for the work of countless philosophers, facts would still be getting people tortured and killed for discovering and sharing them. Does it ever strike you as just a teeny bit odd that after a brief period where philosophy flourished, from maybe 400 B.C.E. to ~100 C.E., we went through a follow-on period of well over one thousand five hundred years during which the Roman Catholic Church enslaved everyone's minds and killed anyone who dared think differently? What's weirder is that we tend to pretend it didn't really happen. We like to just skip right over the dominance of religion over our minds for a hundred generations, and think of religion today as a kindly old grandpa who's just looking out for us kids. No harm, no foul. Let bygones be bygones. Sure, there were massacres and crusades and genocides and torture chambers with teeth grinding and eyes bleeding and intestines torn out in the name of God. But we were all just kids then, right? Nobody does that kind of thing today, at least not in civilized countries. We try not to think about the uncivilized ones. It was philosophers that got us out of that Dark Ages mess, and no small number of them lost their lives in doing so. And today, the philosophy majors are the butts of the most jokes, because after the philosophers succeeded in opening our minds, we forgot why we needed them. And if we stop to think about it at all, we think that it was other people, people who are very unlike us, who committed those atrocities in the name of Faith (regardless of whether it's faith in a god, or in a political party, or any other form of mind control carried out by force). We like to think we live in an enlightened age, but we don't. Humans haven't changed significantly in 10,000 years. We're still killing and torturing each other. It's apparently incredibly easy to decide to kill someone and then do it. Happens every day, all around the world. Torture, too. But those people are just people. If they had been born down the street from you, they'd have gone to school with you, been friends with you, learned to program with you, written blogs and comments, never tortured or killed anyone in the name of an idea. They'd have been you. Which means they are you; you just got lucky in where you were born. One of the commenters on my last blog entry expressed the fervent wish that I drop dead. To be sure, they qualified it with “on the internet”. But if they really feel that way, especially about something as hilariously and absurdly unimportant in the Grand Scheme as whether the Lisp programming language has any acceptable implementations, then what does it say about us? Everyone who commented angrily on that blog entry was caught. I caught you, anonymous or not, being a religious fanatic. The only “negative” commenter who doesn't appear to be a religious zombie was Paul Costanza (ironic, since he claims to be the opinionated one), who relegated his comments to pedantic technical corrections. They're welcome, of course; I'm always looking to correct any technical misconceptions I harbor. But they're moot, since even if I was wrong about every single technical point I brought up in that entry, my overall point — Lisp is not an acceptable Lisp — remains largely uncontested by the commenters. Some of them just don't get it, which is fine; no harm in that. If you've been using Lisp for years and years, and you've written books and articles and zillions of lines of Lisp code, then you're unlikely to remember anything about what it's like coming to Lisp for the first time. They're religious because they've forgotten what it's like to be a skeptic. But make no mistake; a substantial percentage of people who take a side in any programming language discussion that devolves into a flamewar know exactly what the other side means, and they want to invoke the Ultimate Censorship: drop dead! Killing someone, after all, is one of the best ways to silence them. You also have to burn all their writings, which is getting harder these days; hence the increased vehemence on the 'net. Those of you who've followed what I've written over the past year or so know where I'm going. I'm taking a stand, all right, and it's a very definite one. I'm finding myself drawn inexorably towards a single goal: stamping out technological religion, because I'm frigging tired of not being able to stick to the facts. FACT: Java has no first-class functions and no macros. This results in warped code that hacks around the problem, and as the code base grows, it takes on a definite, ugly shape, one that's utterly unique to Java. Lisp people can see this clear as day. So can Python folks, so can Ruby folks. Java people flip out, and say “macros are too much power”, or “what do u mean i dont understand u” or “fuck you, you jerk, Lisp will NEVER win”. You think I don't hear ALL that, and much more, in the hate mail I get every day? I sure wouldn't want to be alone with a Java fanatic in a medieval torture chamber, because God only knows what they're capable of. Turn the mirror towards Python, and what happens? Funny, but the Java folks will mail me saying: “yeah, I've always known I detested Python, and you really nailed exactly why. Thanks!” Meanwhile, Python folks are literally frothing at the mouth, looking for the “Kill That Bastard” key on their 101-key keyboards. I turned the mirror towards Lisp yesterday. Had to go to the bathroom like nobody's business, and my wife was expecting me home any minute, so I rushed it out: just a few thoughts here and there. So the Gorgon only caught the tiniest glimpse of itself, but hell evidently hath no fury like that of a Lisper scorned, and all that. It doesn't matter that I rushed it out. I'm glad I did; spending any more time on it, trying to get it “right” by looking up useless factoids like how you can override length's non-polymorphicness with some weird setting (when it plainly should just be the default), would have had the exact same net effect: Lisp zealots would have found some way to turn it into a flamewar. And I'd have been out 2 or 3 more hours. Let's call it a troll, then, because it was poorly researched; it was just some months-old recollections of pain I'd gone through last year trying to commit to Common Lisp, after another year of trying the same with various flavors of Scheme and finding them all wanting. As far as I'm concerned, Lisp is unacceptable today; it's my opinion and just that, but I'll stick with it. I still need Lisp; after you learn enough of it, it becomes part of your soul. I get my fix hacking elisp, and I do a lot of it. The commenters are quite right; I've never written anything substantial in Common Lisp, because in each of my serious attempts, there was too much friction. Risk/reward wasn't high enough, and believe me, I wanted it. But after many attempts, I've given up on Common Lisp. They won't let me use it where I work, and there are probably more Lispers per capita where I work, including some famous ones, than at any other big company in the world. If we can't use it where I work, then it's frigging unacceptable; that's the shortest proof I can offer. What I'm far more interested today is the situation that arises if you consider my post a troll. I'm far more interested in the social consequences of working in a world filled with religious fanatics of different religious persuasions. Especially given that it's a world in which “natural religion” has, by and large, been marginalized through the work of philosophers. [ • Peter Siebel is the author of the book Practical Common Lisp, 2005. ( http://gigamonkeys.com/book/).] Let's look at this world in a little more detail, starting with Peter Siebel's comment, which I believe is the most interesting. Peter said: I was trying to figure out why on earth you spent so much time writing about something that you apparently don't like. Then it hit me: HCGS↗. So thanks for your help. His first sentence speaks volumes about the sociology. His viewpoint is exactly what they teach us all as kids: If you don't have anything nice to say, don't say anything at all. We like to think people have a right to believe whatever they want, and that it's not nice to say mean things about other people's beliefs, especially when their livelihoods are at stake. That's where philosophers come in, folks. They pick your beliefs apart and show you in unforgettable ways the consequences of what you believe in. I'm no philosopher; I know basically nothing about it, but I can tell you I wish fervently that some great philosophers would come along and effect change in our technical society. Because if nothing else, I can see the consequences of the way we're thinking about things. One of many such consequences is that languages aren't getting any better, and the worst offenders are Lisp and Scheme, which by rights should be racing along the innovation curve faster than their supposedly less capable peers. But they've stagnated worse than any other non-dead language I can think of.[1] Programming languages are religions. For a long while now I've been mildly uncomfortable calling it “religion”, but I don't feel bad about it anymore. They're similar enough. At the top of the language religion is the language itself; it serves as the deity and the object of worship. Like any other organized religion, there's always a Pope (or a politburo chairman, in countries where the government has brutally set itself up as what is for all intents the religion of choice): a spiritual leader that gives the religion the human touch. This person is almost always the language designer, of course. In Lisp's case it's complicated, because McCarthy, Sussman and Steele aren't very active as spiritual leaders for their languages anymore. Every major organized religion is a heirarchical government, and programming languages are no exception. You'll find equivalents of cardinals, bishops, priests and laity in programming language camps: the closer you are to the fire, to the spiritual center, the higher your rank. It's a great way to quantify your perceived self-importance: a high-score list, in effect. Great for the ego, but it makes you a piss-poor debater, because you're so emotionally invested in your status. You'd think your rank would be accrued by virtue of your technical and/or documentation contributions, but in practice it's usually more of a function of how many converts you've gained, how many followers you have, how much you've been spreading the Word. [• Paul Graham is a lisp dignitary. He is well known for having sold his ecommerce software written in lisp to Yahoo.com for $49.9 million, among other things. See Paul Graham↗ and http://www.paulgraham.com/ ] That's why Paul Graham isn't the Pope of Lisp. He's eminently qualified, but unfortunately he's a heretic. Notice that almost none of the commenters on my last blog mentioned the PG argument I made. The only one who did (as of this writing) tried to make it an argument for Common Lisp. Let's face it: you can't give those heretics too much press; people might start listening to them! Peter, are you beginning to understand why I write so much about something I apparently don't like? It's because I wanted to like it but found it fatally flawed, technically and culturally. It's as if I were a would-be convert to Roman Catholicism, but I can't bring myself to commit because I've seen too much of their role in creating a history that ironically we all wish we could rewrite. I was born and raised a Roman Catholic, and I renounced it when I was thirteen years old, after my Uncle Frank (a devout terrorist Catholic if there ever was one) told me to stop reading the Bible, that it would “really screw a person up” to do that, that you needed someone to interpret it for you. That wasn't the only reason I renounced it, but it'll suffice for our purposes. Technologically I was born and raised an assembly-language programmer; at least that's what my first real job was, for 5 years after I got my CS degree. Assembly is just flagellation, though, and damned uncomfortable at that, so I joined the Church of Java for fully seven years. And practically at the very moment I'd finally tired of chafing at Java's limitations, Paul Graham came along and through his early essays, showed me Lisp. What a great new religion! Problem is, each time you switch religions, the next one has less impact on you. Once a Catholic, always a Catholic, they say. I don't know what that means for me, since I was raised by the assembly-language wolf, but it appears to mean that I'm never going to be enthralled with another programming language. And now that I've swallowed the red pill, what choice do I have? I need to try to show people what's out there. Interestingly, it was Peter Siebel's most excellent book, Practical Common Lisp↗, that played the role of Uncle Frank and killed my desired to continue with Common Lisp. Peter was the first person to show me beast's underbelly. Every other Lisp book had pretended it was pure and beautiful and uncorrupted, because they left all the nastiness out as “implementation-defined”. Once I saw what you really need to do in order to build something resembling a portable Lisp code base, and then had a few runs at it myself, I threw in the towel. I much prefer Lisp the idea to Lisp the implementation.[2] [ • Fyodor_Dostoyevsky↗, David_Hume↗, Aristotle↗, Jean-Paul_Sartre↗, Ben_Franklin↗, Galileo_Galilei↗, Bertrand_Russell↗, Albert_Einstein↗ ] I can tell you this: I've tried writing this essay for a year. I've tried fully a dozen times. I've tackled it from a dozen angles. I've wanted to say it — software needs philosophers! — so many times, in so many ways. We need great thinkers — the Fyodor Dostoyevskys and David Humes and Aristotles and Jean-Paul Sartres and Ben Franklins and Galileo Galileis and Bertrand Russells and Albert Einsteins to show us the way through the Software Dark Ages we're in today: a time that will doubtless be remembered as every bit as mired in darkness and ignorance as the Dark Ages themselves. But I've failed. This isn't the essay I wanted to write, because I'm neither a great thinker nor a great writer. However, you might be: if not now, then perhaps someday. So I think it's better to get the idea out now than to hoard it in the hopes of someday writing a world-changing essay. For those of you who were surprised at the suddenness and vehemence of the Lisp community's backlash to my little rant, I hope I've helped shed a little light, helped you see its inevitability. Basically they've had a lot of practice. Lisp is one of the oldest technology religions, and they've both experienced and doled out their share of religious persecution. But that's not the lesson you should take away. The lesson is that they are you. Whenever you hear someone ranting about something you take for granted as wonderful and praiseworthy, and you're wondering why they don't leave well enough alone so we can all get back to our incestuous cheerleading, just remember: we went from the Dark Ages to our reeeeasonably enlightened society today by questioning our most cherished beliefs. So keep questioning them. [ • R6RS refers to the Scheme Lisp language's upcoming specification. See Scheme programming language↗ ] [1] Yes, I've read all of R6RS. It's a lukewarm compromise that punts on most of the important issues. It's not going to make Scheme any more successful than it is today, which to me feels practically criminal; it was their one big chance to break out of the rut they're in. But it doesn't matter. Let's pretend this footnote is just a troll. If your hackles went up, then you're a techno-religious zombie, and I hope in my lifetime to find you a cure. Try your best to think about that long and hard before responding. [ • SLIME is a emacs mode for lisp programing. See http://common-lisp.net/project/slime/. ] [2] For the record, the commenter I agree the most with is the one who said the problem basically boils down to an IDE issue. SLIME doesn't cut it, either, as beautiful as SLIME is. Can't use it on Windows to save your life, for instance. But that's one of a thousand problems with the Lisp IDE situation; it's pointless to try to discuss them all in blogger. It's probably pointless to discuss them at all, because it's just going to make me more miserable that no decent IDE exists for Lisp, except for Emacs-as-Elisp-IDE. Which is why I get my Lisp fix by hacking elisp these days. ---- This post is archived at: http://steve-yegge.blogspot.com/2006/04/software-needs-philosophers.html and http://xahlee.org/Periodic_dosage_dir/_p/software_phil.html This essay is reported with permission. Xah xah(a)xahlee.org ∑ http://xahlee.org/

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degrees and radians.
by Jim Richardson Sept. 8, 2016

Sept. 8, 2016

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 I am trying to get the math module to deal with degrees rather than radians. (that it deals with radians for the angular functions like sin() isn't mentioned in the docs, which was sort of an eyeopener :) I can't find any info on doing this. I can convert from-to degrees in the code calling the function, but that's a bit clunky. Any pointers to an FM to R? :) -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE804+jd90bcYOAWPYRAt9KAKCuqeC4ozuXSaKZ5xY27Wv+k04QuQCcCrCZ WyichPnKgXo+GaDdAebsaeU= =h+vc -----END PGP SIGNATURE----- -- Jim Richardson Anarchist, pagan and proud of it http://www.eskimo.com/~warlock Linux, from watches to supercomputers, for grandmas and geeks.

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ANN: pygene - genetic algorithms package
by aum Aug. 22, 2016

Aug. 22, 2016

Hi all, I looked at a few genetic algorithms/genetic programming packages for Python, and found them somewhat convoluted, complicated and counter-intuitive to use. So I've written a genetic algorithms package which I hope will be more approachable to beginners. The first release of pygene is up at: http://www.freenet.org.nz/python/pygene The package includes full api documentation, and an implementation of the travelling salesman problem, plus a couple of simpler cases. -- Cheers aum

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How to get all IP addresses in python?
by Yun Mao Feb. 25, 2016

Feb. 25, 2016

Hi. I did a little homework on google for this question. The answer was: >>> import socket >>> hostname = socket.gethostname() >>> ip = socket.gethostbyname(hostname) >>> print ip 192.168.55.101 But what if I have several interfaces, say eth0, eth0:1, eth1, etc. How to get all of them? It would be a little undesirable if people suggest to parse the result of ifconfig because I in particular want the code to be cross platform. Thanks a lot! Yun

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